A-Body Rear Suspension advice

[BBSkylark]

First I'll give a little breakdown on my car and the plans for it. I am building a 1970 Buick GS Stage 1 Pro Touring car. It will be buick powered with around 550hp (crank). I am going to be running a T-56, C6 Z06 Brakes, 18x12 (335 tire) rear and 18x8.5 (265 tire if I can get it to fit) front rims. Frame is going to be stock with my own bracing welded in for the control arm area's. Car is not being built as a race car but a fun project that will handle well, throw you back in the seat when you push the go pedal and have the stance of a race car (think GT1 Lemans race car stance). I love stance so this will also be important for my build but overall performance will take priority!

For front suspension I will be running Global west style A arms with a QA1 coil over kit (I think). I have not figured out what spindle (AFX?) I will be using. Or Sway bar.

For the rear this is where I am really starting to get lost. I have been looking at all sorts of suspension setup's from stock to a rear set-up with a watts link. Accessible to myself I have a decent mig welder although my skills are not the best I am learning.

I have been reading up on speed-tech bolt on coilover kits for the A body, do you think that it would be a good idea to purchase something like this or fab my own or use a factory coil sping and shock set-up. The biggest thing is I dont want to get over my head and loose interest in the project, it happend to me once when I was going through school and I finally have some funds to divert towards it and get the ball rolling!

Keep in mind I am not building a race car just a real fun street car that I will do some lapping, auto x and drag racing with!



If you have any suggestions for front or rear suspension that are realistically budget concious (I dont need to buy a plug and play kit) that would be great! I am just working on my frame reinforcements right now and once that is done off to powdercoating and I will start on the suspension!

Thanks,

[mild2wildpaintngraphics]

Speed Tech or ridetech are both excellent options. Give Frank at Prodigy a call. He'll set you up.

[UMI Tech]

Hey BBSkylark. If you're considering stock type rebuilds, check our '72 LeMans. It works great and is a pleasure to drive. We've had it drag racing, street driving and on the skidpad and local test track to check slalom times, transition, etc.

http://www.umiperformance.com/catalo..._page=72lemans

If you're looking to do some fab work, we offer QA1 coilover kits.

http://www.umiperformance.com/catalo...ex&cPath=2_143

I'd be interested in working with you on this project for sure.

ramey

[UMI Tech]

Oh, and we can also take care of your front coil-overs a la QA1 in conjunction with our awesome tubular a-arms.

We are including 1/2" taller ball joints in our uppers to improve the camber curve.

Also on deck is a diff mount rear bar with rod ends to the chassis. It'll be three way adjustable. Long arm for handling, short arm for drag.

Ramey

[clu269]

Here is a link to what I am running on my buick. I have not posted any update for quite some time but intend to start new thread to update my progress soon.
https://www.pro-touring.com/showthre...1970-Buick-GSX

[shep]

if you are staying with a conventional spring and shock set up. Double adjustable uppers like edelbrock or currie offer along with some double adjustable lowers will give you a nice set up and remove most of the bind in the rear. After that springs to get you to the drop you want with a rate that complements the front and some double adjustable shocks. This will get you a good start on sorting the rear add a sway bar if needed after you drive it.

[UMI Tech]

Here is a link to what I am running on my buick. I have not posted any update for quite some time but intend to start new thread to update my progress soon.
https://www.pro-touring.com/showthre...1970-Buick-GSX

Checked out your Buick build. Awesome car, awesome wheels and that rendering? I can only dream of being that talented.

ramey

[BBSkylark]

Thanks a bunch everyone and nice build clu! Post some updates I would love to see them!!!

Originally I was going to go with a set of Edlebrock adjustible uppers and Lakewood boxed lower traction bars that relocate them but I dont think that is really what I am looking for.

Ramey thanks a bunch for the information. I am interested in both your front and rear coilover kits and a set of rear adjustible upper control arms with a rotojoint! As for my front suspension I have already purchased a set of control arms but do not have tall ball joints. I believe I will go with an aftermarket spindle to solve that. Your Lemans project looks really interesting and kinda up the alley I am looking to go right now. Simple might be better for me. What springs are you running on it? What kind of times/improvements did you see from it coming from a stock setup?

I am having second thoughts of going coilovers right now :s I dont know if a set of revalved Bilstien shocks and lowering springs might be the right thing for me?

Anybody have any suggestions regarding weather to jump on the coil over band wagon or run stock style with good shocks and lowering springs? I have a set of stock boxed lower control arms, 1.125" solid front sway bar and a 7/8" rear sway bar and brand new KYB shocks... Maybe just a set of 2" lowering springs and UMI adj uppers is good enough for a base.

