Just out of curiousity, but why 235 series tires on a car with about 100 whp? It's not like there's a lot of power you need to get to the ground.
My old speed3 had about 270whp with 225 series tires and i had to try really hard to get those wheels spinning. I can't imagine 235 series tires on my P5. All you're really doing is adding a whole lot of weight to each corner.
thats cool i got 205/50 on my stock rims and they ride nice.