My precats and 3rd cat have to be replaced. I’m hoping to pick up some power without a lot of noise. I need a cat to pass inspection. I’m thinking of using racing beats Road Race header with a single high-flow aftermarket cat.

If I use the Road Race header (with the o2 backpressure sensor), does backpressure from the cat or piping matter? Can I follow the header with a mangaflow high-flow cat and 2.5 inch pipe to the mufflers? (Basically what the muffler shop wants to do with the RB header instead of their custom header so the backpressure will be correct.)

I’m also considering the “Racing Beat Street Header/Bönez Cat System” system from rx7.com. Any difference in performance between this system and the Road Race header/magnaflow cat system? Is there a cat-back system that just bolts on (so I can install myself)?

Are either of these options going to make too much noise?

Basically, the local muffler shops want to sell stock or sell whatever they carry. None of them seem to know anything about rotary backpressure. I can get almost anything done, but I'm going to have to design it.

 

a RB header will inscrease noise drasticly, however it all depends on what mufflers your using, if you use fart cans it willb e very loud,, however real mufflers actaully keep the tone down.

for noise id recomend the RB catback, its not going to bolt ot a "custom high flow cat setup" cut it can be made to by any muffler shop.. that way your more "legal" if you have a cat still and your cars not too loud.

 

Buy the entire Racing Beat System, it's matched for a good exhaust note / tone and less noise.

 

If you're worried about emissions check:

httP://www.rx7.com

And take a gander at the RB header/Bonez Highflo cat. Its tested and rpoven to withstand heat and the such.