DrPeter

Just got a new set of narrowbody GT3 wheels 8"x11" with Bridgestone SO2A N3's on MY04 996 with x74 suspension and I am experiencing much more understeer (no track use.) Apparently this setup changes the handling characteristics on several levels with regard to increased weight and increased relative rear width. There is not much retrievable information on 8x11's with the search function. 6speedonline.com is recommending 36/44. Does anyone have any advice/experience with this setup?

earlyapex

I am assuming that the only change that you made to the car was change the wheels?

DrPeter

Yes, you are right, only the wheel change from the factory 5-spokes 8"x10"s

smshirk

IMO 44 cold pressure is too high. When the tires heat up the pressure goes up and my car appears to wander a bit. I went to 34 and 38 cold.

LVDell

Agree as well. I start at 34-36 front//38 rear cold pressures for daily driving. Now the track is a whole 'nother ball of wax.

earlyapex

Your car has been designed to understeer and the 18x11 rear wheels have only made this worse. The PSI recommendations that you quoted from 6speedonline are very high and will loosen your dental fillings. I wound run 36 psi in the rear and adjust the front tire pressures to minimize understeer. You will not be able to adjust out the understeer without going to adjustable sway bars and other GT3 suspension pieces to get you more negative camber. This is not worth the money and effort for a street car.

DrPeter

thank you guys, I will give it a try......

Paul Marangoni

If you're driving anywhere near Los Angeles, don't go too low with the rear tire pressure. You will bend your rims like they're made of tin on these roads. I run 42 in the rears with no problems. On the track, it depends on ambient temperature as well as track layout etc., but it's generally a LOT lower than that.

Carrera Mike

I'm running mine 2 psi less than the recommended presure. 34front, 42 rear for street use.

Eli K

The pressure you run will also depend on the tires. I've just recently changed over to the Dunlop R compound tires, and noticed that they heat up much faster than Pilot Cups. Now I run 32/30 cold...putting more air into the front tires...