ScottL

On my previous Porsche (996RS) MPSC's were magnificent. 90% grip of a slick whilst remaining road legal.

I took delivery of a 08 model year RS in September. My car came on the new 19" N rated Pirelli Corsa System.

I'm running with 3 degrees negative camber all round and a touch of rear toe. Everything else is standard.

Been on track 3 times and I've found the front handling balance is chronic understeer whilst the rear is ultra stable and composed.

The Corsa's are only 50% worn but today I has a new set of Cups fitted. I went with the original design on the front (as fitted to BWM CSL's) and the Porsche rated 305 on the rear.

I'll report back in due course how this influences the handling balance. Next trip is to the ring on 8th and 9th November but might squeeze a UK circuit in between now and then.

Some questions...

What are peoples experience with the front and rear anti roll bars? Euro cars come with the rear full still and the front in the middle setting. Has anyone tried going one stiffer on the front and one softer on the rear?

I hear US owners talking about Hoosier tyres. We can get these in the UK although I've never seen anyone on a trackday with them fitted. What is the preferred sizes for a 997GT3/RS? What about wheels? What are the experiences with this tyre? How does it compare to a MPSC?

Any other wisdom on getting these cars handling sweetly on track much appreciated.

Thanks,

Scott

997gt3north

Scott,

- the direction you mentioned with the sways will make pushing worse not better
- leave the rear full stiff, soften the front to one from soft or fully soft
- if you have steel rotors, order a set of 18" rims (search the rennlist boards for the fit you need) and then run 245f, 315r hoosiers for trackdays
- given that you are in the UK (weather?) if your trackday looks like the weather wont be great run the stock MPSs or PS2s

- also, i would reduce the rear camber to -2.1 to -2.2 from -3 that you currently have to free up the rear end a little plus it will also dramatically increase tire life

- my 20 day track experience with the car has lead me to the following setup for the Porsche OE MPSC tires (or the 235 real cups on the front)

- front = -2.7, rear= -2.1, front total toe 1/16 to 1/8 toe "out" (this helps alot), rear toe in as per OE specs

- if you go with with the (245,315) Hoosiers on 18" rims for trackdays, less front camber will be required and a little bit more rear to balance the car plus you will be able to run zero front toe or slight toe in

- the car's pushing is most noticeable in slow to mid speed corners but not on highspeed sweepers so depending on which tracks you are setting the car up for the setup i mentioned above is my current best guess for the OE tires where there are 60 to 70 mph 90 degree turns that must be negotiated

- also, i found that it is very important on these slower turns to trail the brakes as long as possible to the apex and beyond to keep the nose down to get it to turn

- that said, Hoosiers really do transform the car and increase grip tremendously

ScottL

Very informative - thank you.

My car has ceramics so I was looking at the 19" Hoosiers. Tirerack lists a 235/35/19 but no 305 for the rear. The choice is 295/30 or 315/40. Whaddya reckon? Any ideas as to suitable wheels?

Forgetting the Hoosiers for a moment...have you got to a handling balance you are happy with on the OE MPSC's? Some drivers over here are blaming the active dampers for these handling issues. What are your thoughts?

eclou

The 295 Hoosiers are probably wider than the 305 Pilots.

997gt3north

-pretty sure it is not the active damping but the tires - like 90%+ sure
- got a ride in a car with 18" hoosiers on a track that really exposes the pushing nature of the stock setup and all i can say is that you would not believe the difference - it is like two totally different cars
- i say 90% as i do believe that it is possible that the rear suspension is undersprung which causes the nose to lift of tight corners with throttle application but 90% plus of this is corrected with the correct rubber - the last 10% is cupcar type suspension changes
- i haven't driven the hoosier 235/295 setup so i can't comment - i can only say that the 245/315 setup in 18's is amazing
- you can fit 18's over the pccbs, i have personally seen two cars with this setup so i know it is doable
- i suspect that next year there will be more choices in 19" rubber but i am very convinced that the front of the car needs more rubber, i.e. 245-265 and that is what i'm working on now
- i will be fitting 265 mpscs in 19s over the next few weeks as i want a solution that will allow the car to be driven to the track and i think this may be it - that said there is no doubt the hoosiers have way more grip
- phone one of the american tuner shops that have fit custom 18s (hre, filkse, +others) have all been done

ScottL

Sneaked out at the end of the afternoon for 20 minutes on the Silverstone GP circuit today.

The "real cups" were a definite improvement over the Corsa's. Looking forward to tweaking the geo as discussed above to get the front working better still.

I also ordered a set of Hoosiers and some Champion RG5's (8.5/19 f, 12/19 r) to put them on. I went for 235/35/19 front and 293/30/19 on the rear. Really looking forward to trying them out.

I drove a 360 Challenge car on slicks a few weeks ago and it was a fantastic experience. How do the Hoosiers compare to a full blown competition slick?