ArcticFox

Hey all, I am hoping somebody (maybe some of you racers) have any insight on how to adjust the non-adjustable caster setting on the 996 GT3.

I have seen no adjustable upper strut mounts on the market for the car, and my search here came up fairly empty too.

Can anybody share any ideas or sneaky ways to adjust the caster, asside from the 1mm adjustment you get on the car already (haha).

I am aware that the 997 Cup arms may provide an answer, but if that is a fix, I would like some feedback on those who have done it before I make an ivestment in those.

Feel free to PM if you wish. I know that some of you race and would liike to keep your secrets to yourself. I will keep all PM's confidential. Promise!

Thanks in advance...

ArcticFox

HAHA. So what.....there is no answer....no solution???? haha. Or are you trying to keep a secret? Hmmmmmmmmmmm.

Bob Rouleau

Fox - it depends on what you want to do. If for example you add negative camber by rotating the struts, you add caster by using shims in the lower A arm. Note that too much caster causes rubbing on the fender liner. Does this help?

LVDell

Depending on what camber settings you are after, have you thought about rotating the struts AND adding shims???

ArcticFox

OK, here's the story.....

Last year, I was tracking a lot and wanted more camber. We flipped the hats and all was good. This year, I knew I would have little time for tracking so I had the alignment set back to stock. They flipped that hats back and could not get it within factory spec - camber or caster. Thus, as I am finding out now, they left the RF hat flipped so they could get hte camber within stock spec AND get it to match the LF. Apparently, the caster was out a bit.

The car pulls a bit right, and I am told this is caster, as camber and toe are spot on. I am also told that if we raise the ride height, we may be able to get it to come in, but I dont really want the car higher.

So.....I am looking for a solution to get the fricken RF caster to match the LF. The pull is annoying as hell. It is amazing how sensitive the car is to even slight differences in caster, etc.

ArcticFox

My mechanic thinks this may work. He said it does have some adjustability to it (the holes in it). Thoughts?

Bob Rouleau

If you rotate the struts to the original position AND remove shims in the A arms you are back to stock. When you rotate the struts you get the negative camber you want but good shops will add shims to bring the caster into spec, i.e., more caster.

If the caster is even on both sides, I don't think it would cause the car to "pull" to one side unless you are on a crowned road.

If there is not enough caster, adding shims in the lower suspension arm will increase it. There is also an adjustment as you have described above to increase caster. I have not used it so I cannot comment.

ArcticFox

Thanks for the comments!

The caster is NOT even on both sides. Maybe I didn't convey that earlier. That is the reason I am trying to figure out an adjustment for it.

Apparently, when I took it in for an alignment last week, they were unable to do the alignment properly because the RF strut hat was "flipped". The shop flipped it back to stock and returned it to the alignment shop (he was too busy to do it himself). When he tried to align again, he was able to set toe and camber at stock, but the caster was wacked on the RF. Thus, I am trying to figure out a way to adjust the caster.

I did mention shims to my shop and he said there really wasn't room for one? Note sure about that, but my guy does lots of P-cars and is deemed by many locals to know wtf he is talking about. I will be in contact with him today to have him address the shim issue again, so i understand why that is not going to work.

I was hoping that somebody made an adjustable hat for the car....that would be nice! But I cant find one and believe they do not exisit. Although, a friend of mine who is in that business says he is going to make one...so time will tell. He is so damn busy with 10,000 other projects that i doubt this will happen anytime soon (also due to the potential (limited) number he could sell).

Bob Rouleau

Fox - I think you need to find a more competent alignment shop. The lower A arm of a GT3 is split and designed to allow shims to be inserted. Said shims increase negative camber and at the same time increase caster. Caster is not very adjustable on these cars excep with shims and the additional hole. If it is uneven, then: there are shims on one side and not the other;
The A arm was moved to a different hole to increase caster (without shims) on one side but not the other (my best guess as to what happened). Without taking the arm apart this would not be visible just by looking at it. If it was moved on one side but not the other it would explain your problem.

best,

ArcticFox

Many thanks for the comments Bob. I will look into it!