Bill Verburg

1) I never impied that 993 rear suspension could be used on a 964, only that 993 fixed many areas that were lacking in 964, 996/997 further refined the process in most areas. Nothing to be defensive about.

2) heat shed from the hats is minimal, yes, alumium floating hat sare nice to have but the differences from stock aren't that great. Besides which no generally available 964 used separable hats. The compromise the factory sold was one of track suitability vs cost, for street 964 is was biased to cost for RS more to track but stil w/ a long way to go.

Tom W

I have floating rotors with aluminum hats on the Turtle. I would not do it again, I don't think it's worth the cost and effort.

ACSGP

Not sure what you meant by being defensive. Simple question, can a 964 upgrade its rear suspension by installing a 993s? I'm doing that for the engine via installing the Varioram next year as advised by Colin.

Bill Verburg

simple answer no, not easily, not so simple answer anything is possible if you throw enough time, effort and money at it.

Robert Linton

One recently retired Porsche engineer put a 993 rear suspension on his 964.

LA964RS

You can stick a 993 rear suspension on a bunch of stuff I've even seen it used on some kit cars. Just if you build a subframe to bolt it to, then things get heavy quickly.

Be interesting to see the structure the Pcar engineer used for the install.

ttAmerica RoadsterAWD

Hi Robert...have any info on this 993 rear end swap?

Robert Linton

I have just sent an email to the engineer in Germany.

ACSGP

Thanks Robert. Would appreciate if you could keep us all posted.

ACSGP

Anything heard Robert?

springer3

Unsprung weight is unsprung weight, no matter where it is distributed. You are refering to mass moment of inertia, which is lowered if you distribute the mass closer to the center. Ride and handling improve with lower unsprung weight. Acceleration is the only thing you improve when you move the rotating mass closer to the center of rotation.

Robert Linton

No word yet.

Gasser

Well, for me, I just moved from stock class to GT class and dropped around 500 pounds. I dropped 3 seconds a lap easily. Had to do a lot of last min suspension changes but once dialed in I was instantly faster. Been driving that track for years. I also use aluminum center hats/ floating rotors and I like them. Much better than the stock stuff I was using. Much more durrable.

Now Im just focusing on moving weight down and towards the center of the car. Car should be 2390 or so minus fuel. Ill have to add just a little lead for My class but that will help me corner balance the car a little easier.


I have heard of some removing their rear emergency brake stuff. Not sure how much weight this saves. I only use that brake durring transport. worth taking that stuff ouf of the rear rotor? Less rotational friction? Thoughts...


I love driving a light car, especially my 993.

FWIW

joey bagadonuts

Good data point, Gasser, and congrats on the improvement.

I was wondering if you could expand. Did the improvement come from improved cornering speeds, acceleration, shorter braking or all of the above? Or was there something else? Also, did you make other mods as you progressed to GT, e.g. slicks, cams, compression, intake, ecu, etc?

race911

I think Tom has the most developed (to a set of rules) 964 chassis car in the country now? There's some wisdom to be learned in his comments. He was all smiles after Saturday's race, even though he got nipped for a position at the end. (Not there today, so maybe even better results!)

So anyway, the Spec 911 (NOT Tom's class) field gets their trophy weight after qualifying yesterday, and most of the guys have to add 150 lbs. per the rule structure. Guess what happens during the race? Fastest guys are still fastest (Van Overbeck--yes, Johannes' dad, Gamroth--yes, the engine builder, and he had to start sixth because even though he was pole sitter they do a straw draw to potentially invert the top six starters), and the race fastest lap times are near equivalent to qualifying.