Suspension Combo - input wanted.

[Buick Motorsports]

Well I have finally settled on the upgrades and additions for my, Pro-Touring project, Buick suspension. I think I have found a setup that will drastically improve handling while still maintaining decent street manors. I would like any input from the forum collectively on this combination.



Tubular rear control arms from UMI – polyeurathane bushings.

Polyeurathane bushing kit for front suspension and steering.

Addco sway bars – 1 3/8” rear and 1” front.

Bilstein shocks.

Factory rubber body bushings. This is one of those ride/streetability compromises.

Suspension techniques 1” drop coil springs.
Rear seat braces(helps tighten body for T-top cars)
Front frame braces and connecting brace.(ties front frame together)



Simmons racing wheels with 245/40/17 fronts and 285/40/17 rear.



Next year will see the addition of Baer Brakes.



Any and all constructive input will be greatly appreciated.

Jason

[Pro-touring towncar]

Jason, seems like a good plan. They make alot of suspension stuff for the G-body.

Tim

[796spdbu]

Buick Motorsports, what size wheels are you running.I figure that they are 17" diameter but what width and back spacing.On my 79'bu project I was wanting to run the 285-40-18'son the rear on an 18x9.5"-18x10" with a 4" back space with a narrowed 9" rear axle.Not trying to steal the thread but your tire sizes interrested me.Thanks for any help you can give me.

[dennis68]

Any special reason you want to run the absolute worst arm possible on the rear? You would actually handle better on worn out stock arms. Poly is the worst thing thing....no wait. Delrin/Teflon is worst, poly is second to the worst thing you can but in C4L set-ups.

[TPI Monte SS]

I've been playing with G-bodies for about 7 years. I'm no expert, but I've put enough street miles on them to have learned a few things.





Tubular rear control arms from UMI – polyeurathane bushings.

The lowers will be fine. I recommend Edelbrock adjustable uppers though, with the spherical bushing on the frame side. I have this setup on my '88 and like it a lot.


Polyeurathane bushing kit for front suspension and steering.
Too stiff and squeaky! Stay with stock rubber, IMO.


Addco sway bars – 1 3/8” rear and 1” front.
They might be OK, but a cheaper and better choice are the stock F-41 bars.



Bilstein shocks.

Factory rubber body bushings. This is one of those ride/streetability compromises.

No complaints on either of those. I have them and really like them a lot!


Suspension techniques 1” drop coil springs.

What's the rate on them? I have Eibachs in my '88 and am happy with them.


Rear seat braces(helps tighten body for T-top cars)
Front frame braces and connecting brace.(ties front frame together)

Both are good additions, and you can also add bracing from the core support to the inner fenders.




Simmons racing wheels with 245/40/17 fronts and 285/40/17 rear.


Sounds good. I have 245/45 17s on my '88 on all 4 corners. The ability to rotate tires is a plus.

Good luck with your project!

[Norm Peterson]

Tubular rear control arms from UMI – polyeurathane bushings.Not the best choice from a 'bind' / 'addition of unintended wheel rate' point of view, but do-able. FWIW, the poly can be modded to eliminate some of the bind.

I've also found that poly up front tends to squeak more noticeably than at the rear.


Addco sway bars – 1 3/8” rear and 1” front.Either you have lots of dragstrip use in mind or you have those backward. The F41 bars for my '79 Malibu (which I bought new to order, not off the lot) are 32 mm (1 1/4") front and 22 mm (7/8") rear.

Any idea what the rate for those ST front springs is? Actually, you can get Moogs in a variety of rates cheaper than just about anybody elses, though you may have to trim them for a particular ride height.

Norm

[gmachinz]

I vote for Hotchkis upper arms. As for rear tire size, anything more than 5.25" backspacing and you're getting into the framerail. I run 285/40/17's (5.25 b/s) out back on my Monte and it rubbed a hair until I installed the Hotchkis rear susp. package which stiffened everything up! Keep with one manufacturer-I chose Hotchkis. I have a ton of experience with 78-88 G-bodies-I've torn down more than most people have built so I know what they need. Email me if you have Q's. [email protected]

[Buick Motorsports]

Thanks all for your input. What is the general consensus on polygraphite bushings in lieu of the OEM rubber?

796spdbu...I don't have all the specs at my office for the rim combo. I will IM you the information when I get home.

f-41 sway bars... cheaper if bought direct from a dealer?

[dennis68]

Poly is OK in the front but NEVER in the rear.

[Buick Motorsports]

Poly is OK in the front but NEVER in the rear.


So you suggest nothing other than the stock rubber for the rear, dennis68?

I need this input from everyone, it's greatly appreciated.... I want to finalize my combo, so that i can start ordering.

[TPI Monte SS]

Jason, the F41 bars would be cheapest if you can find someone selling them either on the Evil site or from someone local parting out a Monte Carlo SS, Olds 442, etc. The F41 suspension was also available on base-model cars as well; look for F41 on the SPID decal in the trunk.

