Since this car is going to be a dual purpose car (street and track) we wanted a set of track wheels and tires. It also gave us the opportunity to move away from silver wheels and get some stealth black satin wheels. As we have done with other track builds we went with Apex Racing wheels. Apex recently came out with their RS line (a lighter version of their popular forged sprint line of wheels). So we went with the SM-10RS, in satin black. Not only are these light and look great, but it gives us the opportunity to down size from 20” wheels to 19” wheels. The OEM wheels are 20x9 in the front and 20x11 in the rear. By going with a 19x9 in the front and 19x10.5 in the rear we can increase the sidewall, go with less weight, clear the brakes, and stick some more rubber under the GT4 for added grip.
There are a few tire options depending on how much rubber you are trying to stuff under the GT4, but we ended up going from 245/35-20 in the front and 295/30-20 in the rear to an impressive 265/35-19 in the front and 305/30-19 in the rear. That is a material width increase in both the front and rear while keeping about the same stagger ratio. This size also comes in one of our favorite tires the r-compound Michelin Pilot Sport Cup 2 (180 TW). And to top off the package we will put in Porsche spec TPMS in the new wheels as well as an Apex stud kit for easy on and off applications.
No trimming or rolling will be needed for this setup, but we do need to upgrade the camber plates to allow us to dial in more negative camber. So for that we went with Targett front monoball racing camber plate designed for the 981/991/718. This should allow us to dial in -2.5 degrees which Apex recommends for this tire/wheel package.
Given the GT4 has a race car ethos, the OEM suspension is quite good. So we hope we can simply play around with the camber plates, alignment, and the wheel/tire package to get all the grip we need. Otherwise it’s going to get expensive quick and that is not the goal with this car. We will report back once we hit the track with this new setup later this summer.