I've read in a couple of places that there's a way to cut open and mod the S4 uim to increase top end power, but I can't find any details on it. Can anyone explain how it's done? Is it just a matter of cutting it open, gutting it, and then welding it back up?

This is for a lemons car and any free mods that don't hurt reliability are good. This is a track only car, and I don't really care about hurting power some below 4k. It has full exhaust and a large streetport.

 

Extrude hone? That's the only modification I've heard of.

 

http://www.rotaryresurrection.com/2n...s_removal.html

 

^Why link to emissions removal?

 

nevr heard anything along those lines...

only one i know makes a little difference is the Fd uim

 

That is for a turbo car. I think someone experimented on this a while back, a few years ago. But the gains wouldn't be worth the work, I don't think.