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Help, really concerned about fabrication and axle angles

RaceTec Pistons

Active Member
I have a buggy that I had someone building for me and I have found a bunch of issues that I have questions about, could you give me some info?
Major concern... Every IRS buggy I have ever seen had the flanges on the transmission forward of the CV flanges on the trailing arms. Mine are backwards, I think that he mounted the transmission too far back? Everything on this build just seems wrong or messed up. In my head the trans flanges should be slightly forward so that when the axles are level it is just a slight swept back angle and as they go from compression to full droop the compound angle should be minimized?

This is a "professional" builder that was doing this for me so I don't want to seem like I know everything by any means... I am tearing the entire buggy back apart at this point it is a nightmare!!!

Thoughts?
 

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michael.gonzalez

Well-Known Member
A bit of forward-backward placement is acceptable. Not the end of the world for CV angles although it will technically affect it, if slightly. Maybe he couldn't mount it forward for other reasons? Forward is better for Center of Gravity of course.
 

isdtbower

Well-Known Member
It may depend on which trailing arm system you are talking about, and where your ride height is, but generally moving the transaxle center forward slightly tends to minimize axle plunge as the trailing arm arcs forward - up and down. They may have a different way of dealing with plunge or expect the increase in wheelbase or position to be more beneficial. (GG (moving the engline-trans forward), shock motion ratio, etc.) Similar to above.
 

RaceTec Pistons

Active Member
Ok more pictures... I did a couple basic drawings and it seems having the trans cv flanges forward of the out cv flanges would provide the least compound angle over the sweep and the least plunge. The way it is designed it is constantly at a compound angle and has the axles pulling out all of the time... He did already cut the torsion housing for the transmission, but not enough and not clean at all. Seems I have to rewire and reroute everything...

As for the pictures everything is wrong, I have no clue why he put the battery there? I have no clue why he put a tube connector on a solid welded tube. The engine cage can't be removed / opened to work on the engine. The wiring is running through the same holes as moving hardware with no protection. Bolts missing, wrong, not installed all of the way... The picture of the caliper is where he ground down the mounting bracket and now the caliper isn't centered on the rotor. The list goes on! I could have done all of this stuff I just don't have time, so on the recommendation of a friend he took it to a professional fabricator for me... This guy has a shop and a business doing this! Yes, I do have it on a couple pallets, it is jacked up and I wanted some extra security, my jack stands are too short.
Tubing Connector.jpg20200322_123726_resized.jpgTubing Connector on Fixed Pipe.jpg
 

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partybarge_pilot

Well-Known Member
Is that the 4 speed or 5?

Without major redesign of the chassis, it might not go any farther forward. Longer trailing arms would be the easier route. If the chassis is strong enough to take it ......
 

RaceTec Pistons

Active Member
5 speed. That is what I was concerned about, there is so much wrong that really at least 50% of the chassis design needs to be addressed. What would you guys do? At this point do I just have the torsion housing hacked out and start over? The entire engine cage is a mess anyways, do I just start over there and move it all forward?
 

powerbox_builder

Well-Known Member
Just straighten out the silly stuff and run it. I've seen axle/trans placement a lot worse, and they still run around the desert for years. Looks like your biggest limiting factor is the hubs/stubs. Those are some short axles.
 

partybarge_pilot

Well-Known Member
Stuffing a LS and a 5 speed into a glass car chassis was probably an unrealistic proposition. With most projects like this, you are usually better off starting from scratch rather than trying to make something into what it's not.
 

RaceTec Pistons

Active Member
The axles are 25" long? The width was limited by my trailer width and the front suspension width. Partybarge, this was a complete custom build, it showed up at his shop with only the pan! It was started from scratch! I wanted it to be street legal, and it should have all been done right from the start, it was designed to be a 5 speed LS car! What should have been done different? Or I guess I should ask what did he do wrong?
 
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RaceTec Pistons

Active Member
This wasn't meant to be a crazy offroad beast, just a decent car that I could play in the dirt with... It was always going to be a LS 5 speed car. It was a blank sheet deal, I made the mistake of trusting the fabricator I guess... Any positive input or suggestion would be appreciated... I am in Huntington Beach and if anyone knows anyone local that I could drag it to I would appreciate the referral. I want to get it fixed and driveable, I can clean up wiring and minor stuff. I just don't have the time or space to fix the fabrication.
 

RaceTec Pistons

Active Member
The pan has already been cut along with the torsion housing, see below... It is a full cage front to back, seems it is all wrong though from what I am being told...
Body to Chassis Wiring Nightmare.jpg
 
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