Okay new thread. And since SAE dropped the mini it's now SAE Baja. Post of pics and specs of what you guys have. I will be dropping by our shop sometime this week and grabbing some photos. Our rear uprights are pretty trick.

Frame

http://www.pirate4x4.com/forum/gallery/files/5/6/3/9/DSC00312.JPG

We'll be at Peoria this year, taking 2 cars (hopefully).
I have a question for sac state, did they give you much crap about your muffler placement so close to your feet? What sort of gaurds did you need around it?

Ill get back with some pics a little later

We'll be at Peoria this year, taking 2 cars (hopefully).
I have a question for sac state, did they give you much crap about your muffler placement so close to your feet? What sort of gaurds did you need around it?

Ill get back with some pics a little later

we originally had it mounted to the motor, and then a post muffler exhaust pipe to route the fumes out the side... using some 3.5" exhaust tube - so no engine losses...
but tech Jason didnt like that, and said a remote mount muffler would be better... we had to search ALL OVER to find tube with an ID of 1.25 and ended up with some Inch and a Quarter SCHD 40 pipe weighing in at like 12lbs per foot to remote mount the muffler...

we had a sheild over it with the words 'caution - HOT' on it in red paint pen, to prevent someone from touching it, but other than that - it wasnt an issue...

their big concern was that the exhaust fumes were headed towards the driver... so dont do that :D


some stuff for CSUS this year -
our front knuckles - :grinpimp:

http://www.opiebennett.com/MiniBaja/CSUSMiniBaja3208/knuckleandbearingsleeve.jpg

http://www.opiebennett.com/MiniBaja/CSUSMiniBaja3908/stp82542.jpg

rear link mounts -
http://www.opiebennett.com/MiniBaja/CSUSMiniBaja3908/stp82546.jpg

rear suspension without shock hoops -
http://www.opiebennett.com/MiniBaja/CSUSMiniBaja3908/stp82549.jpg

http://www.opiebennett.com/MiniBaja/CSUSMiniBaja3908/stp82552.jpg

Frame -
http://www.opiebennett.com/MiniBaja/CSUSMiniBaja22408/stp82464.jpg

http://www.opiebennett.com/MiniBaja/CSUSMiniBaja22408/stp82473.jpg


full thread here:
http://www.rockhardxj.com/viewtopic.php?f=3&t=1627&st=0&sk=t&sd=a

any reason you guys are going with solid axles again? I like the knuckles and gussets, nice work.

any reason you guys are going with solid axles again? I like the knuckles and gussets, nice work.

Looks solid in the rear and A-arms up front

Solid axles are tough! Easy to link and mount. Way less moving parts then independent and stronger. Trophy truck=solid rear axle.

Trophy truck=solid rear axle.

Not for long... Pflueger and some others are going to be soon running IRS trucks. Keep an eye out for the new generation of TT to come. Its the start of a new trend, we'll see if it works as well... Pflueger is pretty confident it will be.

http://pfluegerracing.com/08_SF_Test.mov

Solid axles are tough! Easy to link and mount. Way less moving parts then independent and stronger. Trophy truck=solid rear axle.

They only use them in the rear due to the problems with getting the IRS joint to survive the operating angle due to the large amounts of travel.

For our application (light weight underpowered cars) IRS handles everything better at speed. IRS can be swept back matching the direction of impact and makes you faster through the rough stuff. It's easier to tune to vary your understeer/oversteer behavior. Roll centers move in a straight line which keep the suspension response constant through out your travel and the shock rate is progressive.

any reason you guys are going with solid axles again? I like the knuckles and gussets, nice work.

the same reason we have power to all 4 corners -

because no one else does! :D :flipoff2:

No one on our team knows a damn thing about A-Arms, or any other independent suspension system... The team members backgrounds are in 4x4 rock crawling, drag racing, tractor driving, and karting... We're taking a stab into the dark with the front end, and fully expect to have to re-do the front IFS geometry a few times in testing...

Solid rear axle is reliable, strong, and keeps our rock crawl prowess :D

the same reason we have power to all 4 corners -

because no one else does! :D :flipoff2:

No one on our team knows a damn thing about A-Arms, or any other independent suspension system... The team members backgrounds are in 4x4 rock crawling, drag racing, tractor driving, and karting

Yeah thats cool. That were we started too. I think my first year the entire team was into rock crawling and we figured it all out eventually. :D

There are plenty of team still running swingamrs and a linked rear is leaps and bounds ahead of that. I like the 4 wheel drive theme, we though ahrd about it for two years (actually a light duty front partial drive system(open) but we have never had a course were it would have helped enough.

Yea the effort, time, and over all weight penalty of 4 wheel drive has been a huge headache. We would have been driving the vehicle already but we really like how unique the car is. We also know for a fact that if we continue to develop 4wd we can make it fairly competitive and just as reliable as the 2wd cars. Due to our budget, and lack of team members it is not feasible to try and go for an over-all win so the next best thing is to pick an event and break everyone else's back, which is exactly what we did last year :) This year, we HOPE to win the rock crawl but would also like to be somewhat competitive in the other events. If we can attain that goal, then I say keep up the research and try an IRS and a better IFS as well next year. Besides, it wouldnt be fun this year if the tech inspectors didnt think "Jesus christ! Not again! WTF Is wrong with those guys!?" Anyways, hope this sheds some light on what we were thinking, and I hope to see you guys at comp again this year!

Ken M
CSUS Mini Baja - Treasurer

Nope thats cool and I think you guys can do well in the direction you are going. The big thing in doing well is not completly changing your design but perfecting and optimizing it. I think even if you had some sort of way to maybe not tranmit full power but some to the front or maybe just open in the front would work well.

And yeah when one team blows away one event, like you guys did, it really effects the scores of everyone else as the spread grows quite a bit, which I think it good.

A front driveshaft disconnect is in the works as we speak so as to minimize the losses during the endurance race where 4x4 can be considered a waste. Last year we had locking hubs which helped but we ended up staying in 4wd with locked rear and open front throughout the race.

made an A-arm...

:D

http://www.opiebennett.com/MiniBaja/CSUSMiniBaja32808/stp82664.jpg

we originally had it mounted to the motor, and then a post muffler exhaust pipe to route the fumes out the side... using some 3.5" exhaust tube - so no engine losses...
but tech Jason didnt like that, and said a remote mount muffler would be better... we had to search ALL OVER to find tube with an ID of 1.25 and ended up with some Inch and a Quarter SCHD 40 pipe weighing in at like 12lbs per foot to remote mount the muffler...

we had a sheild over it with the words 'caution - HOT' on it in red paint pen, to prevent someone from touching it, but other than that - it wasnt an issue...

their big concern was that the exhaust fumes were headed towards the driver... so dont do that :D


some stuff for CSUS this year -
our front knuckles - :grinpimp:

http://www.opiebennett.com/MiniBaja/CSUSMiniBaja3208/knuckleandbearingsleeve.jpg



We did knuckles like that in the rear of the 05 auburn car, they worked well for a single race, but I would suggest welding plates to the back of them (fully box them). I've seen them crack right at the weld between the plates and the center bearing support (fatigue failure). Good luck!

made an A-arm...

:D

http://www.opiebennett.com/MiniBaja/CSUSMiniBaja32808/stp82664.jpg

Nice! :D

I like those knuckles, too, but I have to say Jwitz is right about fully boxing them. We've used those knuckles in the last few years since he's been gone, and after making about 50 of the bastards, I've seen how touchy they can be at times. Your plate thickness is different then ours, though, so you might be able to get away with it, just keep checking them for deformation during testing.

I'll go ahead and throw up some pics of Auburn's 08 car. Nothing terribly special, the usual Auburn car; short, CVT, and as simple as possible -

Frame -

http://farm4.static.flickr.com/3024/2418920290_7bbe8827f2.jpg?v=0

Our version of plate knuckles (on an older car) -

http://farm4.static.flickr.com/3035/2418920404_34ae05a2d5.jpg?v=0

From testing last saturday -

http://farm4.static.flickr.com/3125/2418920416_bafc7b1643.jpg?v=0

Yours truly and my little brother (our second driver). This year's seating position is amazing compared to previous cars -

http://farm3.static.flickr.com/2369/2418920438_41567f9757.jpg?v=0


Jeremy

ill have to get some pic of our car rolling, did some testing today, it's fast. faster then last year...

We have been beating on ours for a while now, but we are still plagued by our CVT.
We are running a Comet 780 and the damn thing just will not work, when driving it trys to bog the engine all the time, typically taking it down to 2400 rpms. If we pull the rear end off the ground it will wind up to 3800 no problems. We have been changing the ramp angle in the rear and springs with little effect. As far as I know the front only controls engagement speed, so it shouldnt be our problem.
We should have gone to a different CVT this year, I am really sick of this stupid thing.
If anyone has any insight to this thing let me know.

We have been beating on ours for a while now, but we are still plagued by our CVT.
We are running a Comet 780 and the damn thing just will not work, when driving it trys to bog the engine all the time, typically taking it down to 2400 rpms. If we pull the rear end off the ground it will wind up to 3800 no problems. We have been changing the ramp angle in the rear and springs with little effect. As far as I know the front only controls engagement speed, so it shouldnt be our problem.
We should have gone to a different CVT this year, I am really sick of this stupid thing.
If anyone has any insight to this thing let me know.

Keep playing with the spring in the rear, you can also change the preload on the spring as well. We have used them and done good.

This is going to be long, sorry for the novel, but I've done a lot of writing on CVT tuning. Also, if any of your teams use this to help, and beat us at comp, you owe me a keg :flipoff2:(this is basically 4 years of my research, boiled down to one page)-

I've never played with the 780, we use CVTech stuff, but I may be able to help. I've done some pretty extensive tuning programs with ours, and what I've found is that a) the most important clutch to tune is the drive clutch, and b) clutch balance is essential, of course, and tuning reactions should be handled much like you would handle FD tuning; that is, for major changes, tune the drive, for minor changes, tune the driven.

Generally, the primary weight choice controls engagement rpm and max rpm, along with shift rate and linearity (however this one is actually a balance with secondary spring rate/preload). Shift rate and linearity is also controlled by the slider/roller ramp angle. In the secondary [driven], spring rate controls the downshift rate, and the spring rate and roller/slider ramps are a balancing system with the primary to control shift rate and linearity.

For your issue, jeepermat, there could be several big factors. Because it's shifting down to 2400 rpm (almost right at max torque), that means the cvt is actually doing its job fairly well, it's trying to find the optimum torque/ratio balance to accelerate the vehicle. This doesn't mean it's tuned properly, just that it's not broken in any way.

