ideal x-pipe positioning for performance gain?

[TowX]

Originally Posted by JCL

Best hp gain is with it on the bench. No location in the exhaust is going to give you any measurable gain, but putting it in the wrong place will reduce power. Your exhaust is already optimized.

Exactly!

As I've said previously, I lost so much power replacing my center resonator with a Magnaflow x-pipe and straight pipes that I had to tow in a lower gear all the time. This is not a simple change, there's a lot of science involved. And all my research says that the length of pipe ahead of the x must be equal for the pulses to cross properly in the x. And at least on the 4.4 V8, the length of the left cylinders is longer than the right because of the positioning of the exhaust to clear the trans and transfer case.

I pulled out my x, replaced it with a simple H-pipe and the performance immediately was back to where it was stock and maybe slightly better.