Hoosier question. Go square with 295/30-19 R7's or 315/30-19 rears?

[Mad Hatter]

My buddies GT is due for new tires, he currently is running with Stiffer BMR front bar, no rear bar, Stoptech st60 15" brakes, Cortex Race setup with Koni's, . Would going to a pair of Forgestar F14 19x11 with 315/30-19 in the rear be worth it. Or just stay with 295/30-19's on 19x9.5 SVE wheels. The car has about 450rwhp. He has a heavy foot!

 

[Grant 302]

Unless the car currently oversteers, it might make it harder to drive if the tire change makes it push.

 

[VoodooBoss]

He'd be better off with wider wheels regardless of which of those two tires he uses. Those 295's are spec'd for 10"-12" wide wheels. So 11" would work for both or even wider for the 315's. He's not getting the full contact of the 295's on 9.5" wide wheels. Both CorteX and Vorschlag like running as wide as tire as possible on our cars so contact them for specific fitment advice.

 

[Mad Hatter]

We okeyed the 19x9.5 with 295/30-19 tire with Hoosier before hand, Since the tread width is 10.4" it was just within the one inch rule. It was a very cheap option! But going to a wider wheel I am sure would help. Trying to get the offsets for the 19x11 wheels. I guess front and rear would have to be different?? Thinking something like +33 fronts and +56mm offset rears? Probably Forgestars F14. The big 15" stoptechs are the only reason for the 19 in wheels.

Once the rear stock gt bar was off the oversteer improved, the front bar is on full stiff but we softened up the front shocks a little to decrease the understeer. So far the improvement has been great with times down to 2 sec (with R6s with 50 plus heat cycles!) behind a 800Hp GTR on new Hoosiers

 

[DGRacing]

Whether to go square or staggered in tire size is a complex process. Square is very popular and cost effective and can work great with the correct other parts. Corner balancing the car is essential to get the most out of square. I ran square for a long time but recently put more rubber in back. The reason was a solution to a condition which was slight loose on corner exit where I need to put the power down. To compensate the effects of this on corner entry I had to change my driving style and in some cases line. Fortunately the answer there was MORE corner entry speed. So tire setup is part of the complete performance picture and should only be changed to address a handling concern in my opinion. But square is the place to start that process.