I don't know if anyone else has this combination (I couldn't find it when I looked), but here it is for those interested. I already had the Eisenmann sport so I'm just adding the Akra mid section.
I received my Akrapovic mid section - consisting of downpipes, 100 cell hfc's and the xpipe last week. I couldn't get around to install it until Saturday. I figured it would only take 45 minutes or so to bolt the sections on to my existing Eisenmann sport.
"It's so easy a caveman can do it." ... right.
First off, as many have said, the exhaust is really a work of art. Words cannot describe the quality. I got it from the always awesome Ilia @ IND and received it very fast. I used my ipod to take a pic through the 100 cell hfc's so you could see how free-flowing they are. I held it up to the sunlight, and although it is part of the x pipe with the resonators on the opposite end, you can directly see the light pass right through the honeycomb. It was actually much easier to see through than the pic portrays. Needless to say, you can't see squat through the stock cat.
So back to the ease of install... not soo much. The stock sections dropped off in a flash, and the downpipes were equally fast to install. The xpipe, however, has a special adapter connection at the rear designed to mate with the stock (or in this case Eisenmann) connecting pipes. Probably to ensure quality connections, the adapter has a few inches of male pipe which sleeves into the stock connecting pipes. The few inches of that sleeve prevent you from installing the x-pipe section without also dropping the rear/muffler section. This is probably not usually a problem since most people are buying the full exhaust and will install the rear mufflers last instead of trying to squeeze this midsection between an immobile front and rear section. So what started as a 45 minute bolt-on plan turned out to be about 2 hours. Still, not bad all things considered.
RESULTS:
First let me say that I am an audiophile and have very sensitive ears. Whereas many may not note any drone from the Eisenmann sport, I do. It is transient, occurs at very low rpms, and thus, is not consequential. In the new setup, I notice more drone in a few low rpm regions you wouldn't be driving around town in. Still, it's there, and there's more than before. My opinion is that it's still very transient, mild, and inconsequential.
I approximate overall external volume at idle to have increased about 15-20% over the sport alone- still mild. Tone is about the same at idle. Inside the car, there is no noticeable difference post-op... neither is there a difference driving windows-up below 5K or so, thereafter internal volume is slightly higher but very civilized. Radio, bluetooth, etc are still fine.
Externally, the pig's tail gets yanked somewhere around 6K. It was raining this weekend so I couldn't do audio for you, but I will try on thursday. It's better that I let you hear it than describe it. It's definitely more aggressive.
I love it.
Comparatively, the tone is definitely different than the full Akra system, and I think it is slightly less loud than the Fabspeed-Eisenmann sport combo-which I also really like. The Akra system is a perfect fit and there's no worries over any part of the system hanging low and scraping since the cats are moved to a flush-fitting posterior location. It is also, obviously, very light.
It took 3 days/ about 60 miles for the "increased emissions" light to come on. Funny part at the end of the revving vid is when my 2 1/2 yr old says he didn't like that noise it was too loud.