my exhaust set up

**FastAssZ** · 09-16-2005, 01:08 PM

alright guys i need your oppinions..... im gonna be putting my headers on this week and im not sure what i want to do for the Y pipe. i was thinking of running cats and cut out's, but should i put the cats first then the cut out's or the cut out's then the cats? i was also thinking of those set ups where you have the cats and can pull then out and put straight pipes in but instead of straight pipes just use the cut out. Is it bad at all to have the cut out's straight after the header, would that hurt the engine at all? im more leaning towards just the cats then cut out's but im not sure. let me kno what you guys think and what u have done and which u like best. thanks guys!

BlackHawk T/A · 09-16-2005, 01:10 PM

The cats need to go right after the header. I really do not recommend running a cutout right off the header, basically having no pipes at all. You won't like it, and neither will the neighbors or the police!

Rhino21149 · 09-16-2005, 01:46 PM

If you put the cutouts before the cats then:
1) you have essentially straight pipes for the track --they will make a lot more noise when open-you will not be able to use them on the street. But you might get a bit more power. I have a SC 427 in my vette and even with the biggest cats available, I lose close to 30 HP (I don't have cutouts, I just remove the H pipe at the track).
2) Of more concern maybe, the cutouts upstream, the cats will be further back from the engine, which means when you are on the street, they will run cooler, which is not good, just a few inches farther back will cool them off some: thus, when the cutouts are closed and you are on the street, the cats won't run as hot and thus won't work as well at reducing emissions. If your state actually tests for emissions (where I live they just query the OBD and if it says all is okay, then you pass), then you might have a problem.

**FastAssZ** · 09-16-2005, 02:36 PM

so basicly it has to be cats 1st then cutouts. which would you guys recomend, the cats then cutouts, or no cats n just cutouts?

bottlefed · 09-17-2005, 04:59 AM

can u run no cats in cali?

**Hurley711** · 09-17-2005, 07:34 AM

Yeah bro you are in CALI, are headers other then shortys even legal there? You better check what u are doing first unless you have a "Friend" who is going to help you pass emissions