Newbe Front Suspension ??'s - Second Gen F body

[KTrostel]

OK, I have looked through the posts, and gone to the vendor sites but have been left a little let down interms of content - So here goes

I have a 78 TA, I have already welded up the stock front sub frame. Ideally I would like to use the AFX tall spindles (checking on availability) with good tubular upper and lower control arms. Short of that, I would substitue Howe tall ball joints along with good upper and lower tubular control arms. My problem is the control arm vendors that I have looked at - SC&S (globe west), DSE, Guldstrand, and Hotsckis, none come out and quantify the camber gain or bump steer correction. All say they have increased camber gain and decreased bump steer but to what extent. I find that it is impossible to measure one against the other without some quantifiable values.

Any insight would be greatly appreciated.

Kurt

[XcYZ]

Welcome aboard, Kurt.

Those are great questions. And as far as being quantifiable, do you know the camber gain of the stock suspension setup (at a known ride height) for the benchmark? I don't know those numbers and I think this could be a great thread for getting that data posted.

Bumpsteer can be measured and dialed down to a minimum with the right tools (barring any major issues and crazy low ride height). I've done that on my car using a Longacre bumpsteer gauge and a set of Baer Trackers.

[KTrostel]

Thanks for the help with bump steer.

As for the camber gain, it is my understanding there is no camber gain with the original design. Of course that is a gross average not a precise measurement.

Anyone ???

[Blake Foster]

No tubular control arm (that i know of) is going to change bump steer. unless the arms are shorter or longer, as for camber gain the only way to change it is to relocate the control arm mounting point (guildstrand mod on first gen)or the ball joint pivot location so tall ball joints or ATS Tall spindles. you would never know the differance on a street driven car.

have a look at our arms, i noticed you missed them in your product search

http://www.speedtech-performance.com/index.cfm/page/ptype=product/product_id=57/category_id=187/home_id=187/mode=prod/prd57.htm

http://www.speedtech-performance.com/index.cfm/page/ptype=product/product_id=58/category_id=188/home_id=188/mode=prod/prd58.htm

here is a pic of one that we did with the complete set up

[KTrostel]

you would never know the differance on a street driven car.

Ultimately I would like to take the car for some track days.

Thanks for the link. Tell me, do you offer a package with coil overs?

[Blake Foster]

we offer the QA1 coil over conversion set up.and in the package there is some monry to be saved.
give us or one of our dealers a call.

[pro-tour79]

as mentioned the A-arms themselves will not change bump steer or neg. camber gain unless the pivot to ball joint points have been changed and the length of the upper arms has been changed, remember that second gns already have "tall spindles" no real reason to change them, we have a Comp upper control arm and tall ball joint that will correct most of the second gen's short commings, the second gen has very good geometry to start with and only needs small changes to make it better.
The stock lower arms can be retained but should get solid bushings, either Delrin or sphericals but should get some welded braces to limit flex we do have a new lower control arm that is designed to limit flex, has 2* built in caster and saves 3 lbs over stock.

[Cread01]

I have a 78 camaro and am currently doing some of the same things. I went with the qa1 coilover setup, the scandc stage 1 kit with the howe tall upper ball joints tubular lower control arms and the true steer kit from pro-touring fbody. there are tons of options out there and I looked at them extensively to get what I wanted.

For me alot of it went on what I could get in my budget and what I liked about certain products. I really liked the spc control arms because of the adjustability without shims but they do have an industrial look. personally I like that about them. SCandC.com is a sponsor here and marcus is extremely helpful and knowledgeable. Dave at protouring fbody was also extremely helpful he is a sponsor here also. That is not to say it's the best option for you just the way I went. That is one of the best things about this site is that you can talk with alot of the vendors and they are usually very helpful.

If I would have known that killer customs would give a package with control arms and coilover's I may have went that route to save some bucks also.

If you do a search on nastyz28.com there are tons of posts about what other people have done on there second gen's and that may be helpful also.

[BonzoHansen]

...we do have a new lower control arm that is designed to limit flex, has 2* built in caster and saves 3 lbs over stock.

Dave showed me one of these over the weekend. Nice. The added caster is a plus. I run 6* in mine and I get some rub in the RF.

[KTrostel]

Great info. I will definately take a look at these suggestions.

[Hotchkis]

As a few others have already said, the 2nd Gen already features drastically improved geometry compared to the 1st gen cars. Our new Hotchkis 2nd Gen Lower A-Arms (http://www.hotchkis.net/7081_camarofirebird_tubular_lower_aarms.html) feature repositioned ball joints for increased caster and improved camber curve. Our arms also have a CNC cut billet spring cup that's integrated into the structure of the arm and fully TIG welded for improved rigidity to prevent deflection.

Hotchkis 2nd gen Tubular Upper A-Arms (http://www.hotchkis.net/7081_camarofirebird_tubular_upper_aarms.html) increase caster and camber gain and the offset cross-shaft allows increased static negative camber without a large alignment shim stack.

Here's a video of an '80 T/A with all our parts (TVS, Subframe Connectors and Upper/Lower A-Arms) in action during testing at California Speedway.

rtCbzhTAilM

[pro-tour79]

so, I see "increased camer gains" are the A-arm lengths altered?

[B_Alley]

You could also increase Camber gain (in bump) a number of ways with the upper control arms too- shortening or lowering their inboard pickup points. It becomes more complicated when the car goes into roll, but more caster will also help your camber on the loaded tire...

[Hotchkis]

We move the upper ball joints back for more caster. We also shortened the upper arm for a quicker camber curve. We lengthen the lower arm slightly for more static neg camber and less arc during travel. This combination produces excellent neg camber gain as the suspension travels up.

With stock upper and lower a-arms, we are barely able to get -0.5° of camber and +2° of caster with shims maxed out. With our Hotchkis A-arms, we can easily get -3° of camber and +6° of caster with room to adjust.

For street applications, we typically set up then 2nd gens with (-1° to -1.5°) of camber and +5° of caster. For autocross or track we set the camber anywhere from (-2° to -3°) and (+5° to +7°) of caster. These settings vary based on the current modifications that are already done on the car.