I like the sound, fitment, quality and almost-stock looks of the RB turboback, but I'm trying to make 400-500hp. Would it flow well enough, or should I just get a custom 4" exhaust for twice the price of a used RB turboback?

 

ooooooorrr... another thought would be to get the RB turbo back and plumb your wastegate a little farther back than usual (say beginning of mid-pipe or so), and put a cutout before the WG plumbs in, then you have a straight 3 inch pipe from the turbo and while it may be loud with the dump open, it would be pretty quiet when ity is closed and look stock...

thats Just a thought though... do what you want

oh and to answer your question, to the best of my knowledge the RB exhaust restriction is mainly in the mufflers (the sweet part of the system) and they are about maxed at maybe 350... That may not hold true to everyone whos used the system but I have seen one car with that kinda HP.

- Chris

 

I'm gonna be shooting for the 4-500HP range with an RB REVII turbo catback, presilencer, and A-spec downpipe with my A-spec 500R setup. I'll probably see if the RB becomes too restrictive and may end up switching to an Apexi dual N1 setup. I'll have some dyno results with each as well. I'll have some results in a few weeks.