Right now my car has an RS*R ExMag 3" CB exhuast. The car was flashed and tuned today but the numbers were a little dissapointing. Mike at Gruppe-S thinks the poor numbers may in part be due to the stock cat prematurely failing. He suggested replacing it with an aftermarket high-flow cat. I figure if I do that I might as well replace the downpipe in the process. My question is which 3" high-flow cat will be a direct bolt on for the RS*R exhaust? I believe the exhaust has a slight taper where it meets the cat. Also, any 3" downpipe recommendations would be appreciated. I've read through most of the big downpipe threads but the scope of info is somewhat overwhelming. I would love to hear some other opinions.

 

i'm running a Ultimate Racing 3" HFC with my RSR Ex-Mag. The inside diameter of the mating parts is just slightly different, but work fine.

 

Thanks. Do you know which has the bigger diameter?

 

I dunno if it fits the Ex-mag but my buddy has the Invidia DP and it is a beautiful piece. I got one too, it's not installed yet though.

 

I've heard good things about Invidia. Whether or not it hooks up to my RSR exhaust isn't really important since I'll have a high flow cat between the two. Are you going to run this downpipe off your stock cat, and is the Invidia piece a 3" design?

 

Not installed yet, but it is a full 3" design. Like I said it's real pretty.It bolts up to my helix HFC so it's cool with me.

 

Are you gonna try to do the install yourself?