I would look first at the FD ratio. For 22-26" tires, I've found the best initial ratio to be between 35:1 and 55:1, with the ratios in between those being a personal choice to balance accel. and top speed. Anything lower than ~30:1 and you'll have major accel issues, and the top speed side will show diminishing returns based on rolling resistance and aero (we ran a fairly complete hypothetical sim a few years back that showed that due to a baja cars rolling resistance and aero drag, the maximum top speed for a baja car, running a 100% efficient drivetrain, is 36 mph. Most teams that give top speed numbers higher than that mean that their maximum ratio can yield that high number, not the actual complete system). Anything higher than ~60:1 and you'll start to see serious deminishing returns on torque (due to both diminishing rotational acceleration rates, and wheel spin), meaning you're sacrificing top speed for almost nothing. Due to the differences in weight between our vehicle and the general baja population, I would say to err on the higher side of those ranges, so that you can maintain the acceleration rates needed for short events (don't worry, I'm not calling your car fat, I just don't know which school you're from, and so I don't know what your cars usual weigh)

Next, look at your total drivetrain efficiency. Add all your efficiency connections up, and see what your theoretical efficiency is around. A cvt is going to run generally at ~95% (I was told this by an old baja captain, I can't prove it myself yet), although I have heard of numbers as high as 98%. For each spur gear mesh, we take away another 2%, for each bearing, ~.5%-2.5%, depending on the bearing style, and each chain sprocket, another 1% (this one is entirely arbitrary, we don't have the instumentation to determine chain efficiency, so we just use half of a gear mesh). Your general efficiency is going to tell you a lot of what is going on.

Next, look at the CVT center distance. Different CDs are going to yield different effieciencys and ratio ranges (that one is tricky to realize, most companies give you a set range for that CVT, but it actually changes slightly with CD, and the range they say is for one single CD). Unfortunatly, both are entirely unique to individual CVT models, and belt choice can change them as well. A better thing to look at is CVT CD versus Belt CD. A 'too loose' belt won't yeild proper acceleration, due to slippage, and won't be able to reach full speed, because there is slack in the ratio. It will also cause belt slap (a cause of additional efficiency loss due to vibrational slippage). I would say this is not your problem, because a loose belt is going to allow the engine to run higher RPMs. A 'too tight' belt will give you excellent acceleration and will reach top speed, but unfortunatly will also yeild efficiency loss due to heat after a while, loads of sheeve wear, and a ton of belt stretch that can lead to belt slap and belt side angle deformation and wear (the side angle being the most important part of the belt; think of it like a tire contact patch). This one may be part of your problem, but I doubt it. It's just something good to look at.

Finally, start in on the CVT weights and springs. Lighter weights and springs, along with lower ramp angles, are going to give you higher engagement rpms [drive weights here], higher max rpms [both], decreased downshift rate [secondary springs here], and lower driven torque [drive]. The lighter stuff will also give you faster shift outs (due to decreased rotational mass, for the primary, and decreased required shift out force for the secondary) IF the shift force can overcome the vehicles rolling resistance, weight, and drivetrain effeciency properly. As a corollary to shift rate, the vehicle is likely to see very good initial accelerations (the first 75 ft.), however, slower acceleration on longer runs (150-225 ft.) These weights are generally used for cars with lower total weight or higher initial FD ratios (the higher ratio being in balance with the decreased driven torque). Lighter primary [drive] weights could lead to engine bog when the total shift force necessary exceeds that which those weights can produce (an example of this would be a low ratio car on acceleration, the torque multiplier just isn't there). This bog would be long and drawn out, and I have a feeling this one might be your issue. Lighter secondary springs can lead to slight engine bog, as the shift rate tries to exceed the vehicles speed, but you have to be pretty far off for this to happen, and generally you will actually see belt slip (i.e. increased rpms) over engine bog in this case. The bog is this case is slight and cyclical, meaning that as the overshift occurs, the engine bogs to catch up and balance necessary torque (50 rpms or so), and then it overshifts again.

Heavier wieghts/springs and higher ramp angles are going to give you lower engagement rpms [drive], lower max rpms [both], increased downshift rates [secondary, though ramp angle might not be a factor in this one, just spring rate], and higher driven torque [drive]. You will see slower shift out rates, due to increased rotational mass for the primary, and increased shift out requirement forces for the secondary. Again, and opposite of the lighter drive weights, you will see lower acceleration in low speed or short runs (to 75 ft), but higher acceleration rates on longer straights (150-225 ft). Higher weights can lead to engine bog, as higher primary weights force the engine to work harder to rotate the clutch, and higher secondary weights increase the necessary force required for shift out. The first case leads to long bog periods, but the car will still be accelerating quite well (although certainly not at maximum rate).

I'll go ahead and take a second to talk about shiftable boxes and their CVT tuning requirements. Last year, we had a 'ground' shiftable box. It started as a fly shiftable box, but I'll go ahead and save anyone the effort of designing a fly shiftable box around a CVT by saying - Don't try it, Things explode. When tuning our CVT around the 2 speed (which, btw, I am of the firm belief that CVT tuning should be done the long way, I don't bother with DOEs or simulations. My tuning book requires no less than 360 acceleration runs for our CVT alone. Last year we ran around 1100 before SDSMT, as I also tuned around different tire diameters, sprockets, and the 2 speed. That may seem like a lot, but with a proper set of photogates, it can be accomplished in 3 evenings)... anyways, while tuning the 2 speed, I found, surprisingly, that the setup we deemed proper for first gear, was also the setup we deemed proper for the second gear. We certainly saw differences in times and speeds, however the shift rates were remarkably similar. I haven't determined if it is due to the gap between gear ratios being too similar for shift rate differentiation, if the fact that the efficiency was the same for both gears (we used a dog setup), or if it's related to the vehicle weight (or a combination of all 3). If either of you test a shifting setup and find the same thing, let me know.

I hope that helps, let me know if you have any questions or issues. Oh, and if it does help, let me know what you specifically changed to better the problem so I can add that to my research data notes.:) Also, having written all of that, I'm gonna brag for a second, my ego is too large to pass it up - The other night, in the test trim seen above, we managed to run a photogated 5.198 in the 150', with a top speed of 33.2 mph at 300'. Anyone who looks at the accel results from SDSMT last year will be able to tell how excited I am about that.

Jeremy
Auburn Baja

Why do you say a shift-on-the fly box won't work?

Sorry, I should have clarified. A 'clutchless' gear box with a CVT will not work for fly shiftable (unless you have developed a new system that I hadn't considered).

The CVT downshift rate is not high enough to match to the new RPM rate inside the gearbox in the time it takes to shift. You would have to have sufficient throttle control to very carefully rev match the cvt, with a downshift time of about 2 seconds (if you got the rev match spot on). During that time, the car has slowed considerably, due to rolling resistance, so you end up chasing the rpms down to 0 speed. With a clutched system, you would see the same problem, however chasing the rpms would be considerably easier.

Basically, our system used a sequential gear set that could be shifted without the use of a clutch, and we were counting on belt slip to allow us to change the RPMs of the secondary quickly during a shift. What actually happened is that the RPM change caused the secondary inner sheeve to snap turn off the ramps, and then slam home again. It sounded like a small cannon, and after the 6th shift, it broke all the slider pucks off the CVT and we scraped it.

Damn. We're using a Comet 40 (2.43:1 low, 1:1 high) driving a Honda Rancher 5-speed. We've run manual transmissions every year and I never use the clutch, just back off the gas and grab the next gear. If your timing is decent, it just pops right in. Same for all my motorcycles. I guess my question would be, what does a CVT do when you back off the gas? I figured you back off for a second and with no load you just grab the next gear, stomp on it, and the CVT sees a torque change and corrects. Were you guys backing off, or just slam shifting? None of us really understand CVTs (hence the use of sequentials for 3 years now). Thanks.

Thanks for all that, we will definatley be putting all of that info to use.
We have a fairly light car at ~390 lbs, this was us last year at SDSM.
http://img201.imageshack.us/img201/2904/dsc0122ds9.jpg (http://imageshack.us)

And here we are being denied cause of this damn CVT
http://img177.imageshack.us/img177/8758/dsc0228ds7.jpg (http://imageshack.us)

our car has dreams of being 390lbs... :D

our car has dreams of being 390lbs... :D


390 was so last year... :flipoff2:

350 is where it's at!

No kidding. One of these days we'll make it. We switched to aluminum suspension this year and it still weighs the same, if not more. Should save a little weight on flotation and the handling is exponentially better, so I'll take the extra weight (about 450 dry w/o flotation). Our other car, well... be prepared to be amazed at Illinois (assuming I can get the whole CVT/transmission thing figured out).

Wes Thomas
Missouri S&T Baja

390 was so last year... :flipoff2:

350 is where it's at!

someday - if we can be convinced of a way to take 1st place in the rock crawl with a 2wd, we might be in that range...

CVT to rear axle shafts, IRS, IFS, .020 thick aluminim firewall... 325 would be cake... you'all got it easy...:laughing:

solid rear axle, front and rear wheel drive, locking diffs, 16" of front wheel and 12" of rear wheel travel... that adds up real quick... we have 8 u-joints in our driveline, chain, and a CVT belt! :eek:

someday - if we can be convinced of a way to take 1st place in the rock crawl with a 2wd, we might be in that range...

CVT to rear axle shafts, IRS, IFS, .020 thick aluminim firewall... 325 would be cake... you'all got it easy...:laughing:

solid rear axle, front and rear wheel drive, locking diffs, 16" of front wheel and 12" of rear wheel travel... that adds up real quick... we have 8 u-joints in our driveline, chain, and a CVT belt! :eek:

ha, 325 would be tough for use. Maybe not for some of these pint sized cars but our tend to be one of the larger cars at the comps, well for the 2wd rigs. :flipoff2:

Really had to watch weight to get where we were last year and even more so this year.

And thats pretty quick, not sure what our is running yet, we did a pile of test Sat. but they never told me what the times were just keep running. And that the way we tune them, run after run.

Thanks for all that, we will definatley be putting all of that info to use.
We have a fairly light car at ~390 lbs, this was us last year at SDSM.

...And here we are being denied cause of this damn CVT


Ah, yeah, I remember that little debacle. We felt for you guys, the previous race we had been disqualified from a 2nd place endurance finish because of a damn typo.

And damn, if I had known you were on a top ten team, I would have kept my mouth shut.:flipoff2: When you go to try and pass me this year, just keep that keg of beer in mind. ;)

Were you guys backing off, or just slam shifting? None of us really understand CVTs (hence the use of sequentials for 3 years now). Thanks.

I was letting off. We were hoping for the same thing you guys are, that the secondary would correct much quicker than it does for us (the comet might be different, it IS a lighter clutch system).

As for understanding it, it just takes a long, long, long, fucking long time, and that's just so that you start guessing better than the next guy. I still don't understand a lot of it, after 4 years, but I make pretty good guesses.

Shaved another .15s off our 150 time tonight with some custom weights I made. :D

Jeremy
Auburn Baja

And damn, if I had known you were on a top ten team, I would have kept my mouth shut.:flipoff2: When you go to try and pass me this year, just keep that keg of beer in mind. ;)

Imagine what the car will do with a working CVT!

Thanks again

Well then, guess I'll let you know how it works in a couple weeks once we get back from Tennessee and I have a chance to finish it.

