So I know a guy who bought an RB header for his S4 and an Apexi N1 single exit catback. He needs a cat for 6pi operation and I was wondering if there is a bolton cat available for this application? Now I ASSUME that the Apexi atback bolts up to the stock cats so would this mean that the bonez cat (made for use with the RB header) would fill the gap between the header and the exhaust?

Here is the link on the cat:
http://www.rx7.com/store/rx7/fcexhaust.html scroll to "Bönez Catalytic Converter only - for use with Racing Beat Street Header"

 

There are 2 different RB headers, one is longer than the other and goes into one pipe, the other has 2 seperate pipes, usually used for a true dual exhaust. I currently have the rb header and cat that came from rx7.com with my corksport catback, basically the same thing as the n1 but I don't have the second muffler between the cat and the final muffler. I passed emissions no problem with that bonez cat on, but I didn't pass the noise test. 104 dba at 2500 rpm and 95 dba idling.

But yes, that should work if he has the same rb header as pictured in rx7.com's picture. That is what I have....


EDIT: I just realized you said it's an S4, so I'm not sure, mine is an S5. But it does have that little thing that sticks out the side for the air pump...

 

i used to run rb header with N1 catback, and it was completely and rediculously loud. It seriously hurt my ears... the droning was horrible. Now my car is ported and has no exhaust diffuser in the engine, but I still think you should think twice before you put an N1 on there with the RB header. I switched to RB catback and it sounds better and doesn't give me a headache

 

If you dont have emmissions, you can get the presilencer from racing beat. It has the thing for the split air tube as well. Also, I would make sure that the cat has the thing for the split air tube, as some don't.

 

Now that I think about it, my kit did come with a block off plate to remove the air pump (i think) on S4's.

 

i would do the presilencer from RB. i have that with a RB header and N1 catback and everyone including me likes it

 

keep in mind that if they do find out your not using a cat, you will get a VERY nice fine!

 

in some states. most will just fail you and make you get one.

Now any exhaust shop that is caught making an exhaust without a cat for a street car is subject to a $10,000 fine.


BC

 

I'm saying like if a cop sees flames shooting out of your exhaust and he pulls you over and checks for a cat. I don't think deq would care, just fail you.