Originally Posted by froop
I see you just went ahead and did it Jam.
Love the sound man. I think that I'm definitely going to have to go ahead and do this myself. I have gutted N54 mids as opposed to N55 mids but I like the sound of them at the moment.
I wonder if it's possible to get the BMWP exhaust and somehow modify it to make a quad exhaust...
Yeah, I kind of just thought that if I didn't like it, it would be easy to just bolt on the resonator in place of the Y-Pipe. Right now it's hella loud, cold start makes my brain vibrate and at around 2-2.5k RPM when pushing on it and opening up the throttle wide from lower in the rev-range (say 1500RPM) to get up some speed you get some cabin resonance. Cruising around town sounds no different really, part throttle sounds deep kind of like the ZHP E46 330Ci but a little louder, warm idle is deeper but not louder. Full throttle is where it's at, it screams a high pitched tone, sounds very high performing rather than ricey.
I cannot imagine this setup with catless DP's, I'd probably go as far as saying "don't do it" but instead get some Berk or Maddad style mids to tame it down, I don't even think the N55 resonator would be man enough. What I've found is that I get a little rasp sound when initially starting up, this is not vibration but what I believe is a characteristic of totally new, polished and coated pipe being bedded in...you know how new exhausts sound, a little tinny and less deep. The rasp is present only then and goes away when warm idling, partially remains on cold idling but is not present when driving or punching on it either. I imagine that with a fully catless car this rasp couldn't be muted and would probably extend to accelerating as well. If I ever go catless I'll be selling on the N55 mids (rewelded) and going for resonated mid-pipes. I guess you probably know this all anyway with gutted N54 mids, that must be loud also.
I'm giving it a few hundred miles for this pipe to soot up, it already sounds deeper after a good trip yesterday but it needs to come down a little more; not necessarily in volume but to lose a little of the raspy buzz you get on start up; then it's perfect.
As for converting a PE , I don't see why not. The Eisenmann quud uses a similar muffler right? I'm sure the muffler on the PE could be adapted the same.