I ran my 997C2S at the DE at BIR last weekend. Only modification was Cup tires on 18 inch wheels.
The 997 has stock camber. Is the GT3 camber and toe in the same as the 997S? Is the GT3 more track specific (i.e. negative)? Anyone used the GT3 specs on a 997 to improve performance and tire wear?
I also heard that the 997 can be lowered 10 to 20 mm by adjusting the suspension? Any validity to this?

 

Hmm... Lots of threads on these subjects. Do a search on things like alignment control arms camber, corner balancing, etc. at the 997, 997 GT3, and Racing / DE sections.

Here's a general summary from what I've learned at these threads (I had the same questions):

Stock camber can be adjusted to about -1.0 front and -2.5 rear, though the front at -1.0 will set the rear to about -1.5. You can get more by putting in 997 GT3 Cup lower control arms (about $1300 parts, labor and new alignment) which will get you to about -2.0 and -2.5 respectively.

Farnbacher answered my question about lowering the stock PASM suspension - Don't do it, shocks are not valved for it and will blow out over time. I've read about some failures already. If you want to lower and adjust, you need a PASM coil over system, like a PSS9, which just came out recently. Otherwise, no, you cannot lower the stock suspension.

What may make sense at this time is for you to have a race shop give you as good an alignment as you can - my dealer charges $250 for a full-blown session with their Hunter. That should get you to -1 and -1.5. If your car is new (under 2k miles), you might be able to get a new alignment under warranty because the 997 products are notorious for coming with bad settings from the factory (I got re-aligned at about 1k miles - 2k is the limit).

 

The GT3 is totally adjustable, your C2 isn't. YOu can have your camber and toe adjusted (within limits) but that is about it. As for ride height, corner balancing, etc., you can't.

If you want to lower the car you will need to change your suspension bits. Namely shocks and springs with a coilover system like the GT3.

 

I'm glad I found someone that agree with me on this subject! I asked around too and the bling bling crowd will argue about lowering with just springs on the stock PASM shocks is ok to do...but my arguement is that the stock PASM shock are not designed to work in the compression the lowering springs put those shocks in.

 

Dakota, heck out this thread:

https://rennlist.com/forums/racing-and-drivers-education-forum/344551-997s-alignment-for-de-autocross-and-street.html

I just went through having my Carrera S aligned with autoX and DE's in mind but still being driven on the street.

 

I had an alignment done yesterday. Here's what I got.

Front camber: -2.2
Rear camber: -2.7

 

-2.2 Front on a C2S?!? Do you have GT3 lower control arms?

 

No.

The tech was able to get that much by slightly elongating one of the adjustment holes on each side.

I didn't get into specifics with him but he has been doing it for years on 996s without any problem. If you want to know exactly what he did I can ask him this coming weekend.

 

Please do - a DIY type instruction on elongating the lower control arms to dial in more camber would be very helpful to many. $1300 for replacement arms vs. $100 for an hour of labor to modify the existing ones.

 

hmmmmm.....
I don't necessarily agree. PASM shocks are no different than other shocks in the way they work, only than the valving is adjustable electronically.
The point (suspension travel) at which the shock runs makes little difference. Wha't problematic is bottomming out, where the shock is subject to severe impacts (somewhat dampened by bumstops) more frequently when the shaft reahed the end of its travel. Good lowering spirngs are generally proegessive and very stiff towards the end of the travel, therefore preenting somehow the frequent (and potentially) damaging bottoming out scenario.

Irrespective of what springs you use, if you track your car, your PASM shocks will wear faster than normal, as any other shock used on track. So IMO there's little difference if you use stiffer lower springs or not.

IMO, the stiffer lower springs are a much better match for PASM in Sport mode where the regular OEM springs are seriously overdampened (hence the jerky bounce on the street). I see no point in owning a new car that you take yo he track beynd the warranty period, and if anyhting the PASM shocks given their adjustability are built at better tolerances than a common shock, so they should last Ok through the warranty period with proper lowering springs or OEM ones (unless you drive your C2S, 4 up all the in New York City)

 

Known mod. Important to note that he's pulling in the tops to create more negative camber in lieu of pushing out with the bottom control arms. Net result is more camber, but without the added benefit of a wider track...

 

hmmmmmmmmmm......like I said it is good that I found someone else that understood/agreed with my thoughts on this subject. I know you do not agree like many many others on here.

Yes it does matter a lot from my talks and understanding with those that know the current Porsche 997s PASM shocks on where they run with lowering springs.

 

For a pretty much stock street car this method made sense for me. When I get around to getting a dedicated, no compromise street car the solution will likely be different.

I kept wearing out the outside edge of the tires on the driver's side. Tread was fine but the shoulders were down to the cords.

We'll see how this works.

I realize on the street I'll see more inside tire wear.