okay now i know the topic of exhaust piping size has been

but i have sort of a different question.

now i believe stock and most aftermarket headers have a collector of 2.5"

i believe most test pipes fall into this range as well (i have berk technologies)

now i know that 70mm (2.75in) makes more power than a 2.5in.

however i also learned that the consistantcy (sp?) of exhaust gasses is also important.

so my question is.

would i make more/better power running:

2.5header -> 2.5 test pipe -> 2.5 exhaust

or

2.5 header -> 2.5 test pipe -> 2.75 exhaust

 

well, i think the 2.5 colector with 70mm tp and 70mm exhaust(single)+nice ecu upgrade will be the best n/a.

but imo between the 2 choices :2.5 collector with 2.5mm tp with 70mm exhaust will make slightly more power.

i am currently running a toda header,t1r TP 70mm and t1r 70mm exhaust plus hondata reflash...

i think the only way to really find out on which mods ur cars gonna make more power is to dyno it with some ecu tuning, coz each car is different.
if u r going to do a custom exhaust..make sure u have it made as straight shot as possible(the lesser bends the better) because the more bends u have will create some sort of affect on the "free flow theory".

good luck...

 

If you are going for max power the 70mm test pipe will probaly be your best bet. Some form of ECU tuning is necessary to get the power out of those mods though. Without it you really wont get much power in comparison out of it at all.