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Discussion Starter #1 (Edited)
I started a thread awhile ago about how I was gonna race my rock lizard chassis, then plans changed about 5000 times, so figured I'd start a new thread now that I'm actually working on it (can read all those ideas and the very beginning of the lizard here: https://www.pirate4x4.com/forum/general-4x4-discussion/2671184-4800-rock-lizard-build.html). I don't know if I'll ever race this buggy, I think some small races will be fun but we'll see.

TL;DR -- LQ4, Atlas, 04 super duty axles, trailing arms, bypasses, 40s, etc. Modified Rock Lizard 1.75 chassis

To get up to speed, I bought a Rock Lizard chassis from Fabn801 out of Utah in like October. He special made a 1.75" tube chassis for me in the event I would race it.



Fast forward to April, and after changing my mind a bunch it was in this shape:





I changed the chassis quite a bit. I widened the whole thing about 10", I completely redid the nose since the stock one was more boxy than I liked, I raised the roof line since my seats wouldn't fit, etc. and it was sitting with a Toyota 3.4 drivetrain. At this point everything had been pretty cheap boy driven.

And then at the end of April I said fuck it, I don't want another POS rig where I cut every corner. So I'd throw some money at some of what I had and step up the build in other parts. So my pseudo plan was to build a good drivetrain that will last a long time and I can swap into future builds, and then still rock the lizard chassis and just have fun with it and have some good parts at the end of the day I can carry on to the future. Like I said in the beginning, not sure where I plan to go with this, I just want something fun that can do a little of everything and I can get some experience building as my first buggy.
 

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Discussion Starter #2
So first task of my new plan was to buy an atlas, so first week of May I got paid and placed an order for a 2 speed with every possible upgrade they had. Race case, 3:1, 300m, superpolished gears, heim shifters, yada yada. If I was gonna buy an atlas I wanted the tits. Fast forward to about 3 weeks ago and I finally had all the parts to actually get building.



I also wanted trailing arms, because I wanted trailing arms. I also wanted dual shocks, because I wanted dual shocks. Used a few shocks from my last 4500 build, and bought some new ones. Also bought a Kibbetech hand brake because I thought it looked cool and with front dig I now had an excuse to buy it. Trailing arms are the 48" Ruffstuff WIY kit, 1.25" heims on both ends. Axles is a 04 super duty 60 front and Sterling 10.5 rear. Artec trusses for both and Artec hydro ram mount/guard too (last one still laying around).



I picked up a LQ4 6.0 and 4l80e from a buddy, got those cleaned up and tore the engine down a little at this point to make sure everything looked fine and it did. Still debating how I want to build it up, I will admit twin turbos are high on the list but might just do some basic stuff for now and call it good and upgrade it more heavily later on.



Cleaned everything up and bolted it together for mockup.





Fits pretty well, which I already knew more or less since this was one of 3 engines I had already test fit months ago.

I went to order bushings and mounts from Ruffstuff to mount the trans (already had LSX innovations motor mounts ordered), and Ruffstuff wanted $6/bracket. Long story short, this was enough to push me over the edge and buy a mini cnc plasma table last week which I got in on Thursday. The LSX innovations motor mount stand off arm was way too short, so first up was to cut out new mounting arms to hang the engine.



With the motor mounted and tacked to the chassis I lifted everything back up to ride height with the LS/4l80/atlas now hung (or in the case of the trans, sitting on a plywood spacer off a cross member). Ruffstuff bushings should be showing up today to mount the tranny. I also ordered an atlas tail housing mount from TMR that will get here someday.



That then brings us to yesterday. With the drivetrain where I wanted it, and the chassis at ride height I could get accurate measurements to update my 4 link (my original layout was setup for the toyota drivetrain and honestly was shit). Did more research, played with the triage calculator more as well as made a 2D layout in solidworks to calculate pinion angle and driveshaft plunge through the travel, which took a bit of work but I got to less than 2" of plunge through 24" of travel and -2.5 roll axis and ~75% AS which I'm happy with.

With that done I drew up the rear link tower in CAD and cut it out and tacked it up on my 10.5



I also went and bought a press to finally use the dimple dies from TMR I've been sitting on for nearly a year.





I also cut out the lower link "platform" that will attach to the chassis and started welding that last night, hopefully get that welded and tacked on today and maybe get the other rear link mounts on. And that brings everything up to date...
 