Since I am leaning toward springs does anybody have any reccomendations? I have found Hotchkis, Edlebrock, Summit Brand, Belltech, BMR, CP and Global west... I like the sounds of the 2" Belltech kit from summit and its quite budget friendly as well.

Decisions decisions....

[UMI Tech]

Good morning BB. Thanks for considering UMI for your build.

The QA1 front coilover kit is super simple to install and really makes it nice to easily set ride height. You can choose non-adjustable, single adjustable (controls both bump and rebound in the same adjuster, spreads the entire damping curve in or out), or double adjustable (bump and rebound completely separate).

The rear QA1 coilover kit requires a bit of fabrication to install the top mount and brackets but is easily within the scope of most Pro-tour style guys. Once again the main benefit is ease of ride height adjustment and I can see from your signature you like the ability to manipulate your "stance".

We never got a chance to baseline our LeMans with the factory suspension and tires. Mainly it felt like a big marshmallow. With the UMI Stage 3 kit, it cornered flat, transitioned nicely and was pretty well balanced on the skidpad. Strangely enough our main problem on the skidpad was trying to stay put on the flat factory seats. This spring we plan to revisit the test track, with new seats and belts, and devote a day to tuning and finalizing our numbers. We are also going to set up an industry standard slalom and publish that info.

Our LeMans has Hotchkis 1" lowering springs with 500lb/in fronts and variable rate 124-159lb/in rear.

As for coilover vs standard big springs, we have cars on both and both have their advantages. Really, a car can work well on either.

We use a 1" diameter rear sway bar instead of 7/8" to allow the car to rotate a bit better. That's something we can address with spring selection as well.

Have a good day and thanks for considering UMI.

ramey

[CFster]

Two words: Marcus Savitske.

[clu269]

Two words: Marcus Savitske.

X2 I purchased a large portion of my parts from Marcus. He will steer you in the right direction and will help you stay within your budget if you have one.

[ProTourGSX]

Add a 3rd GS project owner to this discussion! With so many choices of brands & products available for the Buick A-bodies than ever before, just trying to narrow down to the best quality/best price options is a challenge in itself! Glad to see I'm not alone in this venture!

[UMI Tech]

Add a 3rd GS project owner to this discussion! With so many choices of brands & products available for the Buick A-bodies than ever before, just trying to narrow down to the best quality/best price options is a challenge in itself! Glad to see I'm not alone in this venture!

Hopefully we can have a fleet of Buick Pro Tour cars riding on UMI suspension all over North America!

ramey

[BBSkylark]

Thanks a bunch for all your help Ramey! I know my direction now and it was great dealing with you!

And I thought I was alone in the GS pro tour scene! Cant wait to see a finished car!

[UMI Tech]

Thanks a bunch for all your help Ramey! I know my direction now and it was great dealing with you!

And I thought I was alone in the GS pro tour scene! Cant wait to see a finished car!

You're welcome Erik. I'm sure your car will turn out great.

Thanks for the order and let me know if you have any questions.

ramey

[ProTourGSX]

Well, how long do we have to stay in suspense? What parts did you buy for the Stage 1, so the rest of us GS owners have an idea of what we'll be needing to improve suspension for ride & handling, from stock components?! LOL

After looking at the UMI website, I'm starting with:
RED Upper A-arms (to match the RED Buick 455 engine block)
BLACK Lower A-arms (to match the BLACK chassis)
BLACK Boxed Rear Lower Control Arms
RED Anti-sway bars (to represent the purpose of how to STOP body roll)

[PT Sportwagon]

Ramey, What about a PT Buick wagon? Would the QA-1 coil over kits work on the body wagon?

How about this for a Pro-touring Buick



Tim

[UMI Tech]

Hey Tim. That pic is sweet. That car has a pretty awesome stance.

And yes, the QA1 kit would work on a wagon. The cool thing about the coilover kit is it's super-easy to dial in spring rate and ride height.

I'm pretty pumped with all this Buick talk!

ramey

[PT Sportwagon]

The pict is of Todd Miller's Pro-Touring GSX. It is a sweet car. I have been doing alot of thinking of what I want to do with the suspension on the wagon. but now I have. I figure using UMI performance parts.

Tim

[UMI Tech]

The pict is of Todd Miller's Pro-Touring GSX. It is a sweet car. I have been doing alot of thinking of what I want to do with the suspension on the wagon. but now I have. I figure using UMI performance parts.

Tim

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