[jhein]

Originally Posted by JLMounce

This has factory control arms correct? It's not usually possible to get as much caster out of factory arms that would cause this type of issue.

Is the passenger side wheel moved towards the front of the wheel opening at all?

Yes, factory control rms. For alignment shims, I have 2 thin shims on the front of each control arm. n the back there are 5 on the right and 6 on the left. All thin. The right side wheel is pretty much centered in the wheel well. The left side is closer to the back of the well. Is there any reason I can't just take out a shim on the left rear? Or will that throw my camber and toe in off?

[JLMounce]

Removing shims will effect all of your alignment settings. Caster, Camber and Toe.

Please measure your wheel base for driver and passenger side. It would be normal to have the passenger side slightly less if there is a road crown alignment dialed in. If there's a somewhat significant difference, this could indicate some panel misalignment, or even an out of square subframe.

Although based on the number of shims you are suggesting, I would think there's a decent amount of positive caster and negative camber in the system.

[jhein]

Originally Posted by JLMounce

Removing shims will effect all of your alignment settings. Caster, Camber and Toe.

Please measure your wheel base for driver and passenger side. It would be normal to have the passenger side slightly less if there is a road crown alignment dialed in. If there's a somewhat significant difference, this could indicate some panel misalignment, or even an out of square subframe.

Although based on the number of shims you are suggesting, I would think there's a decent amount of positive caster and negative camber in the system.

My wheelbase on the right is 107 1/8" and 107 1//4" on the left. So it's slightly longer on the side that has the wheel sitting further back. Although that difference may be within my margin of error. Interestingly both are out of spec which is supposed to be 108".

The distance from my tire tread surface to the edge of the wheel well at the very bottom (rocker panel) is 2 1/2" on the left side and 2 3/4" on the right

[jhein]

Correction to what I said above about my shims. I said they were thin but It looks like they're all actually 1/8".

[JLMounce]

Okay so you’ve got .625” shim stack in there. I don’t know how long the 2nd gen upper arm is, but that could theoretically be something like 5-6 degrees of caster. That would absolutely move the wheel backwards a noticeable amount.

Aftermarket arms that achieve those rates of caster are typically combined with a lower control arm that moves the ball joint forward to keep the wheel centered.

It’s okay that your wheelbase is out of spec. Spec would be for a car with very little positive caster. And the difference side to side is within spec for what you’d see with a road crown alignment.

Now that the spacer has been removed do you have any contact?

[jhein]

Originally Posted by JLMounce

Okay so you’ve got .625” shim stack in there. I don’t know how long the 2nd gen upper arm is, but that could theoretically be something like 5-6 degrees of caster. That would absolutely move the wheel backwards a noticeable amount.

Aftermarket arms that achieve those rates of caster are typically combined with a lower control arm that moves the ball joint forward to keep the wheel centered.

It’s okay that your wheelbase is out of spec. Spec would be for a car with very little positive caster. And the difference side to side is within spec for what you’d see with a road crown alignment.

Now that the spacer has been removed do you have any contact?

No contact now without the spacer. That made a bigger difference than I thought it would. At it's worst, the tire get's about 1/8" clearance the fender bolt but no contact. With the spacer it was making contact with the fender.

[HWYSTR455]

I'm guessing you did lock to lock checks too?



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[HWYSTR455]

Aftermarket arms make a huge difference by the way.


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[jhein]

Originally Posted by HWYSTR455

I'm guessing you did lock to lock checks too?

Aftermarket arms make a huge difference by the way.
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Yep, no contact at either extreme. And yes, I'm doing the whole suspension this spring. I'm pretty excited about that.

[twilightTA]

Finally got my PTFB coil spring lower control arms and installed them. I have it aligned at 6 caster, -1 camber and .03 toe each side.

With the SPC adjustable arms up top the amount of caster you can add is crazy high. Could easily have gotten over 8 in caster but it isn’t likely to hit the track any time soon.

I did initially have a rub after the alignment on the driver side fender with one of the bolt heads. Changed it to a button head style bolt and successfully cleared it.

