Re: What does Race spec Eisenmann sound like??
I read somewhere online before and IIRC, it's around 25% louder than the OEM exhaust on the Z4. The exhaust will not be super loud because the race spec i believe is made out of stainless steel. If you want loud, titanium is the way to go. Massive savings in the weight area as well.
The good thing about Eisenmann is that their exhaust have more of a deep growl and rumble rather than a high pitching screaming honda wail.
IMHO, i think you've made the right choice.
P.S. When will you get the exhaust? I'd very much like to hear it in person.
Cheers!