AJM54GT3

When I bought my car I had the dealer put on a set of MPSC's and set the alignment.

I just checked it myself (thanks Longacre) and am showing front left 1.0 and front right 1.3. The toe shows 1/16 toe out. I have shims. The question, to avoid as much trial and error as possible is what thickness of shim should I add? My suspension is stock.

On my former 996 that had a full GT3 suspension I ran 3 degrees front and 2 degrees rear but I dont recall how much shim I used. Thoughts? The car is mainly a weeekend and track car so I want max grip and am not too concerned with tire wear.



Thanks. Alex

va122

Rotate the strut tops then add shims to taste.

AJM54GT3

Rotate side to side or 180 degrees?

Thanks

atr911

You remove the studs and change their position (it's pretty clear once it's out).

This will change your caster as well. With all these changes you're making, your toe will be WAY out. I'm assuming you can adjust/change it yourself but if you can't be prepared to trailer the car.

I did not rotate my tops and ran a 16mm shim (not available from Porsche, try Tarett). I had about -3.2 front.

When measuring alignment, be sure that your tire pressures are set appropriately and that the tires have even or not wear (new tires best).

Have fun!

Adam

GT2rainge

With rotated strut tops in cup position and 7mm bottom arm shims my car now has minimum 3deg neg camber,and the castor is where it should be around 8 30.
Its the best way to do it in my opinion,cheers

mooty

Rotate as suggest

However -3F/-2R u had on c2 which I presume u will use on
GT3 will not provide max grip but just a loose car. Furthermore with
That much front camber u will never get enough heat in the rubber for weekend drives to get any real grip with mpsc

911SLOW

Alex hi, you could use the search function this issue comes out every other week and here there are tons of great info including settings sent to members from Porsche motorsport.

+1 Rotate and add shims and then have a proper alignment.
Also invest in some better rear toe links to hold it.

3F 2R works for me even for weekend driving, but I run 315s rear and 888s which need about half a corner to get to temp.

With MPSC and rears 315 (when still available) 3F 2R worked again for track and for my driving style.
But when I was brave enough to use them on the street it didn’t, as Mooty said they want heat to grip and they were tough to get it on the street. And you don’t even want to know how they drive in the rain.

If you only care about track performance with the 235 295 cups you have, go F 2.4 to 3 and R 2.2 to 2.5.

If street weekend driving is the primary target then aim for lower C numbers. But then again why you would choose MPSC for street?

BTW shims are available from Porsche Motorsport and Gert has them : http://www.carnewal-europe.com/cpx_p96154.htm

John

AJM54GT3

Thanks for all the suggestions.

After reading this forum and talking to some serious GT3 racers I decided that 2.5 negative camber in the front running MPSC's is ideal. A long way from my SpecE30 race car that LOVED more than 4 degrees of camber.

My GT3 started with 1.0L and 1.3R negative camber with 1/16 toe out.

I started by moving loosening the three nuts on the strut tops and slamming them to full negative camber. I then added 3mm of shim to the lower control arm on each side. This gave me 2.5(sometimes you get lucky) on the right and 2.2 on the left side. I addded an additional 2 mm of shim on the left for a total of 6mm. After playing with the position of the top of the strut I got 2.5 on the left also.

This left me with 5/8 toe in. I adjusted the toe links to 1/16 toe out and then moved them both in sync to get the steering wheel straight on center.

The car has a lot more front grip and is almost neutral running 55mph around a seldom used traffic circle near my home.

Next up is the rear. I am currently showing negative camber of 1.8L and 2.1R
and 1/4 inch of toe in. My plan is to bring the rear up to 2.4 degrees.

The point of this exercise is certainly to get the GT3 handling better but the real purpose is to get to know the suspension in a 966 and learn how and what works. In November I am buying a 996 Turbo with the idea of turing it in to a monster 650 plus hp race car. If anyone knows of a great cage builder in the North West AR area please pass along contact information.

Also, since most Turbos came with sun roofs, I am thinking about losing some weight (45 lbs) and gaining some head room by putting in a GMG Carbon Fiber roof conversion http://www.racperformance.com/index....MGAerodynamics has anyone used this product and if so, what were you charged for installation?

Thanks. Alex

AJM54GT3

To answer a pm, I am not selling the GT3. Just adding a turbo that can be morphed in to a race car.

I run MPSC's on the GT3 because it only gets driven 6K or so miles a year and never in the rain. New tires once a year has not been a big deal. As I live 30 minutes from the Ozarks ther are lots of beautiful, traffic free drives on very twisty roads with serious elevation changes.

If anyone has a Cup deck lid and wing, please let me know....