[Bmw doubles]

Originally Posted by lsturbointeg

Going 3" all the way back...how much of an improvement is that gonna be bro?

I'm no Supra, but check the results on this article

http://www.superstreetonline.com/how...ust-test-tech/

There's also a general explanation on this site that goes over the math of back pressure and turbo exhaust configurations

http://www.tercelreference.com/terce...st_theory.html

In the article above I learned more about scavenging and how an x pipe is not actually needed on turbo cars. If the xpipe is used to tone down the sound then just go with J Pipes.

I'm gonna my to dyno right after I get bigger exhaust piping and I'll let ya know

I'm going 3.5" collector inlet to dual 3" outlets, resonator delete and keeping my J Pipes.