Jeepermat, do you guys have the correct driven/drive spacing and correct belt for the 780, we had similar problems once when we swapped a 790 belt in by accident and its longer.

Yea we ended up grinding about 30 grams off our drive weights and it works great. We are testing a few more things.
We originally thought our alignment may be off, we built a pretty precise jig to get both shafts lined up, it helped us buy about 50 rpms. We have it interchangable with 780 and 790 stuff, but has 2 different belts.

Well, how'd everybody do at Tennessee? We sucked. Bad. Buying a steel +2 kit for the front suspension to replace the aluminum stuff and getting new rear CVs and custom axles along with stiffer coil springs. And I've got 3 weeks to build another car. Fun.

...Buying a steel +2 kit for the front suspension...WTF is a +2 kit?

A +2 A-arm kit. An aftermarket set of control arms, each one 2 inches longer than factory for a total track increase of 4 inches. It keeps us about where we are right now with our current fabricated aluminum ones, but I don't have to worry about breaking and not being able to fix them in the field. We may have to fab some new shock mounts since the ATV arms mount the shock to the lower A-arm and the aluminum ones we made mount it to the upper.

looking at some pics from Tennesee competition...

We're not the only team who thought a solid rear axle might be cool-- check this 4 link! -

Univ of Illinois - Urbana Champaign's car
http://farm3.static.flickr.com/2163/2466135650_4f729824aa.jpg?v=0

and it looks like South Florida kept the wing!
http://farm4.static.flickr.com/3080/2466167094_61a2749b4c.jpg?v=0


Bell crank rear suspension on Virginia's car...
http://farm3.static.flickr.com/2356/2465300333_0464afd252.jpg?v=0

Kansas state's interesting front suspension arms... kinda TTB ish -
http://farm3.static.flickr.com/2244/2466125970_4257c0d7be.jpg?v=0

all of these pictures arent mine, i took them from here:
http://www.flickr.com/photos/ogburn/sets/72157604883002522/

linked from here:
http://forums.sae.org/access/dispatch.cgi/bajasae_pf/docProfile/102346/d20080505124113/No/t102346.htm

did a little testing today...

http://video.google.com/videoplay?docid=8057437295616239372&hl=en

:D:D

Didn't go over... felt REALLY light though!

did a little testing today...

http://video.google.com/videoplay?docid=8057437295616239372&hl=en

:D:D

Didn't go over... felt REALLY light though!

Your to tall!

Poly's was working flawlessly today :)

that wing is so gay, hopefully it gets ripped off again.

that wing is so gay, hopefully it gets ripped off again.

I agree, I think it is total bullshit that they are able to tape that bitch back on.

A friend of mine told me that we(Virginia Tech) took 3rd overall at the Tennesee competition. Is that accurate?

Yeah, it's true.

A friend of mine told me that we(Virginia Tech) took 3rd overall at the Tennesee competition. Is that accurate?

Good job :beer:

Anyone else do well?

Thanks. I'm not affiliated with the team in any way, just know some people who are on it, and am proud of my school. :D

Nah. The wing is cool and it works, too. Get ready to see another in Illinois. This one won't get ripped off, though.

that wing is so gay, hopefully it gets ripped off again.

i heard they got penalized a lot for not changing the necessary amount on the car since their top ten in the midwest last year.

Nah. The wing is cool and it works, too. Get ready to see another in Illinois. This one won't get ripped off, though.

bullshit, an a car that never hits more then 35mph it's just dead weight. Hell even half the FSAE cars don't run wings cause of the lower speeds they get and it's still a huge controversy debate among them. If there are any trees or it's rolled I bet it will come off.

i heard they got penalized a lot for not changing the necessary amount on the car since their top ten in the midwest last year.

Well good, it's total BS that they got away with it last year as their significant redesign.

The only thing I see that wing doing is helping the car not nose over in the air

The only thing I see that wing doing is helping the car not nose over in the air

Which if you hung a 5lb weight or whatever that thing weighs in the same spot it would have the same effect, or if you paid closer attention to your weight distribution, or shock valving.

bullshit, an a car that never hits more then 35mph it's just dead weight. Hell even half the FSAE cars don't run wings cause of the lower speeds they get and it's still a huge controversy debate among them. If there are any trees or it's rolled I bet it will come off.

agreed. we had a big discussion with them last year about the wing. they claimed it gave some ridiculous amount of down force, i don't remember the exact number they gave. i bet at 35 mph the only down force it provides is from the weight of the stupid thing, not it's aerodynamic qualities. it seemed to be a cheap way around the changing your car rule, and i'm happy to see that they enforced the rule on them this year.

Having been a member on a team that did well with wings in FSAE I can tell you a few things.
1) That wing is way too small.
2) If it was big enough there wouldn't be enough HP to push it through the the air.
3) :shaking:
4) The air that does get to it would be very "dirty" because of the flat plate firewall and roll hoop.
5) :shaking:
6) :shaking: :shaking: :shaking:

5) :shaking:
6) :shaking: :shaking: :shaking:

come on, they did "testing"....:shaking: strangely, they never went into detail about the testing phase of the wing...i'm thinking that they claimed something like 100 lbs of down force at 40 mph (even if the car was capable of that speed which i doubt it was, it certainly never hit that on the course)

and for those advocating light weight...last year we ran a honda civic transaxle with a 5" nascar style clutch:flipoff2:. on the hill climb, we stalled it, so the driver threw it in reverse, bump started it, and drove right up. people were trying to figure how what happened. we went with a cvt this year though, but we still have a gear box and reverse.

7) Even if it did work what would it matter on something that is power limited not traction limited.:gary:

7) Even if it did work what would it matter on something that is power limited not traction limited.:gary:

It isn't for mechanical grip, it's for pitch trim. Baja cars have a tendency to drastically nose forward in jumping, so they use the wing as a fixed elevator to nose the car up.

Unfortunately, no matter how many tens of hours they spent making it and tens of minutes they spent testing it, it doesn't work nearly as well as they say it does. It makes for a cool design item, as long as they don't try to sell it for more than 30 seconds, which is the time it takes for them to run out of justification and the numbers start falling apart. Further, it has now cost them endurance positions in South Dakota (which also cost them a podium in the overall) and Tennessee, as well as a water run in Tennessee (it seems that when the wind blows while they are in the water, they tend to spin in circles), and a ton of work time spent taking it on and off.

It's odd, being one of the best maneuvering teams, second only to my own ego and team, you would think they would know a thing or two about tuning those 5 way shocks of theirs. Poor little rebound valve, always the forgotten child...

Also, their penalty came from failing to pass tech on the first day. Everyone who had not passed tech by 5 on Thursday was gifted with a 50 point deficit, 20 teams total (not including teams who didn't pass tech at all). However, had they been hit with a top 10 reduction (which should have actually gone to TTU #32), it would have been because their largest design change scheduled for this car....wasn't actually on the car. They spent the 3 days before comp cutting off the tranny mounts and swingarm, after learning they weren't going to get their new custom gearbox in on time. They welded in last years system in a parking lot.

The stupid ass wing is just a band aid for bad suspension design, shock tuning and weight distribution. Our cars (UMD-CP) fly great in the air.

I dont think that you can say USF has a bad suspension set-up. They have one of the best handling cars out there.
I think their car is very cool. Why does everyone think they should not be able to run the wing. You guys all think that it hurts them, so if it is "hurting" them so much why not let them keep running it and have it continue to "hurt" them.

Pitch trim is exactly why they use it. Simple dynamics will show you that as soon as the front wheels leave the ground, the car will begin to nose over. Depending on the individual jump, it can nose over a lot (even leading to a roll over) or hardly at all. The wing serves two purposes. First, the down force it creates pushes the rear end down as soon as it leaves the ground. Secondly, the drag force creates a moment about the CG which also helps to rotate the car. As soon as wheels are airborn, suspension tuning is null and void. As for donwforce numbers, 100 pounds at 40 mph is plausible.

As for the firewall drag, I agree. I don't see how they can get 40 mph on dirt (I've been about 45 on asphalt with no firewall). BUT, if any team could go that fast, I'd say it would be them. I didn't really get a chance to look at most of the cars, but they have to have one of the most efficient drive trains around. If you look, you'll also notice the wing is placed well above the firewall just for the purpose of getting it out of the dirty air.

They also had their new transmission installed, it was the CNC'd case that they didn't get done in time.

I really don't see why you guys are hating on them so much. If this is how people react to a wing, you guys are going to have a damn heart attack if you see our car. They are trying something different, thinking outside of the box. Isn't that what this stupid competition is all about?

I dont think that you can say USF has a bad suspension set-up. They have one of the best handling cars out there.
I think their car is very cool. Why does everyone think they should not be able to run the wing. You guys all think that it hurts them, so if it is "hurting" them so much why not let them keep running it and have it continue to "hurt" them.

when i saw their car last year, it wasn't that it had good handling or suspension, it just didn't weigh anything. in fact, the thing bounced around the course in a rather uncontrolled fashion with the solid rear axle. i don't think the wing hurts them, it's just ugly and at most balances the car a bit which they could do with some weights.


I really don't see why you guys are hating on them so much. If this is how people react to a wing, you guys are going to have a damn heart attack if you see our car. They are trying something different, thinking outside of the box. Isn't that what this stupid competition is all about?

sometimes thinking outside the box is stupid, ugly, and pointless. you can see that by looking at 1/2 the cars which are cobbled together turds.

from everything i heard and saw, the wing was added as a design change because nothing else on the car changed and they had to make it look different. they never justified any of the claims they made about it with real testing data.

as well as a water run in Tennessee (it seems that when the wind blows while they are in the water, they tend to spin in circles)

Now thats funny :laughing::laughing:

As soon as wheels are airborn, suspension tuning is null and void. As for donwforce numbers, 100 pounds at 40 mph is plausible.

You can still design your CG and shocks so it will fly straight, we do. And your never jumping at 40mph in the competition. No one is running 40mph.


I really don't see why you guys are hating on them so much. If this is how people react to a wing, you guys are going to have a damn heart attack if you see our car. They are trying something different, thinking outside of the box. Isn't that what this stupid competition is all about?

My beef with it is they used it for their significant redesign last year, thats BS. Second beef with it is that once it was hanging off and they were allowed to tape it to the roof and continue. Thats not what the rules require and thats not what they were told they had to do if they ran it. They can run the dumb thing, no problems with that I still think it's gay.

My beef with it is they used it for their significant redesign last year, thats BS.

that's the problem i have as well. and this year what was the major design change? they ended up putting the old gear box back in it. are they going to montreal? i'll have to take a look at it there i suppose.

We spent a couple hours talking Friday night into Saturday at competition. It is a completely different transmission from last year (6-speed instead of 5-speed w/ reverse). The only difference between what they showed up with and what their design report said is that they weren't able to get the custom case manufactured. It's also direct drive from the engine into the clutch, rather than belt drive as in previous years. The story we heard from them is they got penalized because they never got the re-design paper turned in.