[WOOSHH]

I would go with the GW delium bushing lca in the rear.This is absolutely the best for handling........

[Norm Peterson]

I would go with the GW delium bushing lca in the rear.This is absolutely the best for handling........Umm, no.

Don't confuse flatter cornering, a slightly stiffer ride, and more side-to-side head toss with better handling. Do a search on the term 'bind'; it's the dark side of using poly, delrin, or Del-A-Lum in rear control arms.

Be careful about describing anything that has to do with suspension performance as being the 'absolute best'. Very few of these things are, and taken individually I can't offhand think of any.

BTW, welcome to the site, and understand that the above is intended as education rather than flame.

Norm

[David Pozzi]

I'd rather have solid frame to body mounts, don't tie the front body to frame solid unless the frame mounts are solid. I'd go with solid now, and if you have ride problems try polly or rubber if you have to. I just don't like the frame moving separately from the body.

Use stock rubber bushings on the A arms if you want a better ride. Delrin A arm bushings don't make the ride a lot rougher but rubber A arm bushings are not so bad.

[dennis68]

So you suggest nothing other than the stock rubber for the rear, dennis68?

I need this input from everyone, it's greatly appreciated.... I want to finalize my combo, so that I can start ordering.

In the case studies that have been run as well as some real world results; running rod ends in the lower positions is an improvement over stock, but leave the upper alone.


I would go with the GW delium bushing lca in the rear. This is absolutely the best for handling........
Actually it's the absolute worst thing to put in the arms in this particular application (C4L that is). The GW bushings are actually referred to as Del-a-lum, just a correction. Do some searches in this forum for "bind", "poly", and maybe "C4L" or "converging 4 link" for some more reference material.

This site is probably one of the most advanced technical sites as it applies to cars and handling (cc might have us beat but it does require a fairly advanced level of education to follow at times). Stick around and learn a thing or two.

[ProTouring442]

In the case studies that have been run as well as some real world results; running rod ends in the lower positions is an improvement over stock, but leave the upper alone.


Actually it's the absolute worst thing to put in the arms in this particular application (C4L that is). The GW bushings are actually referred to as Del-a-lum, just a correction. Do some searches in this forum for "bind", "poly", and maybe "C4L" or "converging 4 link" for some more reference material.

This site is probably one of the most advanced technical sites as it applies to cars and handling (cc might have us beat but it does require a fairly advanced level of education to follow at times). Stick around and learn a thing or two.

Here's what I was going to run on my 72 442. GW lowers (I think... the ones I want have spherical bearings on one end) and the Eldebrock uppers which also have spherical bearings on the frame end. If you don't run the arms with the spherical bearings, as the rear twists you get bind. Even the stock rubber causes a bind, but because of the more flexible nature of the rubber bushings, you get less bind then with a urethane or the GW Del-a-lum. If you have a solid bushing on both ends of the arms, the bind is awful and causes a very stiff ride with suspension that just wont work!

Keep in mind that I am no expert, but with all I have read I think this is a very good way to go, having the spherical bearings on both the upper and lower arms.

Shiny Side Up!
Bill K
'72 442 "Inamorata"

[Robbie-87plz]

What was the final decisions in regards to the front end? I'm interested in this setup...TIA

[yody]

i am pretty sure you can run bigger than a 245 on the front of that car, i think a 9.5 will work on the front with a 275, although i don't own one. also listen to dennis the menace and hey norm on the rear suspesion thing

[MrQuick]

im about to crap poly. C4L = https://static1.pt-content.com/images/pt/2005/04/beatdeadhorse5-1.gif

[dennis68]

Over and over again.

[indyjps]

doesnt this car use the same "metric" chassis as circle track and late model guys are running. has anyone with a g body looked into using some of this equipment.

[Norm Peterson]

Most tubular front UCA's (particularly the adjustable ones) and any tall ball joints have their origins in roundy-round racing. And some of the specific springs, since if you're looking for something like 1000 lb/in or heavier fronts that's where you can find those. Some shock brands are primarily associated with circle track. But not much that I'm aware of for rear suspension linkage pieces. A lot of the more specialized circle track rear suspension components and/or their arrangement details are not equally happy making right turns as lefts or simply aren't particularly well-suited to street use (e.g. birdcages).

That said, I do know of at least one individual (Jon A, over at Corner-Carvers.com) who has fabbed his own aluminum-tube/rod ended LCA's for a 4th gen F-body from individually available stock car racing components, and has a "how-to" posted on his website. That would work for an 80's vintage G-body unless you intend to keep the OE-style rear sta-bar (which bolts to the LCA's and loads them up in bending). I think he's recently tinkered with it a little and made it a bit more street-friendly (all rod ends in a stick axle rear suspension can be rather harsh).

From a PT standpoint, the latest iteration of those aluminum LCA's with an end-link style rear sta-bar and a 3-link/PHB conversion would be preferable, and I think Marcus (www.SCandC.com) has the 3rd link/PHB part of that under development specifically for that chassis.

Norm