Its only been dyno tested on the v8 models so I cannot say if you will see the same results.

 

Umnitza sells a quad setup for a 530i that they claim has proven gains:

https://5series.net/forums/topic/872...haust-for-e60/

 

Claim? Im pretty sure is was proved. Or wasnt it?

 

It would be awesome to see a race between the 'dyno proven' quad exhaust and a competitor's single sided setup, such as RPi. i'm willing to be the single sided will win every time.

 

Possibly so, but the look of the quads is just so much more bad ass. So you really have to consider what you wanna do if you want looks, or if you want to be fast and furious. Is up to you.

 

I think it would be extremely close in performance if you test against the setup West and I are using. I would have to agree that it would be awesome to have a dyno show down.....quad vs single

UPDATE: Talked to an exhaust shop today and I'm going to cruise by on Saturday morning to have him take a look and see what he thinks. This guy has done a ton of various applications for a wide variety of cars including M5s. He can do custom headers, x-pipe, full exhausts, etc. Work looks really good, better than some of the aftermarket brands I've see here so I'm really excited to see what he thinks. The anticipation is killing me right now...

 

There were no dyno results posted by anyone else besides Umnitza, hence why I said "they claim".

 

Check Member WEST he did a pre and post Quad setup with part numbers and pricing and showed
a 10.5 hp gain on a DYNO!!!
Will be doing this setup in the Spring
after my M5 rear gets painted...

 

^^^ West's setup is posted in this thread.

 

I just printed these pics, im take it to my local muffler shop to see how is the install. Before I order anything.