I am looking at changing my front drum brakes to disks and would like to up grade the front suspension while I've got everything apart. Anyone have any suggestions on what route to go. I was thinking new bushings, springs, shocks and ball joints. Are the new tubular control arm worth it?

I just recently did all of the above except tube control arms. Polyurethane bushings, new springs, all new rod ends/ball joints, pitnum/idler arms, re-man steering box, rag joint. Front disks from a '74 Nova totally bolt on ! I don't see the need for tubular a-arms unless you have to get the car as light as possible. It's going to drive better than new. Happy motoring and good luck !

Also going to a larger sway bar and gas shocks. Don't have them yet.

I went for the Global West tubular upper control arms. Now at $230 for a bare set - it's tough to go wrong, especially considering they are already power coated.

It's not the weight that's the factor. It's the fact that the stock suspension was never designed for radial tires. Your alignment shop will have a very tough time getting enough caster dialed in for a radial tire setup with the stock control arms - you just cannot get enough shims in. The tubular arms also cut the factory bump steer in half.

Here's my favorite 1st Gen suspension site. Enjoy:

David Pozzi\'s Webpage

The Pozzi website is a must read for all firebird owners interested in handling!! The benefit of the tubular control arms is that they change the angle of the tire under load to remove the massive understeer that GM built into the cars.

i have read alot of great stuff on that site. i am contemplating doing his variation of the guldstrand mod. to increase caster.

Scott -

Are you thinking of pulling the lower ball joint back on the lower arm? I have sketched some suspension geometry with this layout, but it's not very developed yet. I know that Global west makes lower arms as well as upper. Do you know if thier's puts the ball joint in the stock location on the lower?

Q

Q,

the guldstrand mod only changes the upper arm, moving it back about 1/2" to increase caster, and lowering it about 1/2" to improve geometry somehow. this guldstrand fellow apparently has been doing racing mods for longer than i've been alive, and you can order a template from him, or you can copy one off david's site. the holes for the control arm shaft bolts are moved back, and each is moved down a different amount to change the angle too.


i dont see how moving the lower arm forward would help, but i'm not an engineer. i dont know what the global west or other kits do to any aspects of the suspension. they look really cool, but not within my budget, so i never really did any investigating.

Guldstrand mod makes a lot of sense, when tire is in up position, the top of the tire is closer to the engine, making the tire flatter at load and lowers the role center. I am collecting suspension parts and plan to try it. I had read that it lowers the understeer by 40%.

CAUTION: If you're doing the Guldstrand mod, here's what no one tells you:

I'm not a suspension expert, but what I'm saying can be verified in the "Chassis Engineering" by Herb Adams (I think you may have heard of him).

If you look at the Guldstrand template, the new holes are in the same plane, whereas previously the front holes were lined up so that the upper control arm pivots angled upward towards the front.

Why did the OEM engineers do this? It promotes anti-dive when braking. This is because of the "soft" factory springs used for a comfortable ride. The side-effect is an increase in caster as the suspension is compressed.

Bottom line, if you're doing the Guldstr template mod, it removes your anti-dive, so better have some stiff springs!

There is another template that recommends cutting off the mount, modifying it and rewelding in a different location (se Pozzi's site). He calls it another version of the Guldstrand, but I think it came from somewhere else. May be a better choice because it doesn't drop the front pivot relative to the rear quite as much. I can't endorse either since I've never ridden in a car that has this mod.

I suggest to anyone thinking of suspension changes, they read several books (I liked the Adams - but there's others) and really understand cause and effects before cutting up your car. The more I've read the more skeptical about "fixing" the suspension geometry.

Pozzi actually recommends leaving it alone unless you're into competition cornering. Frankly, I'd start with new alignment settings more radial-friendly first (see Adams book and Pozzi's site for suggestions). At least it's easy to put back to stock!