Hams955

If you're near Ft. Myers you should reach out to John Gaydos at Autoquest Motorsports. He's a great guy and can help you with getting the car dialed in. Tell him that Chris Hamilton referred you.

Kind regards,

Chris.

AutoQuest Motorsports

Why thank you Chris, I appreciate you saying so : )

Nice to find another local! We know the 991 GT3's very well and Sebring is our home track, we are there most every event and run the Suncoast DE events. Give me a shout at 484 883 6197. We'll chat about your car a bit, and we can dial it in with our tailored chassis setups for Sebring. We also have harnesses and roll bars in stock for the 991 GT3, and would be more than happy to do the install. You can replace cars, you can't replace people. We also support all our guys at the events we go to so you can pit with us, we'd love to have you

Earlierapex

AutoQuest Motorsports

We've had bars paint matched before, I don't see any reason why we can't do a Sapphire Blue one

Manifold

Use factory alignment, messing with it doesn't help much in this car, and changes could make it worse. Use Cup 2 tires, around 32 psi hot. Cantrell is a good roll bar.

Earlierapex

Thank you. That's the target pressure I've been running, works well.

With the multilink setup (and maybe RWS), I can see how negative camber might be less important in the rear, but how is it possible it wouldn't help in the front? I find that hard to believe, but I'm old enough to know there's a big difference between theory and data... Any data on stock vs. max camber alignment head to head?

Anyone have head to head data with and without a DSC controller for PASM? Does it help?

Manifold

With the suspension setup and PASM, the car doesn't roll much in cornering and there isn't much camber change. Apparently, the factory camber of 1.5 to 2 degrees is enough to make proper used of the tread in cornering, and keep in mind that the sticky rubber of the Cup 2 is in outer third of the tread. Too much camber or tire pressure will move the contact patch away from the sticky rubber, and could also adversely impact braking, as well as the transition from braking to cornering.

Lots of track guys played around with the setup of the car during the first year or two after it came out, and experienced showed that there wasn't much or anything to be gained by messing with the setup; a possible exception is a setup with big cambers and other changes, but that setup isn't practical on the road. A pro shop I've worked with also told me that they spent a lot of time working on the setup, and concluded that not much can be done to improve on the factory setup (owner of the shop is a pro racer who owned the car himself).

Earlierapex

But won't the crazy castor angle required for more camber fix the braking?

Makes sense. Thank you. Sounds like it's not worth it unless you move to Hoosiers or similar, which tend to appreciate more camber. Plus more grip = More Gs = more roll = more negative camber = stiffer springs = more $$$

How can an enterprising entrepreneur make a small fortune in racing?

WheelsB

Manifold

I'm suggesting not changing the camber at all.

If you go to Hoosiers or slicks, the higher grip could necessitate numerous changes, as you note. But keep in mind that doing that could also void the warranty, and the 991.1 has the extended warranty for the engine. Some have argued that the Hoosier is a DOT R-comp tire like the Cup 2, but it surely has more grip, and the car does have a G-meter.

gmgracing

100% agree with this statement.

mdrums

Michelin highly recommends hot pressures from 34-38 front to rear depends on car, alignment and track. They also say DO NOT go out under 26 psi....keep psi higher and bleed. I see guys chunking MPSC2 tires and Michelin was asked about this and its because of too low psi.

I took there advice and used a -1.5 camber from and rear and it's working...no tire issues at all pretty even wear. I am running 34psi front and 36 psi rear. My rear will shoot up to 38psi but still no much of a problem just a little looser rear.

Manifold

Lot's of data was gathered on this here on RL, and I believe the median value of the optimal hot pressure was about 32. Some people indicate as low as 29-30, and others as high as 35-36. I personally found 32-33 to be about right, and I have about 7K track miles in the car with the Cup 2. I don't start out below 25-26, usually start around 27-28, and don't start to really lean on the car until the pressures are about 29+; I also don't overdrive the tires when it's evident that they've become too hot and greasy. With this approach, I've had little to no chunking.

My starting pressure means that I'll be way above 32 by the end of the first session, but I just continue to bleed off through the day as needed.

Earlierapex

I understand and appreciate the advice to keep the alignment stock, but just for giggles does anyone have direct experience with the wear patterns when running more camber with MPSC2s? My experience is that I've got -2.2 up front and show clear additional temperature deforming wear towards the outer edge of the shoulders (actually front and rear). Starting pressure of ~28psi, hot pressure of about 35-36 or so.

Manifold

You see a line near the outside edge where the wear seems to be too fast, but this turns out to be of no consequence, since the wear pattern evens out as the outer grippy part of the tread continue to wear.