Why does the 1M sound raspier than a 135i???

[CrimsonXV]

I've watched many exhaust videos of N54 135i, N55 135i, and 1M. No matter what exhaust system each car has fitted (catted, c@tless, even stock) the 1M has a raspier sound (similar but not as harsh as the e46 M3). The only thing I can boil this down to being attributed to is:

1. The fact that the resonator in the 1M is fake and is actually a through 'Y' pipe, or
2. The N54B30TO is in fact tuned differently enough to create the raspiness (with no actual physical change in engine components from the standard N54, AFAIK. Correct?)

I want/hope to make my N55 135i have this raspier more aggressive sound. I love it, particularly like this 1M with akrapovic exhaust.

Does anyone know the answer to this question/challenge?

[Marc08EX]

To answer your #1 question, check this post out:

http://www.1addicts.com/forums/showp...1&postcount=15

[CarJunkie]

The 1M resonator is in fact fake, but that wouldn't make any difference on aftermarket systems that replace it. Another possible difference is the turbos. I am not sure whether the small twins flow differently enough from the twin-scroll single turbo to make a difference.

[IEDEI]

funny because i think my 135is (N55) was raspier than my 1M.

go get yourself a BMW Performance Exhaust and a PPK2 kit......that package sounds wicked.

i do like the overall 1M sound more because it has more bass to it...but i think in terms of screaming the 135is did it better.

I'm still waiting to get my Vorsteiner exhaust installed...haven't had the time yet. It's just collecting dust.

[CrimsonXV]

Ya I'm am aware that the resonator is fake in the 1M, I was actually stating that as a reason not asking if it was fake. I was actually trying to ask if the fact that it is fake and is a 'Y' pipe is what makes the 1M sound raspier (I.e. If I remove my resonator will it make my car raspy like the 1M)

Car junkie, to your point, an N54 135i should sound the same as a 1M because it has the same turbos (bar the resonator), correct?

[EldRick]

That snarl comes along with loud peaky resonances in the 2k-3k RPM range.

[MDORPHN]

1M also has different downpipes, with less dense cats.

Neil

[CrimsonXV]

Originally Posted by MDORPHN

1M also has different downpipes, with less dense cats.

Neil

But I have listened to many videos of 135i running catless downpipes and they still do not have rasp like the 1M.

I wonder if anybody has tried any different universal mufflers and gotten a different sound than the exhaust systems which are commonly installed/found from supporting vendors. Anyone?