Is anyone using aftermarket upper and lower control arms (coilovers included)?

I know I am not building a race car but it would be nice to have a car that handles.

Also, has anyone used the 4-link rearend set up? Is it worth using a link set up or are leaf springs just as good?

At this point my car has been completely torn down except for the rearend and engine. I have bombarded Vikki with all my 'stupid' car questions and I thought I would get everyones opinion as well.

The next stage with my car is media blasting and I guess I should be asking questions about this area instead of control arms.

Thanks for everyones help and please keep it rolling this way.

Ron
([email protected]

I'm just finishing up a 6 year project and I'd recommend staying away from things like changing your control arms unless you really, really need it for your application (and it sounds like you don't).

Each mod like that requires a lot of money and typically, you change one thing, and related components need to change as well. It's like a chain reaction.

There are many ways to get better handling -- bigger sway bar, different springs, new suspension parts, etc.

Good luck on the project!

John

Aftermarket upper control arms allow you to set more caster. That will improve high speed stability, especially with radial tires. There's little advantage to swapping lower arms unless you're going to a coil-over setup that requires it. If you do change the upper arms, don't discard your original parts. One day you will want them to keep the car correct. They can be easily swapped back if you change your mind.

There are also tie rod ends available that reduce the bump steer by bringing the steering linkage parallel to the a-arms. They aren't parallel as designed and the wheel changes toe dramatically during bump.

http://www.scandc.com/balljoints.htm (scroll to the bottom)

I think dialing in more caster and fixing the bump-steer are worthwhile changes.

Go to premium shocks too if you have the budget.

David Pozzi has good information at http://www.pozziracing.com/

As John says, this stuff can burn through your budget pretty quickly, so defining goals is important.

Here is my setup. I did mine years ago. I'll have to check is see if the bump steer needs fixing, now that I know the SC&C tie-rods exist. The arms don't do much for camber gain, but they do allow you to drop the UCA mounting location without hacking the mounts. Another key element is the delrin bushings. They are great for improving handling without increase ride harshness.

SC&Cs taller ball joints are a new alternative, and even better is the taller spindles that are now available to improve the camber gain.

Taking the flex out of the subframe and body by solid body mounts and subframe connectors improves handling without reduce the ride quality. The one thing I did when re-doing my suspension was staying away from stiffer springs, so I would not sacrifice ride quality.

In summary:
Fix the camber gain
Increase the caster
Remove bump steel
Get low friction bushings for the control arms
Remove chassis flex

/forums/ubbthreads.php?ubb=showflat&Main=4607&Number=29677#Post29677

If I had seen the fully adjustable upper arms from SC&T first, I wouldn't have bought the GW arms. They gave me more caster, but I was disappointed how many shims it took to get 3/4* of camber and that was about the limit of the shim stack on my subframe.

I measured the front end geometry on the bare subframe. That was an easy task with the subframe sitting on stands with no springs installed. Basically I proved that what David Pozzi says is correct. The tie rod ends need to be dropped somewhere between 0.4" and 0.5" lower than stock to make it neutral bump. I can't find my graph of the bump steer, but it was pretty bad. It would explain why my first Firebird pulled side to side while shifting. I've only seen two solutions. One is the Howe tie rod ends carried by SC&T and the other was the Baer adjustable end. The Baer solution is a Heim joint and I don't trust it... I'm not sure they still offer it.

I didn't mention, but I also went to the Delrin bushings. When you subtract out the cost of OEM upper bushings, installation, labor etc, the GW arms with delrin bushings, upper ball joints installed and already assembled seemed like a reasonable buy. I put the Delrin bushings in the LCA also. The LCA would be a bigger job to swap bushings later on, so this seemed like the time to install them. Another budget buster... The upper bushings were shot when I bought the car. The cross shaft was riding steel on steel even though the car passed Virginia safety inspection in 2000.

The front torsion bar is somewhat hard to reach later with the car assembled, so I went to the Hotchkiss tube bar while refurbishing the front end. That kit included polyurethane bushings. I swapped to ENS polyurethane sway bar bushings on another car, and I like & recommend them.

I also relocated the upper control arm mountings in the subframe by the vertical amount on the Guldstrand template but without setting the mount further rearwards (which gains caster), because the additional caster is built into the GW arms.

Mike, I think you summarized it pretty well.




Project goals need to be set against the budget. The "want to have" list can swell the budget and it's probably more important to finish the project or at least set goals before expanding the scope.

I also put in a new steering gear box that gives me two turns lock to lock. I hope that wasn't a bad choice... Any way you look at it, an old bird is going to need a fresh steering gear.

Oops, third one down should be "bump steer," but hopefully everyone understood.