For your WRX, I would suggest if you are using 17" rims, what I do is take my wagon to 6500 rpms and instead of slip off my foot off the clutch what I do is I just dump it, it will make your car spin those wheels and obviously it will break some traction, that way I got my 1.8 in the 60 ft. I've seen people get better but because they drive like hell, I granny shift all my gears
still I got my wagon with Turbo XS stage 2 to a 13.1 @103 mph
Cheers and good luck