I ran into a problem with installing the GT-3 lower control arms up front on my car. Everything seemed to be ok - I could get up to 14 mm shims in place, and could get -2 deg camber from that, and another 0.5 or so from moving the tops. When setting up the car for the track, I was checking the sway bar adjustment, and I found that when the wheels are turned, they rub the front fender wells. A lot.

I noticed that there were two holes in the outer part of the control arm in the middle. One is in the center, the other is slightly offset. The originals had only the one hole in the center, so that was what we used. Should we have used the other one????

I think that I can make the car drivable by removing some of the shims, but then of couse I lose the camber I put them in for. I know several of you have made this mod without this problem - Anybody know what to do?

Thanks,

Jon

 

Jon, I'm using PSS9s with my setup and I'm at lower than GT2 ride height. What my shop did (I installed them and then they set it up) was leave the thrust arm in the center hole on the bushing. We have a total of 13MMs worth of shim in the control arms and I'm running MPSCs with no rubbing. I'm on the stock sizes... I drove the car two weeks ago at the track with the stock wheels/tires which are even a bit taller and had no issues, and I've driven the car a couple of times over the last two days looking for leaks, and I only have rubbing at full lock on the inner fender linner up front...

You're upper strut mount might be part of the issue, and swapping to these may help: http://www.vividracing.com/catalog/m...5-p-52995.html


They'll allow the strut to be at a better alignment and also allow the more severe angle inward without bind... I have a pair that I plan to instal in a few weeks.

Mike

 

Mike -

Thanks for the feedback. I have those upper mounts already, and am also on PSS9's.

I'm going to pull out some shims today and see if I can minimize the rub. If I can get it so it's only at full lock, that would be ok. My gas tank is also almost empty at the moment, so a full fuel load is only going to make this worse. I'll keep ya posted.

Jon

 

need to adjust caster.

 

I pulled out the thrust pin and looked at the control arm. The other hole would move the wheel even further forward. Is there any other caster adjustment?

Jon

 

do you have solid inserts in your GT arms or do you still have the rubber?

 

oak, We both have stock rubber bushings on the GT3 control arms...

Mike

 

look into solid inserts! you will thank me.

 

Here's the issue...

Solid inserts correct the mount point at the Conrol arm... I saw SIGNIFICANT compliance issues when I installed the control arms, at the SUBFRAME mount. Npt sure I think the "at control arm" fix fixes the issue...

Mike

 

mike, you can compensate the pick up point angle with the solids.

back when you were inquiring about suspension mods I suggested it might be prudent to do all these mods at one time so you can dial it all in at one time. as opposed to trying to piece meal you will have to take apart and reinstall and re align everything every time you change something. not worth it unless you are going long stints between mods.

 

Oak -

Thanks for the lead. I will look into it. From my view of it yesterday, I don't see how changing that bushing could move the control point. The thrust pin still has to go through the control arm in the hole provided, and the bushing doesn't change that. Do you have a photo of the setup you're talking about?

For the moment, I found a compromise with reduced number of shims that doesn't rub. Given that I am leaving for the track on Thursday, I think that I will go with this for now and get the whole thing dissected when I get back.

Thanks for all of the comments.

Jon

 

Welcome to my "recent" reality. I'm having to do things piece-mill because of a lack of funds lately. To add more insult to injury, the damage caused by the ontrack incident, and then the further damage done by the impact in the car trailer, has now set me back financially enough that I'm thinking about pulling the plug on my own 996TT tracking...

I do have another plan, of course...
Mike

 

bummer mike, sorry to hear about that. believe me I know about piece meal, I purchased my new suspension in the same manner, but decided to install all the parts at one time.

don't ask about the install that was somewhat of a nightmare. I am still in the process of cleaning up after having two separate shops do the install.

 

Reality set in this week when I looked at my track car sitting there, no attention to it, all my fun money diverted to improving the 996TT, and now fixing it, and the track car could be just as much fun with so much less work... So I'm pretty sure that this will be my last track weekend in the Porsche, unless I absolutely have to run it while sorting some issues with the other car... I'll get it repainted to get the rock chips/ imperfections from track use cleaned up/ painted and more clear bra installed, and I'll drive it on the street until I'm done driving her...

Mike

 

Nah, I don't believe it. I feel that way when the mods go wrong, or worse, when the car breaks at the track. Then you go out and have a blast weekend, and you change your mind. These cars are just so darned fast, and relatively easy to drive. I once saw a great T-shirt that read:

"Racing is the efficient transformation of money into noise"

Jon