The PTFB arms also stopped my issue where my tires were hitting the frame at full lock by using the built in steering stops.

My Trans Am has gained a bit of rear rake back after the front dropped a tad after the new arms were put in. I think it looks better now. Will take some pics outside after the rain stops here.

I do like how the parts decals now match between the arms, swaybars and the subframe connectors.

Next task is to try to test some different shock settings on the Viking adjustable shocks. I haven’t had a chance to really test out the difference due to the rain.

Noticed I need to paint the under side of the car again from the pics🙂

[JLMounce]

If no contact currently, I'd leave it until you do the suspension. You'll need an alignment after that anyway.

[R 70 Judge]

Looks great with the new wheels. A 2 1/2" drop front and rear would look pretty mean and would handle amazing

[jhein]

Originally Posted by R 70 Judge

Looks great with the new wheels. A 2 1/2" drop front and rear would look pretty mean and would handle amazing

2.5"? . I'll be scraping the pavement with sparks flying out behind me. But seriously, I'm going to keep the front stock height. Right now the back is too high. I think an inch, maybe 1.5" lower to give it the factory rear end squat. I know it may not handle quite as good, but it will look better (to me). In the famous words of Billy Crystal, "It's not how you feel, it's how you look." Or something close to that.

[HWYSTR455]

You have replacement leafs on the back?


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[jhein]

Originally Posted by HWYSTR455

You have replacement leafs on the back?


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Yep. This will be the second time I'm doing the suspension. I replaced all the springs about 2 years ago because the car was too low. I need a better Crystal Ball.

[vertigto]

"It's better to look good than to feel good...you look marvelous!" - Billy Crystal

[Gator67]

You could have the leaf springs de-arched. I had this done to my 70 TA to drop the rear about an inch...It ended up exactly where I wanted it, so didn't have to play guessing games...also very inexpensive and didn't seem to affect ride or handling. See before and after pics.

As an aside, surprised how long this thread is getting...lots of good information though...maybe we need a pro-touring section?

[jhein]

Originally Posted by Gator67

You could have the leaf springs de-arched. I had this done to my 70 TA to drop the rear about an inch...It ended up exactly where I wanted it, so didn't have to play guessing games...also very inexpensive and didn't seem to affect ride or handling. See before and after pics.

As an aside, surprised how long this thread is getting...lots of good information though...maybe we need a pro-touring section?

I'm surprised as well. I thought I'd get a few responses and come to a quick conclusion. Instead, you guys have contributed so much great information and have taught me a lot. As a result, it has caused my thinking about the direction for the car to evolve. So, many thanks to everyone for that.

As for the spring de-arching, that's a cool thing to know and that would be a much more economical way to go, but I think I'm sold on the PTFB stuff. I'm pretty much going all out with their stuff and I'm really looking forward to it. Should be awesome. Just doing my part to support the economy. LOL.

[HWYSTR455]

When you de-arch a leaf, you lose travel, need to keep that in mind.

A leaf can never, or should never, go beyond 'flat', if you can imagine that.

The PTFB stuff is great, hard to go wrong with that approach. I don't particularly like their' upper control arm, it doesn't appear to be rigid enough, and they don't make tubular lower control arms.

I don't like the SpeedTech ones either, they drop the car too low, and don't accept double adjustable shocks. They are more made for hybrid coilover conversions.

The Global West are the best, even if they are on the pricey side. My understanding is they have the best geometry. If you buy these, you never have to consider ever buying any other, and they last a life time. The powder coating on them is the best I've seen on any.

I have no experience with the QA1 arms, but they are so close to the cost of the GWs, it just makes sense to get the GWs at that point. BMRs, same thing.

I have had a number of issues with the CPP stuff, refuse to buy their' stuff anymore.


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[HWYSTR455]

The GW CAT 5 springs are the best on the planet, and they have reverse arch ones too.

The reverse arch ones you have to call to order those, and there may be a wait for production.

The 'regular' CAT 5, the last spring wraps half way around the forward spring eye, and the second leaf is long in the front section, making it so there's no need for any traction devices.

Again, the best, but on the pricey side.


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