For a stock turbo application... which diameter is better (3" or 4")? I hear that http://www.turboxs.com/ is coming out with a 4" diameter DP. Will this make any difference?

4-BNGR

 

3" is more than enough for the stock turbo and good till around 500 hp.

 

There are 800whp 4cyls with 3" downpipes. 4" is a waste and would probably never fit on an EVO VIII anyway.

 

Highly doubt it would clear front suspension. Actually i pretty much know it won't. My 3" comes close.

Jeff

 

I would think that unless your turbo was port matched to that downpipe it would do more harm than good. You would create a lot of turbulance right after the turbo which would increase back pressure which would increase spool up time.... So basically I don't think it would be very beneficial