Since our team is still bunch of novices at this stuff, can anyone explain to me how shock tuning affects how a car behaves when it's airborne? I still can't picture how changing your shock valving keeps the car from nosing over.

Since our team is still bunch of novices at this stuff, can anyone explain to me how shock tuning affects how a car behaves when it's airborne? I still can't picture how changing your shock valving keeps the car from nosing over.

think about how the rear shocks / springs act as the vehicle leaves the ground...

think about how the rate at which the rear shocks are allowed to unload / extend would effect the 'push' that the rear end has as it hits the 'jump'...

think about how you control both the rate of extension and the rate of compression...


as for CSUS's car...
we found that a 5" scrub radius on the front end makes for decent steering feel, and aligns the front u-joints under the ball joints, but makes turning with a front locker REALLY hard...

we played with the final drive and ran a 6.5sec 150' and a 4.95sec 100' (stopwatches...) time to get into CVT tuning and get it into the 5's... (yes, we did use the tinytach and set the governor right)

our top speed seems a little low at a GPS accounted for 22.3mph, but we're going to keep messing with the final drive and see if we cant leg it out a little more...

anyone know if the acceleration test at Ill will be 100' or 150'? either way, we're WAY better than last years showing at SDSM&T for 9something :D

I'll be at Peoria this year to watch some of the comp. Worked with the local college on their chassis the last two years. Their car this year is freaking sweet as hell.

I'll be at Peoria this year to watch some of the comp. Worked with the local college on their chassis the last two years. Their car this year is freaking sweet as hell.

what was your involvement with their chassis?

can anyone explain to me how shock tuning affects how a car behaves when it's airborne? I still can't picture how changing your shock valving keeps the car from nosing over.

So what happens when you go over a jump? The front starts to dive and dives faster then what the rear can, correct. So you tune the shocks to cause the front end to pop up a bit higher and causes the front wheels to be closer to the height of the rear wheels as the car finishes the jump.


anyone know if the acceleration test at Ill will be 100' or 150'? either way, we're WAY better than last years showing at SDSM&T for 9something :D

Should be 150'.

There is no way a wing can add that much help during flight. To back up Weasel's comments, I know they have done a ton of tuning and experimenting with shocks to get a better balance on the car. When I was there, we were jumping the car all the time without too many issues except for an over zelous driver! I think Jason learned from that one. It would be funny to see a lot of trees on the course and the wing getting hung up and pulling the tires off of the groun. :flipoff2:

Good luck Weasel.

just an example of how our cars fly, notice the lack of a wing?

http://i112.photobucket.com/albums/n199/Roktgr/Baja/Belle%20Fouche/IMGP0846.jpg

I miss doing the mini baja in college.. the one part of college i enjoyed besides wheeling after classes.. our car was junk though lol

That is your car jumping without the firewall. What about some pics of it jumping during comp. with the firewall.

My beef with it is they used it for their significant redesign last year, thats BS. Second beef with it is that once it was hanging off and they were allowed to tape it to the roof and continue. Thats not what the rules require and thats not what they were told they had to do if they ran it. They can run the dumb thing, no problems with that I still think it's gay.

That is what I have against it as well, if you are a top 10 team then you should know damn well how to improve your car, not skating by the rules with a wing.

I was also pretty pissed that we got dq'd for writing down the wrong shade of gray of our spring, when their wing was scattered all over the course.

Lets get this back on track...
Here is some pics of testing
http://img255.imageshack.us/img255/3040/img1208ag9.jpg (http://imageshack.us)

http://img410.imageshack.us/img410/7301/img1318pm6.jpg (http://imageshack.us)


We like low tire pressures, and we hit stuff way too hard, so we have been bending the shit out of our wheels, so we rockringed them.
http://img120.imageshack.us/img120/3230/img0016iv8.jpg (http://imageshack.us)

I'm glad you already decided on your own that you are going to be P.M. next year, Tom :P

One last comment on the wing. If they did it just to pass the design modification rule, good for them. They aparently thought they had a good design and the wing alleviated them having to change anything they didn't see fit to while still meeting the rules. Racing is all about finding loopholes to get around restrictions. That's why sanctioning bodies revise their rules yearly. It is exactly these restrictions that force us engineers to think creatively and come up with new ideas that eventually work their way into production vehicles (though I realize adding a wing to simply say the design changed doesn't really apply to here). If they did it because they actually think aero can play a role in the design of our cars, kudos as well.

Jeepermat, why do you run low tire pressures (except for rock crawling)? If anything, we usually run a little above the recommended pressure.

We run about 3psi, it sticks.
Most big quads run right about there too.

Jeepermat, why do you run low tire pressures (except for rock crawling)? If anything, we usually run a little above the recommended pressure.

Softer tire absorbs more impact, less transmit through the rest of the car. We run under max pressure as well.

And the firewall does not change how our cars jump. After competition last year, we did this all day long.

http://i112.photobucket.com/albums/n199/Roktgr/Baja/100_1172.jpg

I try to get the smallest tires I can, then bump up the air pressure to decrease the contact patch (and rolling resistance). I get small tires to try and reduce unsprung weight and inertia. Of course, it's all a toss-up when you go to the sand dunes because skinny tires like to sink. What wheels are you guys running?

I'm glad you already decided on your own that you are going to be P.M. next year, Tom :P

One last comment on the wing. If they did it just to pass the design modification rule, good for them. They aparently thought they had a good design and the wing alleviated them having to change anything they didn't see fit to while still meeting the rules. Racing is all about finding loopholes to get around restrictions. That's why sanctioning bodies revise their rules yearly. It is exactly these restrictions that force us engineers to think creatively and come up with new ideas that eventually work their way into production vehicles (though I realize adding a wing to simply say the design changed doesn't really apply to here). If they did it because they actually think aero can play a role in the design of our cars, kudos as well.

Jeepermat, why do you run low tire pressures (except for rock crawling)? If anything, we usually run a little above the recommended pressure.

If they did use the wing as a design modification, then it should be required to run the whole event in the configuration it was intended. It is just like the promod bumper rule where guys were making consumable bumpers that would get smashed on the first course and then not have to run them. I don't see how the wing can play into the sales presentation either. Just my $.02 from a former member.

Great pics of the jumps Weasel. I miss doing that and watching everyone else do it too. Makes me want to make another one.

I try to get the smallest tires I can, then bump up the air pressure to decrease the contact patch (and rolling resistance). I get small tires to try and reduce unsprung weight and inertia. Of course, it's all a toss-up when you go to the sand dunes because skinny tires like to sink. What wheels are you guys running?

Depends on the course and what you typically drive in. Motorcross style course, smaller tires would be fine. Bombing through the super rough stuff, large as you can justify given the weight and intertia. Also with the higher pressures you don't get as much grip and the tires tend to bounce off obstacles.

what was your involvement with their chassis?

My "involvement" was showing them how to use the tools to build with real tools instead of just cutting and splicing every part. They did the work, thanks anyway.

My "involvement" was showing them how to use the tools to build with real tools instead of just cutting and splicing every part. They did the work, thanks anyway.

I don't think that was personal comment, that just something else that is watch closely. That also get people pissed off and teams have tried it before.

My "involvement" was showing them how to use the tools to build with real tools instead of just cutting and splicing every part. They did the work, thanks anyway.

I didn't take it personally towards me, the question was clearly phrased as an ammo for an attack against the team, that had to be shot down before it even gets started. I didn't build or design their chassis, they know the rules very well and are well with in them without using any loop holes.

no worries man - props to teaching people how to use tools... Ive had to figure things out the hard expensive way, and would have appreciated someone helping me out when I was starting out...

That and if me and everyone else here is spending countless hours in a cramped, under equipped shop making an out of square chassis despite our best attempts, i just wanted to make sure that your team was too :D

no intended malice - just wanted to make sure everyone was playing by the rules...

That and if me and everyone else here is spending countless hours in a cramped, under equipped shop making an out of square chassis despite our best attempts, i just wanted to make sure that your team was too :D



Wow, sounds all too familiar :laughing:

no worries man - props to teaching people how to use tools... Ive had to figure things out the hard expensive way, and would have appreciated someone helping me out when I was starting out...

That and if me and everyone else here is spending countless hours in a cramped, under equipped shop making an out of square chassis despite our best attempts, i just wanted to make sure that your team was too :D

no intended malice - just wanted to make sure everyone was playing by the rules...

http://img221.imageshack.us/img221/11/dsc0011yb7.jpg (http://imageshack.us)
Sucks to be you guys :flipoff2: We also have a big ass lounge/computer lab next door with couches (that I have often slept on) and keys to a bad ass machine shop.

this is at one of its messier times (the reason I took the picture), but we share this shop / storage space wight FSAE on campus... :eek:

http://www.opiebennett.com/MiniBaja/CSUSMiniBaja5908/stp82875.jpg

and other than limited acess to the machine shop, we buit our chassis and all our other parts with 'garage fabricator' tooling and equipment...
Chop Saw
Sawzall
Grinder
Drill
110 Mig welder

thats about it.... :flipoff2:

here's our shops. i didn't include the other EDM machines, or our manual machine shop.:flipoff2:

Dang thats a nice clean shop, what kind of school is that? Our is about twice a big as the first shop pictures. Our CNC lab is sorta small but we have three CNC mills and one lathe, one of the mills is also a manual. Just got a new manual lathe so we have two now, couple bandsaws, and other stuff. Shop is shared with FSAE, Aero, UAV, Snowmobile, and HPV but FSAE and Baja claim most of the floor space, four of each cars.

For cool no body else has equipment we have one of the largest or if not the largest Friction Stir Welder in the US, also have a laser deposition machine, which FSAE use regularly.

We've got a friction stir as well and I think a laser deposition, too. Problem with our school is that everything revolves around research, so we still end up with shitty equipment for the design teams to use. Sure, they bought us a brand new $25,000 lathe. BUT, it's Chinese; so it spends at least 50% of the time broken. The folks in charge seem to think old stuff is crap, so they are trying to get rid of the few Bridgeports, Cincinattis, and Southbends we have left. I really think the tech schools have a big advantage over the smaller engineering schools, especially when your department is run by a bunch of guys who know nothing about making stuff (you should see the shit some of these professors ask our machinists to make). Oh, and we have to share our shop with the Solar Car team. Talk about the biggest bunch of 'tards you've ever seen. One of them is going to die this summer. I can see it coming.

here's our shops. i didn't include the other EDM machines, or our manual machine shop.:flipoff2:

your shop is an "over the top" vision i have for our shop:D where are you?

Pennsylvania College of Technology

We have a manual shop that is the same size as the CNC shop. the first and fourth pictures are each half of the CNC shop. we also have robotic welders, cnc plasma cutter, sodick die sinker, a bunch of haas tool room lathes and mills, about 20 manual lathes, 20 manual mills, couple cylindrical grinders, 15 surface grinders, a thread grinder, two screw machines...etc. it's a pretty nice place.

