TB993tt

Noticed Michelin have made some tricky new MPSC N rated tyres in 245/35 to fit the 9" fronts which come on the new GT3RS.

The rear RS wheel/tyre/offset combination is the same as on the GT2 - If one has 9" fronts on the GT2 (currently wearing stock 235/35 MPSCs) would there be any downside to fitting the new 245s ?

pmf

Hi Toby,

The 245 will actually fit better than the 235 if you have 9" wheels
Only thing, if you lowered the car check the clearance to the fender, as the ratio of the tyre is changing of course

I am actually experiencing some understeer, so I really look forward to get rid of current crappy Corsa to try the new 245 MPSC

One question: FWIK, the rear 325/30 MPSC are rated + N0, the front 245/35 are rated + (not N0)
I actually do not know if this will make a difference, i heard everything and its opposit about N0 rating (I even heard that N0 rated tyres have softer shoulders...)
What do you think?

Ciao
Paolo

NITEALB

I'm considering the same thing. the corsa's are crap and the hoosiers are too compromised for street driving. would like to try these tires to see if they make any difference to lap times.

stout

New RS gets the bolt-on flares with the 245s, but I suspect they'll fit under the stock fenders. In the days of the 996 GT2, a local had 265s on 10s up front and the car worked brilliantly (thanks to a lot of other suspension work, as well). 911s can "always" use more grip up front.

That said, I'm not sure the 997 GT2 is a car I'd want to start messing with the handling on. That's one car I feel Weissach got really, really (really!) right from the get go. Personally, I'd be working on my "grip" on things for a long time before messing with the car...

YMMV!

pete

Z06

I thought the front stock size rim was a 8.5 on the GT2?
Even though the 245 will fit the 8.5 rim...you would just have to check the diameter

Z06

I have pulled 1.65 cornering G's with the full tread stock MPSC at Mosport on a 1.31 lap... with the Hoosiers so far 1.67 G's also a 1.31 lap this using the Traqmate GPS... also did 155 MPH.


My suspenison is not stock, it has very, very mild understeer which I chose not to dial out...It will go a 1.29 at Mosport if not quicker.

Bob Rouleau

Check the rolling diameter of the 245's. On the new cars (those with 19 inch wheels) Porsche has recalibrated the ABS (and probably the PSM and TC functions) to deal with different diameters front and rear. This opposed to the older cars running 18 inch wheels which had rolling diameters which were identical or close to identical. A local put 997 GT3 tires on his 996 GT3 and got ABS problems (it intervened even though it was not needed) because of the difference in diameters. Be wary.

stout

Bob: So, could the GT2 computer be reflashed to use 2010 RS ABS parameters if the above won't allow for the diameter difference?

pete

Jon70

I thought the ABS parameters would allow for a 4% or so difference before activating.

fc-racer

Wow, a 1:31 in a street car, impressive!!

Z06

The GT2 and the new RS will have very similar diameters and it will not be a problem...they have gone with taller tires for more grip.

Z06

It's a great car, it took a little bit of getting used to the HP & TQ and that massive cornering grip..sub 30's is not far away.

It's braking at 1.3+ corners at 1.6+ g's

TB993tt

I've got 9" Dymags so I guess the fit would be good, as excmag says this car handles so right that I am reluctant to mess around in this dept....