I have been in the tuner world for a while, mostly building supras and such and these cut-out's have done a lot to most turbo cars I've been around. Also the sound of the cars with the cut-outs open is great.. I'm sure the sound of a V12 would be great too..

This is what I am talking about:

http://www.quicktimeperformance.com/QTEC/index.php

Dual set up on the 850i.. what do you guys think? Would there be not enough back pressure with these open on a M70? Would these actually decrease performance on a naturally aspirated car?

On a M70, It will be a waiste of money far as HP gains.

Jenva, you probably wouldn't get any more power unless you installed some custom step up headers along with the cutouts but it would sound like an airplane taking off at close to the red line. Please post a sound piece if you do it because we would love to hear it.

Well since I have one for 2.5' pipe sitting here, I might go out and pick up another one. I will post a video for sure if end up doing this. Would it be a smart idea to do this after the o2 sensors if i was going to do it.

Just hoping it won't sound raspy, I've heard cut-outs on older m3's and it was just raspy. Haha the car with the cutouts will sound like ww2 german airplane thats for sure.

V12 will sound raspy.

...very,very,very raspy. Can you say: "ricer sound"?

Yeah I don't want raspy, so this concludes this thread.. I will sell my cut-out to some honda kid hahaha.