997gt3north

750/850 will definitely be an improvement over your current setup if you add PSS tires + also reduce the 'clicks' after the track day is over. That said, when you compare the front rate 750 to the stock 230 that is the huge change that cannot be made up for as you only have 1/3rd the front suspension travel of the OE setup.

For normal roads my 620/900 is fine with PSS tires - it is when I take the car downtown and hit a few roads that have been under construction with humps and bumps and sunken sewer heads that the car just doesn't work unless you slow way down to give the suspension time to react.

If your dampeners are 3 or 4 way adjustable then you could probably get by with a 550/750 setup and just use additional compression dampening to tweak the car for the track.

Good luck

Paul

Earlierapex

Thanks again for all the help. Anyone know if 305/30/19s (I've had good luck with potenza re11s in the past) will fit on 12"x10" wheels without issue?

997gt3north

Tirerack says 10.5-11.5

Since I think everyone here probably has it mounted on a 12 and it is out of spec my .5inch - I'm sure you could do it the other way around

Since you are looking very specifically for comfort maybe you can consider something a little different

they make a 295/35/10 - it is 1 full 1 inch taller than spec at 27.3 (i.e. a 35 profile not 30 profile tire)

if you mate this with the 235/40/19 at 26.4 it will work from an ABS issue

the only reason I'm suggesting this is that you are running much higher spring rates and thus the tires that are 1inch taller that spec most likely won't bottom out - and they will have much more sidewall for comfort - the 1 inch taller is really just 1/2 inch inside the wheel wheel so it should work - it will also give you a higher ride height when riding around town

mdrums

WAY WAY WAY to narrow of a wheel for the rear of a 997 car especially running 305. Porsche ships the GT3 with 12x19 and 305/35/19 rears....10" wide will be horrible.

Earlierapex

sorry, typo. Rear is 19*12

mdrums

Ahh...that will work...I ran 19x12 on R888 and MPSC last year and this year. Do 19x9 for the fronts and 19x12 rear running Pirelli Trofeo 245/305 and you will have a good package for 19".