Ya, I know back pressure is important, that's
why I haven't done it yet, but on a Turbo motor
back pressure is not needed, the turbo force feeds
the motor, and creates the back pressure needed
to build torque in the lower RPM range, after the
turbo, the less pressure the better, so 3" here we go.
I was talking to a guy at Car Craft in Riverside, 2000
+ cc VW engines turbocharged putting out 200+ HP
and 3" pipes right out of the turbo, I asked why and
he enlightend me to the HP that could be had by opening
up the exhaust system.

Wild