Originally Posted by j-fire
the point i'm trying to make, is perhaps we are trying to use too much 'larger' pipe, and maybe for a 'true dual exhaust' we should use 2" or 2.25" on both sides, instead of 3" on both sides! 3" of exhaust pipe on only 3 cylinder heads each side seems excessive, and maybe is not 'balancing' the power curve.
A large, cat-back exhaust on our cars probably isn't going to do much - the exhaust manifolds into stock cats will be the major restriction. Deal with that properly, and you'll probably notice more meaningful gains.