I just bought a gutted cat, i thought it was a test pipe with the heat shield welded onto it, but it seems it is just a stock cat with all of the internals taken out. With that extra space is that goin to help or hurt my power? I have the stock exhaust on there now, i do have a header but i am goin to get an aftermarket exhaust soon, what will happen to my power then?

Thanks,
Matt

any help would be heavily appreciated

 

The stock cat sucks maybe 1-2 horspower, and you won't see much gain running a gutted one. Newer cat designs are pretty effiecent, unlike the garbage from the mid 70's that got cat's their bad reputation.

 

i bought an aftermarket one and it was totally gutted but where the guts where are now empty, so then i may lose all brake pressure and in essence lose horsepower. So that was what i was really worried about.

Thanks,

Matt

 

it wont hurt you, but it wont help much, if at all.

 

what if i shoved a pipe inside the gutted cat and turned it into a straighht pipe? would it just have the same efeect or make it better?

Thanks,
Matt

 

all that will do is choke it down more. just leave it until you can get a real hi-flow, or a test pipe.

 

wouldnt shoving the pipe in there make it a straght pipe though? If there is a difference besides a single pipe and then a pipe with a bubble in it and a pipe shoved through the bubble then tell me, otherwise i am confused of the difference.

Thanks for your help,
Matt

 

a gutted cat and a test pipe will be about the same performance wise, the gutted cat's gonna have a nasty echo chamber sound to it though

 

the inlet and outlet of the stock cat are already tiny. shoving a pipe into that space will only make it smaller.

 

the guy that i bought it off of said it was an aftermarket one from catco, but the inlet does not look much bigger, nor the outlet. But all the internals are gone, so i thought maybe a pipe would help make it the straight pipe i thought it was in the beginning

Thanks,
Matt

 

If you're that worried about it, just cut the flanges off of the gutted cat and weld them to the front/back of an appropriate diameter tube.

 

haha, thats what i did before i built the 3", but i used some 2 1/2" pipe from the hardware store. helped me spool a little faster, but i think it would be a waste of time on a mildly modded car