I'm guessing you're running on carpet....
Nitro Foams are the only foams where you will run a 26mm wide front and 30mm wide rear.
I run TRC and they are 28mm wide. Usually Cyan Front and Magenta Rear on my LHS's track. ( Dbl Pink and Dbl Pink/Orange with Jaco's)
You need to see from other racers what compound works where you are running.
I still lurk....