Originally Posted by Mike Rainbird
I think the exhaust needs looking at as well! Measure the back pressure, I bet it's the same as the boost pressure
.
But backpressure can be 3times boost pressure and still be making good power.
Its not an ideal situation, but be suprised if a 2.5in is holding him back THAT much.
How far away from 400bhp are you now? Still at 336bhp yeah?
Ok, maybe it is the exhaust, didnt realise youd got that high already.