LOL cramped is right. I gave them an extra table top I had, I have no idea how they have that thing in their shop! They have Baja, FSAE and clean snowmobile in the same space that is just slightly bigger than the one XJ ranger posted, but they have some storage elsewhere. They have a lathe and a Protools Bender in there but if they want a mill they have to go up to the small machine shop. That's why they came to my place to get the bulk of the chassis work done, better tools and lots more space to work with.

I used to be on the team btw. Also I'm moving to PA and going to that school just to play with those toys. That shop is 10 times nicer than all 6 of the machine shops here in town! Although my shop is nicer than theirs too...

Who says A-arms cant flex? :smokin:

Taken Sunday....
http://www.opiebennett.com/MiniBaja/CSUSMiniBaja51408/stp82926.jpg

Taken an hour ago -
http://www.opiebennett.com/MiniBaja/CSUSMiniBaja51408/stp82946.jpg

Looks good You guys liking the a-arms over the front axle?

Looks good You guys liking the a-arms over the front axle?

things we've learned so far:
steering in high travel, short A-arm suspension, puts A LOT of side load on steering racks - especially when crawling, and turned into bindy stuff...

Locked front axles and 5" of scrub radius make turning REALLY hard, and puts A LOT of load on the A-arms and steering arms, and the rack...

Broken 1 rack, broken 1 rack mount, broken 1 steering arm... stronger versions of all 3 are now installed... Sunday will prove them...

Im likening that the A-arms are lighter, but not really noticing the other benefits of independent suspension - the better handling and all that... I think that I am so used to the way a soild axle feels at speed and crawling, that A-arms feel not much different...
The one big thing that I do notice is the lack of inirtia in the front end components, the suspension reacts faster in terms of dropping out when airborne and stuffing - I do like that.
Maybe its because I spent so much time and $$$ on my jeep getting the front suspension how I like it, and this is rev 1 here, but they feel about the same...

We had a long travel suspension in Tennessee. From what I can tell, we were actually running more angularity than a Class 1 truck. Given those angles and the small dimensions of everything on a Baja car, we ran into some tough problems, especially with steering. If we do A-arms again (which won't be in the forseeable future) I'd find a way to narrow up the chassis and increase the track at the expense of not being able to go down some ATV trails. Twin trailing arms is where it's at, though.

Hom much travel?
We have 15" in the front with A-arms, no bump steer, or any other problems. Our front suspension box is only 2" wide though.

We had 11 or 12. So I guiess it was more of a "high angularity" suspension rather than a true long travel. But I think that's pretty good considering we had 8 last year with factory ATV arms. We used the same mounting points and only increased the track 2 inches on each side this year. Our problems stemmed from using an old frame as the starting point and trying to fit the components in the given space so they worked throughout the whole range of motion. I think the lower mounting points are 15" apart and the uppers are 18". Track width is up to about 52", campared to 48" previously. We had a clutch pedal last year, which required the bigger pedal box.

How do you post pictures? I'd like to stick one up showing the full articulation.

got our body panels back and they are pimp. :smoking: Might be able to snag a pic sometime, look for them at comp.

We have run a trailing arm setup, I like the A-arms better. RC move in a straight line, easy to control camber, make camber changes, easier to build, RC motion matches the front so even yaw in corners.

You guys have a narrow car, our track is about 64". We don't have any angularity problems, have in the past but it's all been worked out.

Pictures link from a photosite or buy a red star.

We were 64" our first year ('06). Combine that with a 7 foot wheelbase, spool, IRS, and 754 pound dry weight and you get a car that doesn't exactly turn too well. 48 inches was what we ended up with last year after slapping the ATV control arms on. I drove it a lot over the summer and it went down ATV trails without too many problems. Also fits in the back of my motorcycle trailer nice, too. We'll probably go wider next year to get more rear travel since our CV joints are maxed out right now.

I like trailing arms because of the ride and impact absorption, which reduces the loads on the entire suspension and frame. Yeah, RC geometry sucks and I didn't bother with trying to figure out anti-dive. This is just a trial run to see whether it is worth putting more effort in to next year. I figure desert racers, dune buggies, and VWs use them so they can't be all bad.

You guys have a narrow car, our track is about 64".




Holy shit! Ours is 46"

To post pictures host them on a site like this
http://imageshack.us/

http://img524.imageshack.us/img524/5021/img1098cq2.th.jpg (http://img524.imageshack.us/my.php?image=img1098cq2.jpg)

http://img524.imageshack.us/img524/5021/img1098cq2.th.jpg (http://img524.imageshack.us/my.php?image=img1098cq2.jpg)

Nice looking geometry - the shock being that far inboard scares me from a bending loading standpoint, but the scrub radius looks good, the angles dont look bad, and decent articulation.

What size tube is that? looks like 1.5" OD :eek:

Uppers are 1.5" x 0.125" 6061-T6 box tube. The lowers are 1 inch. I went with box instead of round because it is stronger in bending. The suspension judge really liked it.

We (I) kinda screwed up the math on shock mounting. 3" of shock travel and 12" of wheel travel means you mount the shock 1/4 of the way down the arm, right? Not really. I also forgot that the bumpstops give another inch of shock travel. We're going to get all that fixed for Illinois on the new arms. If we do A-arms again I'd like to spend more time actually getting all the geometry right so nothing binds and jigging it up rather than fabbing by eye. We can get about 70 degrees of motion with the monoballs and misalignment spacers, so that comes in handy. Aluminum is cool and I'm sure it can save a good bit of weight if you do it right, but we didn't see too much (not that 2 pounds per side is insignificant). Still, we only snapped one weld and they worked fine after I patched them up. So I guess it isn't too bad for a second attempt at A-arms.

So I'm guesing you didn't heat treat them after welding?

One of the reason the only aluminum we use is machined billet. They have started welding some small aluminum stuff and I'm somewhat concerned about their heat treatment they plan on doing. 4130 is used for nearly everything. I would like to see more carbon used.

One of the reason the only aluminum we use is machined billet. They have started welding some small aluminum stuff and I'm somewhat concerned about their heat treatment they plan on doing. 4130 is used for nearly everything. I would like to see more carbon used.

personally - id like to see less machined billet aluminum...

more fabricated pieces - like our uprights...

Id like to see cast aluminum...

Id like to see the cars go towards that design goal of 'production'...

look at all the ATV and Side By Sides OEM's parts - cast, fabricated steel, injection molding...

Casting isnt all that hard, and if you're going to be making 2000 cars - billet AL adds up REALLY fast...

I know that these parts are heavier, and weight kills in every event except the rock crawl, and the judges dont really have enough pull in the design judging to make up for the time and effort, and the cost report is about the same, but a lot of the cars I looked at last year would RIPPED apart by any production company, and would cost 1/3 as much to make, weigh 12lbs more, and function exactly the same...

Carbon Fiber shouldn't be anywhere on any of these cars IMO...

Walk into the local auto parts store - look at the mini baja sized go-karts, look at their engines, look exactly the same, seat two, complete...
out the door price - $1200...

Id bet the cheapest cost report is upwards of $5000 if they're actually using retail prices like you're supposed to...

We heat treated them. The problem was in our notching the arms to fit the bearing housings. I had to fill some pretty big gaps and there were some other spots that were super thin. Basically, it came down to a poor welding job on joints I should never have touched in the first place. The actual weld snapped right down the middle of the bead. We rewelded them and added some gussets that wrapped from the housing to each leg of the control arm. I'm surprised they didn't fail afterward since we didn't have a way to heat treat them in Cookeville. All of our other aluminum has held up fine. My big concern is fatigue failure. Aluminum obviously works fine on street cars, but I guess only time will tell if it can handle off-road abuse.

We are lucky to have a Metallurgical Engineering program and a campus foundry. I'd like to start casting next year. Probably begin with our transmission case and progressively work toward more structural components.

I think carbon would be cool, especially as a true composite in combination with other engineering materials. Anybody seen the carbon-wrapped aluminum trailing arms for snowmobiles? Those carbon-impregnated plastic ATV wheels are pretty trick, too. I've heard both good and bad about them.

I guess it comes down to a question of what the folks at SAE really want us to build. More and more, I get the vibe that they expect a "pre-production vehicle" rather than a true prototype. Most prototypes, even from the major auto makers, are complete hack jobs (the Dodge Challenger show car was a Magnum they took a blow torch to). Afterall, this is an exercise in design, not fabrication abilities.

Having gone from a school team to a lab where we build most of the prototype machines, I can tell you that machining a part first to verify the concept is a lot less expensive than making the molds and casting parts. If you look at this competition as a engineering review at a company where you are trying to get the ok to manufacture your product, you are going to put your effort into making the product function correctly and then after approval, work on the manufacturing and cost reductions. If I remember correctly, you could machine a part for the comp but say you were going to cast it in the report. Is this still correct?

We used to really push that but it never seemed to have much effect, then we decided to change our market, we are selling a high end performance vehicle, not a go-cart you would buy in a hardware store. Obviously engine aside we would compete against the top end of the four wheeled vehicles.

Instead of casting a part we have been optimizing parts, which is a ton of design work even for CNC aluminum parts. We look at it as a design competition not a manufacturing or production comp.

Id like to see the cars go towards that design goal of 'production'...

look at all the ATV and Side By Sides OEM's parts - cast, fabricated steel, injection molding...

unfortunately, it's like nascar. eventually there are no off the shelf items left, and people have given up on the spirit of the competition just to win. i have seen very few cars built with production in mind.

people have given up on the spirit of the competition

The object of the competition is to provide SAE student members with a challenging project that involves the planning and manufacturing tasks found when introducing a new product to the consumer industrial market. Teams compete against one another to have their design accepted for manufacture by a fictitious firm. Students must function as a team to not only design, build, test, promote, and race a vehicle....

Everyone idea of what the above means is different but there are no set standards or guidelines.

some testing sunday -

nice shots of it fully assembled (minus rules stuff like roll bar padding and crap)
http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83139.jpg

We set up an endurance race course and ran the car for a good 3-4hours with different drivers...
http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83169.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83170.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83174.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83185.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83192.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83201.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83207.jpg

Our faculty Advisor while we were testing -
http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83232.jpg

weak point finding -
http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83235.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83238.jpg

already fixed that, and modified the other side to strengthen it.

approach angle testing -
http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83250.jpg

is this thing on?

or is everyone spending too much time working on junk and doesn't have computer time anymore?

is this thing on?

or is everyone spending too much time working on junk and doesn't have computer time anymore?

Pictures of your rig look good, any videos?:grinpimp:

Pictures of your rig look good, any videos?:grinpimp:

sure...

http://opiebennett.com/MiniBaja/CSUSMiniBaja51808/stp83200.jpg

http://video.google.com/videoplay?docid=8933124186153614728&hl=en

http://video.google.com/videoplay?docid=3230259014788916580&hl=en

http://video.google.com/videoplay?docid=-6580710210570473606&hl=en

I really liked this one -
http://video.google.com/videoplay?docid=8057437295616239372&hl=en

I am amazed how well that thing handles. Gut reaction tells me it should tip over. Looks like it scoots pretty good, too. Any idea of the top speed?

