Agreed. You don't want to go crazy with pipe size on a gas engine or you lose the scavenging effect, screws up your low end torque in a very noticeable way. 3" is fine for a big block, no larger.
On my HD I'm running 3" into 3" single in/single out Delta Flow 40's, with turndowns right behind them. No cats.
Richard
Post was last edited on Dec 27, 2011 01:31. Edited 1
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