Man...Quiet lately...Here's a pic of Walker Evans' rig...Talk about balance...It's about as good as it can get IMO...

Yeah, i though it was pretty quiet too.

maybe everyone's left the :vader2: and gone to the :trooper: ?? heh heh!

neat balance on that rig, bet that was a butt-clencher to drive out of!

Jamie

Jamie

dont you just wish that we had access to that kind of terrain to drive in eh!

I aint seen a crack that big since I got drunk at the office party and went home with the cleaning lady......

oops. :flipoff2:

ouch!! :barf: :barf: :barf:

[B]Yeah, i though it was pretty quiet too.

maybe everyone's left the :vader2: and gone to the :trooper: ?? heh heh!

Guess I didn't miss much. My house got struck by lightening on Monday...no computer, TV, internet, ect, unbelieveable how productive I've been the last 3 days!

Johnathan

That is very nice. There would be no way my rig would drive down that and sit there like his. Guaranteed mine would square up on its front axle and then up on its roof.

Wonder what sort of weight drstribution he has got front to back. Looks very light in the rear. Wheel base????

At the moment mine is too short in the WB and very front heavy. I would guess 60/40 to the front maybe even more (based on the compressed lengths - I havent weighted it yet) I find its good to drive up stuff cause the front always idels up and the back always follows. In the old config (rangie tray) with more rear weight had I lot more trouble getting the rear to get up stepups. Would have to use momentum for the rear where the front just idels. Now on all steps ups I just idle the front and idle the rear. But as soon as I point the thing down hill it feels really bad.

Still got more work to do but this will have to wait for the D60/D70 combo. Just going to wheel it as is and be ready to stand on it driving down hill.

:smokin:

Sam

I've been quite lucky with the balance of my project90 (it's a 300Tdi D90 i built up from chassis, with full cage,lockers, 35"'s and other 'stuff').
i put it on a weighbridge, and was about 100kg difference between front and back axle weight. pure luck that it came out as close as that, but makes driving easier and more controlled.

Jamie

So whats the best weight distribution for rock crawling??????

Carnt see that walkers rig can be 50/50 but I dont know the specs at all.

Sam

Originally posted by Strange Rover
So whats the best weight distribution for rock crawling??????

Sam

i've not done any proper rock crawling (not many rocks here in Blighty!) but from 'playing' on ramps, and from previous discussions on the D90 list some time back, i got the impression that a near equal front and back weight was better. vehicles i messed about on a ramp, without good distribution, seemed to have more axle twist when reversing up the ramp, presumably because the weight of the engine/tranny was helping to 'push' down the end of the vehicle and compress the springs a little more.
same for driving up things too i guess.

Jamie

Sam,

I would expect that Walkers has 60-75% of the weight on the front. The rig has been here in Las Cruces several times including in one of the competitions this year. It is built more like an off-road racer with very long 4-link arms (from the back axle almost up to the cab!) with no anti-squat that I have detected. This is not surprising given Walker's off-road racing background. I have no idea what the wheel base is, but I suspect it is in the 108-115" range. The Farmington NM boys seem to like wheelbases in the 102-110" range on their buggies. Note that Walker is running 37" MTR's even though the rules allow somewhat larger tires. These do seem to be effective in this environment.

Rich

Originally posted by rhills
Note that Walker is running 37" MTR's even though the rules allow somewhat larger tires. These do seem to be effective in this environment.

Rich

Effective yes...But also keep in mind that Walker has a HUGE GoodYear sticker on the side of his rig that he runs with ALL the time. Sponsorship does have it's advantages.

I wonder what sized tire he (and most other top 10 ARCA (RCAA?) competitors) would run if the GY MTR came in a 40"...

--D

Given that walkers rig is very front heavy and I suspect that most of the competition rigs are front heavy. How does Walkers rig stay so crossed up when its pointing down hill like in dougs pic. That photo just amazies me. The only way I can see the rig sitting there like that is if it have very soft spring rates. And in the rear incredibly soft rates to stay cross up pointing down hill.

Got any pictures of the thing articulating on flat groung or pointing up hill. Ive got an small picture walkesr rig crossed going slightly up hill (very similar to a ramp) and it has most of the travel in the rear and not much in front. This was an old picture but is this how his rig is set up - front heavy and stiffer rates in the front?????

I would love to have that kind of stability driving down hill and I would love to understand how to get it without going to a 50/50 weight distribution cause I really like being front heavy. There must be trade offs somewhere - Walkers rig carnt have it all???

Sam

What are peoples thoughts on weight distrubution and spring rates?????

My feelings are to keep the front and rear rates about the same even if the weight distribution is not.

Sam

Sam,

If MTR came in 40", Walker would run them. I don't doubt this for a minute.

Many of the hard core rock crawlers run their engines back. They like to have the crank pulley behind the front axle.

Walker's rig does lift a rear wheel when dropping a front wheel off a ledge, as you would expect from his weight distribution. Close inspection of the picture shows that the rear left tire could be in the air. Given that he appears balanced front to back, he has to be running very soft springs in the back. I think one can get away with this if one runs very long 4-link arms and has the engine behind the front axle.

I was out there that day that crack was pretty big. A couple of trucks rolled right about where he is in that picture. most took a line a little more to the left, some of which ended up on the left side. There was a guy with a airbag setup that did not even lift a wheel going through there. I do not think he was as balanced, more travel in the back but it worked really well