I am amazed how well that thing handles. Gut reaction tells me it should tip over. Looks like it scoots pretty good, too. Any idea of the top speed?

30mph on the strap
75mph on the trailer

GPS tracked 22.4mph top speed with a governor set at 3800rpm and idle set at 1500rpm, and an otherwise 'as delivered' briggs motor...

probably go 29mph on the bottle!

looks good, i've been way to busy with work and research to get up to the shop must the past week. I know both cars are up and running, everything is tuned up and set to go. Panels are going on soon as the final magor driving is completed.

Maybe get somepics or soemthing this weekend otherwise look for us in IL and say hi. I'll be the short one running aroun with the South Dakota group.

I was in the mini baja in troy ohio in 03, jesus, where has the time gone.

So how did everyone make out? I'm working on getting my pics and vids up. Only a few good ones due to the crappy layout of the course. I didn't get around to meet many people but did get to talk to XJ_Ranger and the Sac crew. We did decently for this year, abit disapointing as we were close to winning the entire event one and two but the crappy weather and a few breaks set us back a bit.

Overall 4th and 6th. 1st in Endurance, 2nd Hillclimb, 4th in design. Pretty much the best year we have had yet.

hey xj ranger,

your car is awesome, i saw you guys kick the conquer the hillclimb with ease, how did you guys do on the rock crawl, i really wanted to see your on that nasty rock crawl, and by the the way im from wilkes U., and we were behind you in the tech. insp. line. our whole team(team of 3) thought your car was awesome.

also, does anybody know where the proffesional photographers photos will be posted?

Weasel, congrats on the win in endurance! That was one hell of a showing.

I came down Sat to hang out with the team. Their captin made a bonehead move to save 2 lbs and took out the low range in the t-case, so the car was geared way to high. after some minor mechanical fixes they ended up getting DQed in the endurance for not being able to make it up the hills. The prototype tranny they were testing worked great for the little they got to run the car, but just not low enough reduction. They were way ahead a couple of months ago, I'm not sure why they didn't get to test the car at all.:shaking:

the rock crawl was weak. Not even a decent challege for their rig.

Did they let you guys run it backwards?

We had the fastest time through the crawl by 1.2 something seconds and that was with breaking a steering arm. But our driver brushed two "flags" even though we were told when we started the course that the flag only counted if you drove over them. And flags are gay. Oh well.

Weasel, congrats on the win in endurance! That was one hell of a showing.

I came down Sat to hang out with the team. Their captin made a bonehead move to save 2 lbs and took out the low range in the t-case, so the car was geared way to high. after some minor mechanical fixes they ended up getting DQed in the endurance for not being able to make it up the hills. The prototype tranny they were testing worked great for the little they got to run the car, but just not low enough reduction. They were way ahead a couple of months ago, I'm not sure why they didn't get to test the car at all.:shaking:

Thanks, it's been a long time, 5+ years.

We did pretty well considering where we have come from, 14th overall. I thought the track was pretty good, it definatley weeded them out quickly.
We broke a gear in our case in the 2nd hour, but were able to piece it back together in about 40 minutes and get back in.
SDSM-what did you guys break? I was following you through the rock garden and you just stopped?
Also you rear ended the hell out of our car trying to pass on a yellow, I hope your tire is as fucked as our tow hitch is :flipoff2:
http://img98.imageshack.us/img98/1785/dsc0065zd1.jpg (http://imageshack.us)
http://img155.imageshack.us/img155/8509/dsc0091tq6.jpg (http://imageshack.us)

Opps sorry about that, was it the 7 car or the 117 car. I think the 117 car lost most of it's brakes at some point.

Which rock garden? The actual garden or the stadium side rock pile? We broke part of our driveline early on but I don't think we broke anything in the rockcrawl section.

Stadium side rock garden, I was following you at a pretty good pace (the 7 car), and it just stopped, and had to be pushed off course.

Congrats SDSM&T. It is awesome to see where the team has come in a few years.

We pretty much sucked ass. Our cool car never got finished (lack of dedication from much of our team along with other things). The old car somehow took a step backward from last year. Fixing all of our weak points we found in Tennessee opened up a whole other can of worms, many of which I couldn't get fixed properly in time for Illinois. Dynamic events were pretty crappy, but at least we finished them all this time. We twisted a U-joint in our main driveshaft about 30 minutes into endurance and it actually bent the output shaft on the trans, which put us out.

We are looking at WAY better drivetrain efficiency and loosing about 150 pounds for next year. What should have been car 88 is going to be our testbed for the new drivetrain since it already rolls; so, we should be testing by September. Maybe next year we can actually stick to the KISS method like the good teams do and get out of the bottom 50% for once.

Stadium side rock garden, I was following you at a pretty good pace (the 7 car), and it just stopped, and had to be pushed off course.

Yep thats where our first driveline break was.

karman1970,

Sorry about the bad breaks. Testing is really key.

Yeah, we learned that for sure. Testing in parking lots and such can't really prepare you for some of the stuff they come up with at comp, either.

Pennsylvania College of Technology

We have a manual shop that is the same size as the CNC shop. the first and fourth pictures are each half of the CNC shop. we also have robotic welders, cnc plasma cutter, sodick die sinker, a bunch of haas tool room lathes and mills, about 20 manual lathes, 20 manual mills, couple cylindrical grinders, 15 surface grinders, a thread grinder, two screw machines...etc. it's a pretty nice place.

http://i151.photobucket.com/albums/s130/madman42/shop2.jpg
http://i151.photobucket.com/albums/s130/madman42/window.jpg

Auburn had an up and down race. Our first day was one of the better static days we've had, finishing 3rd overall for the day. We were just 2 points out of design finals, which was good, and bad (we really wanted to make it, we've never made it and have been one place out 4 times now). We also proved that you can top 10 in cost with a 10k car, you just have to be completely honest about every dollar of that 10k (we were 3rd at East, so it wasn't a fluke).

Our second day was pretty standard. We didn't excel in any one event, but we managed to put down solid runs in everything before the rain came. I was kind of dissapointed in our 5th in manu., the car setup was completely wrong, and that's one of my lowest finishes in that event. After the rain came, we had run at least one of everything, with 2 manu runs, so we pretty much packed it up and called it a day, since the events were trashed. We left still in 3rd place overall (although the 2 above us changed).

The endurance race sucked. Hard. We gridded 11th, pretty normal, and the car seemed ok to run. After the race started, I ran for 56 seconds, hit the first set of cross trenches, and then...the engine turned off. We have no idea why, but it certainly wasn't restarting. So, 1 hour later, after a swap, my brother hopped in and managed to run a very fast 45 mins, with a fast lap of 4:02, and then...the fucking engine turned off. Since that was our spare, we had to just start replacing everything we could. 5 carbs, 2 spark plugs, a new magneto, and a trip to briggs later, we managed to run the last 20 minutes, and ended up finishing 44th (48th, actually, but the four DQs pushed us up).

Overall, 21st. Freaking Briggs.

http://photos-h.ak.facebook.com/photos-ak-sf2p/v250/125/81/7003856/n7003856_37796287_5668.jpg

no chance it was kill switch wiring? :flipoff2:

The motors this year sucked balls. Our problems stemmed from a non-functional float. Had to replace the carb with our '06 one, but not before shearing the flywheel key trying to restart it and finding it had managed to hydrolock itself at WOT turning 3800 rpm (which didn't evidence itself until brake check in TN when the flywheel spun on the crank). The fan shroud and starter housing on our other new engine were so bashed when we recieved it that it won't even turn over. Since we aren't eligable for a freebie next year, I think I'm going to rebuild our '07 engine. Ran like a champ all summer.

And the Briggs guys are retards. Took them almost an hour in TN to diagnose the problem and then they didn't even have any tools (or spare crank keys) to work on it.

no chance it was kill switch wiring? :flipoff2:

What's funny is they actually asked us if a wire was disconnected. You'd think they would actually know how the electrical system on their own engine works.

as for CSUS:

The car was significantly better performing this year than last - we shaved 1.5 seconds off our 150' time - even doing this years acceleration RIGHT after the first rain...

The rock crawl was more of an agility 2 - I ran the event twice as the driver, never looked at my spotter once... I ran it open / open in high range the first time and logged like a 32 second run and didnt hit a single flag... the 2nd run was after the 2nd rain, and was more of just a fawk around and see if we can still make it - ran open front, locked rear, high range - logged a 40 second run with like 2 flags... took 16th in an event we should have had first in... a TON of teams came up and said they thought the 'crawl' was a joke and they knew that because their car finished it... I say it is what it is... I think the rain helped our score on that big time by keeping teams from finishing...

I feel kinda jipped that I NEVER had to use reverse AT ALL during the crawl...

SDSM&T did a much better, more challenging crawl, but whatever...

We were probably one of the only teams to log a faster agility time after the rain (allowing the front end to slide more in the mud acutally made our car turn tighter [4wd push and all]) - and Ruben drove the SHIT outta our car - coming in only 12 seconds behind the fastest car - with double the weight...

Hill climb - heavy car = bad time... but the 4wd helped us do it - we did it both runs after the first rain...

We were really impressed with the car after the first day of the dynamic events - no issues with the car at all, performed as well as we'd expected (minus the mud effecting our acceleration score by about .6 seconds)

We were 27th place headed into the endurance race - putting us at the low end of the major Baja players list, but still up there, and we were really excited about that...

The endurance race really effed over our car...

first 3 laps went pretty well, people getting stuck on the hills in front of us caused issues, but other than that - all was good - then on the back half of the course in lap 3, driver Ken noticed a weird noise that was getting worse with speed... as he pulled into the pit, we noticed a bent rod end in the lower A-Arm, and atributed that to the noise (1/2" shank rod end bent like a piece of pipe cleaner). pulled into the paddocs, fixed that, threaded all other rod ends all the way in to minimize their moments, got back into the race with a different driver - Tim. He noticed a 'grinding' noise - the same Ken had heard...
2 laps later, he pitted in and we tried to diagnose the noise...
Couldnt figure it out, so topped off with fuel and sent Ken out again...
1/2 a lap later our ANSI 40 chain let go, and we were towed into the pits...
there we found we'd buckeld a lower a-arm (not broken, but severely yielded), the CV boot that we'd put on our driveshaft had mostly broken away, taking out our driver kill switch wiring, and was making the grinding noise, and broken our chain. material was added to the lower a-arm, CV boot was removed... (more on CV boots later) and wiring was re-made, and a new chain was put together... and back the car went out again...
2 laps later, the chain broke again (lack of lubrication and skipping off the chain tensioner is the likely cause of this) Slapped a new chain in there, and I took off to drive
Sheared the upper A-arm just as our lower had failed in testing... :shaking: bad engineering...

