4 Kurves

I just mounted my 3rd set of MPSC's. This is how the first 2 sets went:

Set 1: Total of 3,340 miles. 6 track days, total track miles 895.

Set 2: Total of 2,425 miles. 6 track days, total track miles 845.

Both sets wore down to the same amount - through the wear indicators. Inside groove is still there (somewhat), outside grooves and slashes completely gone (slicks). From the look of it I could still use more negative camber (running 2.5 and 1.8).

The second set wore quicker on the track (I think) because as I've gained more confidence and skill in this car I've gone quicker and pushed harder.

Frankly, I'm happy with 6 track days - based upon my plans that about 3 sets, maybe 3.5 sets per year.

I supposed that I could have pushed one more track day out of them (depending upon the track) but since the next day is at a high speed track (WSIR) I didn't want to risk getting to the cords.

The wear described is on the rears - the fronts were less worn but I replace all 4 tires together.

-Kevin

JLJ

absolutely more negative camber. go at least 2.5 front and rear..i run 3 front and 2.7 rear. MPSC like negative camber with a max of 4 degrees fot this particular tire

4 Kurves

At the time the camber was changed they said this was the most they could get. Perhaps I need to to a race shop?

Viken

Kevin, you probably need to start using the camber shims.

JLJ

ABSOLUTELY

NJ-GT

4 Kurvers:

You need camber at the rear. Shims are only applicable at the front. 2.5 negative front is pretty much maxed out for the factory suspension setup. At the rear you can go to 3.5 without modifications (I did it).

Installing shims move the front tires toward the front fenders really bad. Last time I tried 12mm shims (7+2+2+1), I could not even turn the steering wheel, and I had to uninstall them immediately.

Either drilling the camber holes or rotating the upper strut mount studs (which I did) is the way to go, to prevent rubbing issues running 6mm shims or more.

macfly

I am getting about the same mileage as you did on your first set, but I'm doing more track miles, around 1,400 in a total of 3,700 miles. (However I'm around 10 seconds a lap slower than you! :-))

FWIW I'm running -2.5 all round, and getting very even wear, so based on your faster pace I'd say try -3 all round for the next set. From Feb 1st Wheel Enhancements will be set up to do full alignment work. They are also campaigning a Cup car this year to help promote theeir biz locally, and I have been really happy with the way they have looked after me when other shops have dropped the ball. If you need it done right away I'd recommend either Darren at West End Alignmaent or possibly Johnson's Alignment in Torrance as being the best places to do your set up.

NB: some shops who have the top of the line Hunter machines don't always have the experience to use them properly. I have seen a set of MPSC's corded in just two track days by improper set up from a shop with a Hunter. Having the best tool doesn't gaurantee who'll have the best user, so be sure who ever you go to is doing a lot of race prep work.

4 Kurves

Thanks everyone for the info - I agree I need more camber.

Andrew - where is West End Alignment? Closer then Torrence I hope?

Interesting news about Wheel Alignment - I may wait on them as I was impressed with the way they do things.

So if I have more camber I'll have more rubber on the road and go faster in corners.

More speed - yikes!

Viken

West End Alignment
18008 S Vermont Ave
Gardena, CA 90248-4007
Phone: (310) 808-9233

Viken

In addition, the Hunter machines have to be calibrated very often. Even more often if the alignment shop is very busy. Most shops neglect to do so.

Bob Rouleau

One more confirmation that camber shims are NOT a good idea. They push the wheels forward (increase caster) and the tires rub when you turn the wheel - even worse if you back up. Easiest is to make the camber adjustment holes at the top of the shock mount a little more oval than the factory does. It's a 10 minute job with a dremel or die grinder. I run neg 2.5 in front and neg 2.4 in back and wear is even. I can't say much about the MPSC as I used them only once. My standard is the P0 Corsa because it rains around here
I think neg 1.8 in back is too little for a hard driven GT3.

Rgds,

Premier Motorsp

Back in the old days, when the Germans bothered to design cars properly, you could adjust the camber and only the camber. Now 996s have two camber adjustments, both of which screw up everything else.

But seriously, don't GT3's have the rubber bushings with the alternative bolt hole in the front control arms? When you run a bunch of shims, you just install the bolt for the diagonal link in the forward hole. The reduces the caster back to some (hopefully correct, since it is not adjustable) reasonable amount.

I am not in favor of elongating the top holes in the shock tower. (It is shameful that the slots are even there, this kind of thing is for Camaros and such). Using the camber shims and fixing the caster with the alternate bolt hole will increase the front track, which can only help. Moving the shock top around is adjusting a great number of things, all in the wrong direction.

Somebody should mention as well that adding negative camber, with shims or otherwise, changes the toe a HUGE amount. Don't be tempted to make a camber adjustment without checking the toe.

Chris Cervelli
Premier Motorsports

Viken

FWIW, Porsche does not suggest that you stack shims to achieve the negative camber you're after. There is already a 1 mm shim installed. If that's not enough, you should remove it and use one of the bigger shims. For those desiring even more negative camber, the other discussed methods (strut rotation, etc.) should be considered.

healeyg

best solution if you know you don't want less than 2.5 neg front camber is to rotate the struts. there is another set of holes on the struts to use to do this (i believe the alternative holes are color coded and are about a 60 degree rotation - just jack a front wheel up and you will see what i'm saying). i think then you have a range of 2.5-4.0/5.0 neg.

btw - this is how the cup cars are delivered

vegasgolf98

If you are in Las Vegas (for Spring Mountain or LVMS) I recommend Kent Moore at Premier Sportscar Service. He was the crew chief for Peterson Motorsports/White Lighting (won Le Mans 2003 and 2004). He is a magician, nice guy and is very, very reasonable price-wise. (702) 649-8267
Tell him Philip recommending you and he will add 20% to the quote -Just kidding.

If you want or care what the motorsports boys are doing to solve track problems he is a great resource.

My GT3 is over there now getting tweaked after a little 4 wheel off-road action at the Track last weekend. My car is much better than the driver unfortunately.