I have my cat converter gutted out and i was wondering if using a Bönez Main Cat Race Pipe ( http://www.rx7.com/store/rx7/saexhaust.html shown towards the end of this page) will have any positive effects (performance wise) or any effects at all in place of the gutted stock cat converter? Any one know? Thanks guys! I have a feeling it won't help anything just because my cat is gutted...but i could be wrong.

 

if you do not have emissions, then remove it completely...

 

A gutted cat is noisy and causes a lot of extra turbulence, reducing power. If you need emmisions, that's one choice.

 

But if you don't need emissions, then get rid of it entirely. A gutted cat will decrease power in comparison to say, having a straight pipe or even a presilencer due to the fact of the size change in piping. When the cats open up to a huge space, the air stop moving as fast and fills all that in, then gets clusterfucked trying to come out the other side creating back pressure. Granted it isn't much in the least; however, a pipe the same size as the rest of the piping, or *ahem* a presilencer would gain you more power (in the range of what I'd say to be 2 or 3 horsepower, if that.) This is just my guess, at least.

On that same note, unless you have emissions testing, a cat would slow down the exhaust that much more actually having something in it to absorb emissions. That is the main reason that performance cars don't use them.

 

i have that race pipe and have no complaints. i had it inspected at jiffy lube i think, the 1st time and they failed it cause i had no cat. put on race pipe and passed no prob. i noticed more pep with the pipe than without it. i live buy walzem and 35, maybe we could get together and i'll so you. nothin special about my car except its mine.