41st overall is better than last year's 67th overall...

next years car is looking to be a 2wd - because this year we never needed:
4wd
low range
reverse

thats like 150 pounds right there - even just eliminating those things from this existing chassis... building a car around not having those things would be even lighter...

oh yeah - and twin I-beam - long travel Ford Ranger style :smokin::smokin::D

CV Boots... CV Boots...
*Controversy* so there were 3 or 4 teams running drive shafts from their transmissions to their rear drive - some were solid axle, some were IRS...
Only 1 team was called out in Tech Inspection and told they needed the .060 steel guards around stuff rotating faster than final drive - we were passed through tech with CV boots on the differential ends of the drive shafts and thats it...
Apparently at Tennessee, there was an all girls team that was FAILED in tech and never got to compete, and had the same guarding as we did, and had passed tech with. The one team at Illinois that was called on the driveshaft guards and forced to do something about them to pass tech, tried to do what we did, and pass, and they were failed... eventually they acquired some 5" Flex exhaust tube to cover their driveshaft, and passed, but someone mentioned to the tech inspectors that CSUS and a few other teams DID NOT have driveshaft guards... so at like 6:30pm Friday night (after the first day of dynamic events) the black flag guy (Mike?, or Mark?) came over and talked with us about this, and tried to get us to guard our driveshaft... I basically told him that I couldn't do it in time for the endurance race, and that the tech inspectors needed to call us on that the first day of tech to give us time to rectify the situation - not hours before the endurance race... he agreed, but asked that we put CV boots on the transmission end of the case as well to prevent fingers from being stuck into the u-joint... we did that, and one of them came apart, and ripped out all our wiring... :shaking:

The shitty part about all of this is that it really discourages trying new things drivetrain and suspension wise if the tech inspectors are going to try and enforce a rule that was not intended to be used on driveshafts that is almost impossible to conform to with a suspension like we had - our driveshaft moves around WAY too much to be guarded...

I talked at length with Mike? Mark? about possibly re-writing the rules to require a driveshaft loop similar to those seen in desert racing and sand rails, (and NHRA 13 second and faster cars) and some sort of protection from getting hands into the u-joints, and he said that was in the works, but people needed to post up on the SAE forum about it, and how it should be done and get interest from non-inspectors... so if you were one of the other teams with a driveshaft, get over there and do it... I will be doing that later tonight...

Im going to upload pictures tonight...

The motors this year sucked balls.

I'll agree to that too - ours showed up with a drain plug cross threaded and tightened all the way down. Had to drill the hole bigger and re-tap it because the threads were so chingered...

something tells me that brigs sends out motors for free that didn't pass QA...

XJ, we had a driveshaft running from the trans to our quickchange (which ended up failing and knocking us out of any sort of contention). They called us on it at TN (even though it met the rules, but since it didn't really move much we were able to just build a box around it.

I'm half tempted to order a half dozen copies of each major internal component and just rebuild the motor using the ones with dimensions I like best.

I think everyone is getting tired of building a car to meet the letter and spirit of the rules, only to show up and be told "oh, we didn't really mean that; this is what we actually wanted." Then, those definitions change for each race.

By the way, your car was pretty sick. That thing would tear some shit up if we had more power. We were a couple spots in front of you for tech (your second time through, I think); the neon green #87 from Missouri.

I'm half tempted to order a half dozen copies of each major internal component and just rebuild the motor using the ones with dimensions I like best.


even though the rules strictly prohibit blueprinting - we had thought about doing basically what you are talking about - ordering a bunch of parts, and using the ones that are *PERFECT* specs rather than *In Tolerance* specs...

By the way, your car was pretty sick. That thing would tear some shit up if we had more power. We were a couple spots in front of you for tech (your second time through, I think); the neon green #87 from Missouri.

Thanks! we spent our share of time working on it. It is always fun to walk around and look at what other cars are doing...

it seems that every car has something special that no one else does - air shifted paddle shifters, cutting brakes, tilt steering wheels, suspension seats, 3 links, and 4 wheel drive :D

uploading competition pics and video now...

That sucks that the 1 thing that should be a constant in all cars craps out on you, why dont they get Honda to get us engines?

Also I agree tech was pretty inconsistent this year, we had to go through twice, the second time around they crossed out items that had already been signed off. I was also told I followed the rules a little too close.

I agree you guys got screwed on the rock crawl, I saw that course and immediatly thought of you guys and how pissed you would be. I guess I liked it better for our car, because we were actually competetive.

Congrats SDSM&T. It is awesome to see where the team has come in a few years.

you'll like this team group shot -
http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83333.jpg

for some reason - everyone liked our shirts...
http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83334.jpg

We were a couple spots in front of you for tech (your second time through, I think); the neon green #87 from Missouri.

I got a shot of your rig in tech -
http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83355.jpg

and a few in the maneuverability i think as well -
http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83558.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83559.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83561.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83562.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83563.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83564.jpg

http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83565.jpg

That sucks that the 1 thing that should be a constant in all cars craps out on you, why dont they get Honda to get us engines?

Also I agree tech was pretty inconsistent this year, we had to go through twice, the second time around they crossed out items that had already been signed off. I was also told I followed the rules a little too close.

I agree you guys got screwed on the rock crawl, I saw that course and immediatly thought of you guys and how pissed you would be. I guess I liked it better for our car, because we were actually competetive.


I graduated from RIT in 02 and was on the team from 98, and Briggs sucked @ss then too. It's too bad to hear they still haven't gotten their chit together yet. One year at Wisconsin we were breaking in a new engine and after about 15 minutes it threw the rod through the block. 5 other teams had the same thing happen and the Briggs guys said it was some disgruntled employee who sabotaged the engines. The experience I had with their engines in Baja is specifically why I WILL NEVER buy Briggs powered equipment.

Honda approached us one year about testing engines for them, as well as a couple other teams, along side with the Briggs engines. They were going to try and make a play for being the engine source, but I think Briggs caught wind of it and managed to keep them out of it somehow. It would have been nice because they had an 8 HP engine that made more power and torque than the 10HP Briggs when set to the same governed speed.


Oh, and if Jason Rounds is still in charge of tech or safety or whatever he's into for SAE now... on behalf of the 98-02 RIT team, sorry! :flipoff2:

Oh, and if Jason Rounds is still in charge of tech or safety or whatever he's into for SAE now... on behalf of the 98-02 RIT team, sorry! :flipoff2:

oh... he is... :shaking:

Oh, and if Jason Rounds is still in charge of tech or safety or whatever he's into for SAE now... on behalf of the 98-02 RIT team, sorry! :flipoff2:

Im not gonna say anything...:evil:

We've never really had an major problems with the Briggs engine. Even with the one we shaved the head on and ran a straight pipe for winter comp . Although it's was not very happy after that trip.

Tech is always a cluster.

Sweet pics, XJ. That was me driving. And that course sucked balls after the rain. I'd guess I picked up close to 50 pounds of mud on the second run.

no chance it was kill switch wiring? :flipoff2:

Got off the phone with Briggs a little while ago - For the first engine, when I hit the cross ties, the pushrod jammed up the intake rocker. The second engine had a split spark plug wire.

That blows. We had the intake rocker completely fall off in '06. You wouldn't think it would be that hard to build a reliable engine. It's not like were running F1, you know.

http://img524.imageshack.us/img524/5021/img1098cq2.th.jpg (http://img524.imageshack.us/my.php?image=img1098cq2.jpg)

Holy Leverage ratio Batman! :eek:

G-

Holy Leverage ratio Batman! :eek:

G-

that's what i thought, but if those are shocks off a quad, look at some of the leverage ratio's on those. some of those rear ends cycle 13+ inches of travel with shocks that have 3 inch strokes.

not quite to those numbers... but i see your point. but those quads aren't going to last a race with shocks that can still control the suspension because they are so hot and over worked.. and most rear ends are all using a linkage design that can control the leverage ratios for different points throughout the travel. but there is hardly any quad that is worth owning that has a levarage ratio greater than 3 to 1.. and just guessing, that picture probably has a 5 to 1.. where as most good set ups are around 2 to 1....

now for just crawling.. they work great.. but for any type of racing in rough terrian.. those shocks would be faded in half a lap, and the car would be all over the place....

G-

It's a 4:1 ratio. With our wheel and spring rates, the suspension doesn't really move too much unless you are getting into some really serious stuff. At which point, you won't really be going that fast. BUT, that suspension is sitting in our scrap pile right now due to other reasons. Spwitched over to a set of +2 Warrior arms and Fox 2.0 pre-runner shocks and Hypercoil springs. If we do A-arms again, I'll propoably copy the dimensions and make them out of lighter material (bottoms are 1" x .120" wall 4130 and the uppers are .083" wall). We probably added 20 pounds by switching from the all aluminum front end to the steel stuff. But, it worked.

Here's a question, guys: how much do your tire and wheel assemblies weigh? Our Dunlops and 8-spoke Maxxis wheels are 21.3 pounds each (7.5 for the wheels, 13.8 for the tires). Anyone significantly lighter?

If y'all can't tell, I'm bored out of my mind waiting for work to start next week.

for the type of speeds you guys are doing.. you can probably get away with doing .083 wall lowers, and .065 uppers using a good seamless 4130 tube. those cars are around 400 lbs right??

g-

You can get away with those wall thicknesses, absolutely.

A good baja car is around 400, but I'd say the average is more towards 500. Anything above 550 is severly overbuilt and has very little chance of a good finish, and anything below 360 is underbuilt in some form, but has a chance of finishing well. Anything under 330 is trash, as proven by Michigan-Ann Arbor, whose 296 lbs car (from their own mouth) twice made design finals, and have failed to place higher than 43rd in Endurance (funny story, in Tennessee they failed to complete a single lap, after their rear tire raced the car down the staircases; the tire won.)

One usually high placing team told me they were running .065" lowers and .049" uppers. Total weight between 340 and 360. They said they design for the tie rods to be the weak point.

Did anyone see how Arizona's car with the twin trailing arms was handling the nasty stuff in Illinois?

http://img357.imageshack.us/img357/392/dsc0283ur1.th.jpg (http://img357.imageshack.us/my.php?image=dsc0283ur1.jpg)

This is one of the reasons I junked the aluminum.

One usually high placing team told me they were running .065" lowers and .049" uppers. Total weight between 340 and 360. They said they design for the tie rods to be the weak point.


Yeah, that's about standard for the better designs. I've seen lowers as thin as .035 that have finished races.

Was this LeTourneau?

Nope, USF. But Letourneau did kick some ass. I kept expecting to see them get towed in every lap, but they just kept going and going.

Here's a question, guys: how much do your tire and wheel assemblies weigh? Our Dunlops and 8-spoke Maxxis wheels are 21.3 pounds each (7.5 for the wheels, 13.8 for the tires). Anyone significantly lighter?


What size of tires? Wheels seem heavy.

for the type of speeds you guys are doing.. you can probably get away with doing .083 wall lowers, and .065 uppers using a good seamless 4130 tube. those cars are around 400 lbs right??

g-

You can go thinner. On both the upper and lowers.

You can get away with those wall thicknesses, absolutely.

