Exhaust piping size etc

[EURON8]

for maximum power gain get 3in exhaust

[EUR003act]

for maximum power gain get 3in exhaust

i think he's going by the no back pressure rule...

its not all about pipe size for back pressure tho, mufflers play a massive part in this! example, you put on a 3" exhaust, but need four mufflers (same as jtunes) to keep it quiet... where as hks uses 2.5inch pipes and only three mufflers... that one less muffler addding back pressure, so they prob both have the same flow capabilities...