Originally Posted by Project ST
Christ, 3"?!
You must be pushing around 500BHP to need that kind of low backpressure.
Hope your turbo's oil seals are uprated to handle the pressure drop*
(*awaits flaming from people who actually know something about turbos... 
)
/al
Wont flame, but that is bollocks.
Even 3in is seriously restrictive at 500bhp.
IIRC its starts to get restrictive on a cossie at jus over 400.
In an ideal world on a turbo car you dont even want to see 1psi in the exhaust.