A good baja car is around 400, but I'd say the average is more towards 500. Anything above 550 is severly overbuilt and has very little chance of a good finish, and anything below 360 is underbuilt in some form, but has a chance of finishing well. Anything under 330 is trash...

We will be under 350 next year, this year was 360 and with a 1st in the endurance and no breaks I'll uut it up against anyone else.

Yeah, that's about standard for the better designs. I've seen lowers as thin as .035 that have finished races.

Was this LeTourneau?

Um well we have run 0.035" for the past four years.

We had 23x8-12 Carlisle AT489s up front and 23x8-12 Dunlop KT403s in back. 12x7 Maxxis 8-spokes for wheels. We had to run the 12s because of clearance problems with the rear brakes on our 10" ITPs. They were the lightest 12" wheel I could find on short notice. I think Keisler makes spun 12" rims, but I could never get a hold of them.

there are 25's lighter then that.

But Letourneau did kick some ass. I kept expecting to see them get towed in every lap, but they just kept going and going.

Yeah, I expected the same from them last year, but they are actually very robust cars. They were the team that cartwheeled down the massive hill (which, honestly, would have totaled our car), and finished in the top 10.

We will be under 350 next year, this year was 360 and with a 1st in the endurance and no breaks I'll uut it up against anyone else.

Um well we have run 0.035" for the past four years.


Like I said, underbuilt in some form, BUT with a chance of a very good finish. You guys do a very good job of losing weight in the right places, and understanding the risk compromise that goes with it. But, I have to add, the car that does well for you guys has 2 years of development, your primary hasn't had a good endurance showing in the last two years, and you are one of the exceptions, not the rule.

Like I said, underbuilt in some form, BUT with a chance of a very good finish. You guys do a very good job of losing weight in the right places, and understanding the risk compromise that goes with it. But, I have to add, the car that does well for you guys has 2 years of development, your primary hasn't had a good endurance showing in the last two years, and you are one of the exceptions, not the rule.

Design optimization is what I prefer to call it. The primary car has had problems cause it usually has some new design that has small long term issues things like the driver not driving smart and rolling or cheap sprocket failing at random times. Root cause has had nothing to do with the weight factor of the car. And the car have been in development since 2001 basically, not the exact design but suspension geometry, handling characteristics, materials,and tube sizes.

Also if you look back at pre-05 BYU used to dominate the west. Their cars were always 325lbs or less and they smoked everyone.

Weasle, what 25s are you talking about? I couldn't find a single tire from a major manufacturer under 13 pounds (the Dunlops are rated at 13) for a 12" rim. Our big problem was stepping up to the larger wheel size, which is where the majority of the weight gain came from. If someone sold an affordable 12 inch spun aluminum wheel, I'd buy it.

might try douglas wheel, the alumalight blue label spun wheels are probably the lightest you can get (.125 wall spun aluminum), plus they have plenty of area to machine off to make them even lighter in the hub area depending on what hubs you are using.

the maxxis Razr iMX Front tire weighs just under 8 lbs .. i know the carlisle 489s are a favorite for dunners that don't want to run paddles because they are thin and light weight for UTVs.. but they also can support a 1200 lb rhino.. so i would imagine you would want to stick with quad tires since they don't need to support so much weight.

the maxxis 4speeds are a little lighter than the 489s. we use them for all of our race Utv's. they work really well.

g-

you'll like this team group shot -
http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83333.jpg

for some reason - everyone liked our shirts...
http://opiebennett.com/MiniBaja/CSUSMiniBaja6108/stp83334.jpg

AWESOME! Sounds like you guys had a blast! I wish I woulda done that in school but..

So, I gather the only way I'm going to really shave weight is to go back to a 10" or smaller wheel and matching tires? Maybe get down into the 10 pounds per cormer range?

Small tires suck, imo. They don't absorb nearly enough of the impact, You want to reduce rotating mass but you also want good energy absorption. Dunlop makes some light 25's as does Maxxis.

The 489's are heavy for the 25's. Douglas rim are about the lightest but I think the Kaisers are lighter. And yep you can machine out the centers some.

i'm in montreal right now. i completely brought my "welder'd it myself" shirt. that thing is awesome.

Weasel, wanna go teach the guys a thing or two about lightweight design http://www.pirate4x4.com/forum/showthread.php?t=691256 :grinpimp:.

Our car was 365 with a full tank and a 10BC fire extinguisher (no 5BC at any stores near us before the damn race :mad3: ).

eh yeah, I thought about it but some times it would be like talking at a brick wall, some things are hard to type out. 365 is pretty dang light, how did the car last?

Well other then breaking the 3/8ths rod ends on our lower control arms in the front during endurance, the car ran well. I actually rose a stink about those rod ends being too small but being the new guy (who ended up doing most of the work anyway) no one listened to me.

Its funny, your car and ours are pretty similar in design and philosophy.

I'll throw some pics up when I'm back down at school and can grab them off our server.

I saw this on the SAE forum, Cornell needs to learn how to weld...
http://img178.imageshack.us/img178/5894/dsc4840yd3.jpg (http://imageshack.us)

where was that at!!?!?! :eek::eek: That is some scary crap. We have rolled previous cars hard enought to shift the cage back but never broke off the front section.

No. They need to learn how to design. If those were unsupported weld joints it was a design failure that resulted in a broken weld.

Holy fucking...damn. I ain't even sure what to say.

From an onlooker

That's not what happened to that car. I was behind him on the first lap when it flipped. He never hit the brakes.

Instead of taking the turn on the outside where its smooth, he cut in across the inside forgetting there was a small jump there. He never flinched or anything, he was full bore the whole time. At those speeds you're not coming off a short jump like that cleanly. Its sending you over. And it did. I saw the belly pan and then the car fell apart in front of me.


From the Driver
Hey,

I am the driver from Cornell. I had mis-judged the size of that kicker, and hadn't realized how it tapered up towards the inside of the turn. I took it too close to the inside, and was kicked over forward. There were at least 4 other cars that I saw in the first 30 minuets of the race do the same thing off of that jump. I guess someone had to do it first.

However, I do feel that they should have done a parade lap like was done in Rochester last year, epically considering how they changed some of the course after the walk. if that's the Stony Brook driver who posted above me, I heard you radioed back for someone to check if I was alright. I appreciate the concern, and walked away without a scratch.

-Alexander
Cornell Baja Racing

The SAE forum thread

http://forums.sae.org/access/dispatch.cgi/bajasae_pf/docProfile/102469/d20080617194226/No/t102469.htm

Happened on the first lap :laughing:

I talked to the cornell driver at the Liquor Store (man there are alot of hot girls in Magog) after the race. He was saying that the judges were really concerned about the rules since their frame technically meets spec, and was properly welded upon visual inspection.

I'd bet on thicker frames and more bracing for next year and an enforcment of the continuous FBM rule.

No. They need to learn how to design. If those were unsupported weld joints it was a design failure that resulted in a broken weld.

The joint should have been supported, I thought you had to tube members down to the frame with in a certain distance of that node.

The joint should have been supported, I thought you had to tube members down to the frame with in a certain distance of that node.

only if you're using front bracing... if your using rear bracing, that is not required.

The joint should have been supported, I thought you had to tube members down to the frame with in a certain distance of that node.I have never gone over the SAE Baja rules...I was in FSAE:flipoff2::grinpimp: If that was legal under the rules then they have both a rules failure and a design failure.

It would be interesting to see the terrain and how the car landed to cause the joint to fail like that. I would normally expect to see a significant amount of bending in both the down tubes and overhead tubes before the weld area ever broke. It looks like somebody just took a Saws-All to the down tubes. The rest of the car looks perfect. Betcha our cars wouldn't fail if we were required to build a real space frame.

only if you're using front bracing... if your using rear bracing, that is not required.

Thats right, forgot about that. I not sure I understand the rule as it seems like driver protection would be of greater importance then the rear engine area.

I have never gone over the SAE Baja rules...I was in FSAE:flipoff2::grinpimp: If that was legal under the rules then they have both a rules failure and a design failure.

Don't go starting anything wing boy :flipoff2:

It would be interesting to see the terrain and how the car landed to cause the joint to fail like that. I would normally expect to see a significant amount of bending in both the down tubes and overhead tubes before the weld area ever broke. It looks like somebody just took a Saws-All to the down tubes. The rest of the car looks perfect.

Yeah I argee which make you question the welds. We have severely bent frame before and they always bent and deform. We havr shifted the cage on old cars two inches to one side and atleast three inches to the rear, rwo different times but never broken any of the welds.

(man there are alot of hot girls in Magog)

x2 must be something in the water. although at 15.50 for a pitcher of beer i'm not moving there anytime soon.

Anyone have pictures of the University of Louisiana at Lafayette red and black car. They placed 4th overall in Tennessee, 10th overall in Canada, and had the same number (I think 45) at each race. I graduated in 06 and the car I built finished 6th overall in Portland, OR. Glad to see you guys are still keeping Baja alive. I wish I could compete every year but I am typing this from a real job.

Well, how are everyone's designs coming for this year? We're hoping to have our prototype (second 2008 entry that got put on hold) running in a month or so.

Wes Thomas
Missouri S&T Baja SAE
Project Manager 2006-2008

I was searching to see if anyone on this site was involved in SAE Baja, and found this thread. I figured there had to be some Pirate guys who were doing this. This will be my first year to do it. I am from the University of Arkansas Little Rock, the team finished 46th in the '08 Illinois race. I was looking at some of the pics that the team took at the Illinois race, and I recognized some of the rigs posted in this thread.

who had the car with 31" tires a few years ago? Anyone have a link?

The 4WD with the solid axles and a couple feet of ground clearance? San Juan State, 2007 midwest (South Dakota) event.

The 4WD with the solid axles and a couple feet of ground clearance? San Juan State, 2007 midwest (South Dakota) event.

Try again...

Sacramento State Mini Baja team...


there are a bunch o pictures in this thread -
http://www.pirate4x4.com/forum/showthread.php?t=568481&highlight=mini+baja

I knew that. Just making sure you we're on your game.

bump.

cornell's car breaking in half was at montreal. they apparently dont know how to weld/and or use their brains. the butt welded the roll hoops together and welded on very low amps. they were lucky to make it through dynamics day.


who has their cars rolling? our car(auburn) started rolling about mid march. 3 weeks to go!

bump.

cornell's car breaking in half was at montreal. they apparently dont know how to weld/and or use their brains. the butt welded the roll hoops together and welded on very low amps. they were lucky to make it through dynamics day.


who has their cars rolling? our car(auburn) started rolling about mid march. 3 weeks to go!

Wrong thread... http://www.pirate4x4.com/forum/showthread.php?t=722253&page=5

Wrong thread... http://www.pirate4x4.com/forum/showthread.php?t=722253&page=5

thanks idk how i missed that

This question is for Jeremy from Auburn (Baja Driven). At the end of your post about CVT's, you stated some times that your car ran and you said that yall timed it with photogates. What kind of timing system did you use? Did yall buy it or build it. If built, how did you build it and what components did you use. Thanks