Imaginary STF build

[ilikerice]

The rear have camber shims that are pretty much what your asking for as far as swapping on the fly, but that is just the rear.

You are asking to have your cake and eat it too. I run -2.5 in the front like I said. This is a very good setup for DD and track driving for me. If you are going to be wearing your street tires out using this camber, then the only other option is to have your tires flipped every 5k miles to get the most out of them. When I say flipped, I mean taking your tire to the shop and having the same tire on the same rim flipped so the outer is now the inner and inner is now the outer. A lot of autocrossers so this also. I have been fortunate to not have this problem.

Again, my track tires are 225/45 on a 15x7 with offset of -40 and my DD are 205/50 on a 15x7.5 with offset of -30

Track tires with RS3 I run 40psi up front and 55psi in the rear
If I run R1R, I run 30psi up front and 45psi in the rear.

my DD I run 40psi all around

[CoryM]

Originally Posted by ilikerice

Track tires with RS3 I run 40psi up front and 55psi in the rear
If I run R1R, I run 30psi up front and 45psi in the rear.

Just curious, how did you end up at those pressures? Maximize front grip, then tune rear to suit driving style?
My car runs about 10psi more up front than rear in HS and HS-R. Obviously I need more front pressure to keep the edges alive with stock springs, but the car savagely understeers if the rear pressures are any less than 10psi lower than front.

Also, how bad is the extra weight of the 225s and do you get enough heat in them every run?

Thanks.
Cory

[ilikerice]

Originally Posted by CoryM

Just curious, how did you end up at those pressures? Maximize front grip, then tune rear to suit driving style?
My car runs about 10psi more up front than rear in HS and HS-R. Obviously I need more front pressure to keep the edges alive with stock springs, but the car savagely understeers if the rear pressures are any less than 10psi lower than front.

Also, how bad is the extra weight of the 225s and do you get enough heat in them every run?

Thanks.
Cory

Well, the 225 are only 1 extra pound per tire compared to the 195.
http://www.tirerack.com/tires/tires....del=Proxes+R1R

I will sacrifice some acceleration for the extra grip. As far as keeping heat. I don't have that much of a problem. They are not R-comps, so they don't need to be above 200 degrees in order to be sticky. RS3 are fine after the 1st run. They hold 150 up until my next run. Granted, there is no way of me knowing how hot they get while I am running. After I park in grid, I will check the temps and my fronts are usually 200ish across the tire and my rear are 180ish outer and usually 10 degrees less on the inner. Probably due to the high tire pressure. I am sure if I got .5 shims in the back that I could get the heat the same across the rear tires, but I dont want any more grip in the rear that I have already.

I get my tire pressures from experience and my driving style. I like my rear to swing out when I come up to a turn or during a turn when I lift off the throttle. I would rather lift off the throttle than left foot brake to maintain my momentum during any kind of turn.

With that said, The R1R like little bit of pressure unlike the RS3. R1R if more than 35psi, I get more under-steer than I like. Even with 30 psi up front, I am still wearing out the tires evenly. The shoulders on the R1R are very tough and dont flex as much as the RS3 either.

The RS3 like more pressure up front because they have a softer side wall and will roll on it if the pressure is not enough. A lot of heavier cars wont run RS3 in Street Touring class because of this. They will run Direzza Star Specs because of the side wall issue.

Hope this clears up my reasoning behind my choice in tire pressures. Again, its all about driver style, trial and error.