Quote:
Originally Posted by tdott
It would be great to compile results of various types of xpipes.
My headers with catless xpipe made +15whp / +8wtq over test pipes.
http://www.tdott.me/2019/06/project-...mw-e92-m3.html
Did anyone notice how Valvetronic's catless x-pipe makes less power over a fully stock xpipe, than test pipes alone make?
Spencer's video only shows +12whp & +9wtq over stock, and it's fully catless. 
Test pipes usually make over 20whp over stock. I don't have any dynos right now but there were many in the past, just have to search for them. |
He did say that he didn't change to a catless tune, which probably explains the smaller horsepower delta.