TD's under the axle
 

My car is a daily driver and I need to put cats on it due to the exterior sound level. I'm also going to run my duals out the back under the axle. This may be a dumb question but when I have the pipes built to go under the axle would it be possible to put two hi-flow cats in those pipes?

I want to do this because then if I went to the track I could just unbolt those two pipes and run w/ no cats. Thanks ahead for the help guys

Tyler

No it won't work as good. in order for cats to do their job they have to get VERY hot. and way back there they won't get as hot as fast. and IMO under the axle duals look like ass.

Cats would be near worthless that far back, they need to be right off the header.

Your in Texas...You shouldnt have to worry as much as the CA guys. no cats will only give you 5hp max anyway.

Yep you need the cats straight off the headers.

Also a good cat won't affect exhaust flow much or maybe at all, they may affect the exhaust pressure wave but on a street engine I don't think it's much to worry about.

Random Tech offer some nice CATS their 7000 series metal matrix ones outflow many mufflers and are good for ~550bhp if you run one per cylinder bank.

Magnaflow carsound CATS are also very good and probably will pose only a minor restriction (of that) on your setup.