986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - Pre-cat bypass vs. secondary cat bypass

jmatta · 08-07-2010, 05:32 AM

I have replaced the secondary cats with Fabspeed bypass pipes and installed a modified "PSE" type OEM muffler on my '02 S. This not only gives me the sound I was searching for, but feels stronger to me, as well; though I do not have dyno data to back this up. I really question how much, if any, there is to gain removing the factory manifolds/pre-cats and replacing them with headers on a street car?

Seems like more trouble than it's worth for a few HP (at most).

Edit* After reading the post again, if Jake recommends replacing the manifolds, there certainly must be merit, but I think I'll pass...not worth the hassle.

08-07-2010, 05:32 AM	#12
jmatta Registered User Join Date: Nov 2007 Location: Chicago suburbs Posts: 1,675	I have replaced the secondary cats with Fabspeed bypass pipes and installed a modified "PSE" type OEM muffler on my '02 S. This not only gives me the sound I was searching for, but feels stronger to me, as well; though I do not have dyno data to back this up. I really question how much, if any, there is to gain removing the factory manifolds/pre-cats and replacing them with headers on a street car? Seems like more trouble than it's worth for a few HP (at most). Edit After reading the post again, if Jake recommends replacing the manifolds, there certainly must be merit, but I think I'll pass...not worth the hassle.* __________________ JGM 2002 Boxster S 1973 911 Green FrankenMeanie PCA DE Instructor circa '95 Last edited by jmatta; 08-07-2010 at 05:37 AM.