im currently running a high flow cat but was thinking of running a test pipe instead, would there be a difference in the hp side(probably not), but will there be a change in sound, im running the megans racing drift spec catback, stock header. can anyone give me some info please, thanks

 

Small increase in power going to the TP. Exhaust probably won't be louder at WOT but the TP may cut back on any drone.

 

Most HFC's are somewhere between 80-90% of total flow, compared to test pipes. By small increase, you mean incrementally small; like shaving weight only by swapping to a optima battery and saying your faster, small.

To the OP: Sound will be more boomy. I'd leave the HFC on if I were you. I switched from a 3" HFC to a 3" TP for an experiment, and I hate how boomy it is now, and plan on buying a new HFC soon.

 

Not worth the time and effort, IMO. Spend your money on something else.