I have a stock s4 Na with a racing beat header (just bought the car this way) and the previous owner made a "Custom" exhaust system complete with crappy piping horrible welding and 0 bending the worst system i have ever seen ended with the crappiest non fitting muffler he could find. now my question is i plan on keeping the racing beat header and buying an apexi N1 exhaust since my engine is bone stock i plan on just doing a single not the dual. there is no cat so i know i need a presilencer. what exactly would i need to make this system work? i have been looking around and have had not much luck so far. any help would be much appreciated.
thanks in advance

 

You already listed out what you need. A presilencer & a 2.5" catback system. It'll bolt right up, if the previous owner didn't modify the header length/flange.

 

is there any particular presilencer requirements that you would know of or branding

 

Yeah, the Racing Beat header is shorter than others, so that you can use their presilencer. The RB header combined w/ the RB presilencer will be exactly the same length as the original stock equipment (precats + main cat), so the it'll be in the correct spot for any catback system to bolt up.

Also, the RB presilencer has a pick up tube for the split air pipe. If your car doesn't have this pipe right now, it's likely your aux. ports are not working. Or the previous owner may have wired them permanently open . Aaroncake has some more info on testing them on his site here: http://www.aaroncake.net/RX-7/6porttest.htm. And here: http://www.aaroncake.net/RX-7/6portfix.htm

 

thanks a lot for your help