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Discussion Starter #4
is 1.75" main cage tube for racing still up to the rules? I was thinking as guys keep going faster and faster 2.0 would become the norm.
Correct, at least for Ultra4 main cage sizing is weight specific, in this case I would technically be legal up to 4400lbs. Though that is one of my hesitations to possibly do a big race, is the chassis just feels small and flimsy compared to the two previous Ultra4 cages I did that were 2.0. Obviously this still has a lot of bracing and a long way to go though, and racing (if at all) is a potential side effect and not the outright goal for this.
 

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Discussion Starter #10
Thanks for sharing and keeping some stuff on the ol PBB.
Took a bit of thought to decide to keep a log of everything on PBB, but someone on instagram told me they came across some of my posts of putting a v8 in a lizard from the past so figured at least some people might find some use from this :D

Cool build so far! What kind of plasma cutter table did you get? Specs?
Thanks! It's a Langmuir 2x2 table. It's $1500 and then clamps onto a normal hand plasma torch. Software is another $175. I have a little hobbyist cnc mill so already had the software and already had a plasma, and had been looking at this table for awhile and said what the hell may as well pull the trigger now. It's not big, but it's big enough for 99% of the stuff I do, and is already proving more than it's worth imo. I just got their water table add on in the mail today and installed though haven't tried it yet.



accessory drive is going to be tight ! axle in front of crank pully?
Very true, and to be honest I hadn't even thought about accessories until you mentioned that :rolleyes: I've had concerns the nose I made was gonna be too tight since going to the LS, worst case I'll just cut it off and redo the front. And yea, I'm shooting for 114" WB which should put the front axle right around/in front of the nose tube. If I ever did something like Ultra4 needless to say I'd have to make bumper extension because of that.
 

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Discussion Starter #12 (Edited)
Made two steps forward and one step backward today.

Made some upper mounts, like everything else these will be further braced but I wasn't sure how I wanted to it right now so just cut the two plates.



Made the axle side trailing arm brackets and welded them up and tacked them onto the housing.



Cut the uppers I had laying around down to 52" and tacked them up and bolted the axle in.



I think it looks sick, but you might see a glaring issue.





I got caught up in the fancy new plasma table and all my cad models and forget to run some basic logic through it. Pretty obvious that running your uppers across your trailing arms that your shocks bolt to might have clearance issues... I figured I'd figure the shocks out when I got to them. Would've taken 10 seconds to realize there'd be issues and check it in the models or just lay everything out.

Oh well. Before I left the shop I punched a few numbers really fast, there's a few ways forward without scraping the whole setup. The most likely right now is moving the uppers outward on the axle and running it single lower triangulated. I only have to move the upper mounts and everything else can stay the same, the only "negative" side effect is my roll axis will increase to ~0deg from -3 that it was originally supposed to be. Not a big deal at all. My lowers are already triangulated at 45deg, which from my quick research should be totally fine (I assume everything I read was the angle between the arms, and not the angle of the arm relative to straight ahead...). This is also beneficial since the tail of the chassis is so narrow, I really need to keep all the shocks centralized otherwise I need to redo the end of the chassis. Also, moving my trailing arms to the top side doesn't really solve anything since I'd still need to push the axle mounts outwards so the shocks have good leverage on the axle and as mentioned can't run the trailing arms parallel since the chassis is too narrow.

TL;DR-- there's options, easiest is to turn my axle tower into a cool paper weight and build two more towers and shift the uppers to roughly above the lowers on the axle. Sucks, but could be a lot worse considering the oversight I made.

EDIT: talking to some guys and thinking about it, a Y link upper would fix everything and not compromise anywhere I think... We'll see tomorrow
 

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Discussion Starter #14
reason for raising the lower links in the bracket above belly tube.
Gets driveshaft plunge <2" over the full 24" of wheel travel there. Not exactly ideal, and I'm gonna run some tubes down to brace it since that tube will probably twist on its own, but that's the best geometry I came up with between roll axis/anti squat/driveshaft plunge.
 

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Thanks for sharing. You sure seem to like to redo a lot of things though. Seems very time consuming and counter productive.
 

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would it be better to move lowers as wide they can be to gain more lower shock mount width. looks kind of narrow now, then make uppers to clear
 

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Not that I would do it but there's plenty of rock bouncer rigs run the trailing/leading arm as uppers instead of lowers. Then again a Y link upper or some beefy bent upper arms would gain you clearance as well.
 

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I'd be doing a lot more thinking on what you want and how you go about building that rear link setup. Suspension is the single most important part of a build. You seem to still be building around the chassis. That's the wrong way to go about it. The chassis is cheapest and easiest part of the build.
 
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