hello, my integra type R is jrsc powered at 10.7psi with lht cooler

my exhaust is external 60mm,

i read the best for my setup is header 2,5inches and full axhaust 2,5 inches (almost 63mm)

can you tell me if it means 63mm internal or external?

thanks for your help

mike

 

exhausts are measured on an external diameter.

 

What other mods and what kind of power are you putting down? I'm on Non-LHT JRSC @8.5psi

 

my last dyno with only 9psi and lht made 268hp

 

Yay for another wrinkle in my brain.