Hi Mattk
why you don't used a tuned pipe on your OS33gt. the tuned with a good tuning provides about an increase of 500 to 600 rpm but it is not the case with the canister .
for exemple I'm runing tests on the RCGF 32 and the using of a tuned pipe on the APC 20x10,5 and the 19x11 allowed me to obtain theses results :
regards
steph