128i (N51) SULEV performance kits

[Taskmaster]

Originally Posted by bbybimr

I did find this airbox mod at http://www.1addicts.com/forums/showthread.php?t=719604

It says:
Short story is as follows:
- charcoal filter delete, no way back if you do this
- remove drop in filter
- smooth out ribs in intake box, if you are hard core
- buy home depot piping/ mounts
-cone filter of your choice, i think we need dry ones
- mount with home depot hardware, be careful around MAF
- cut hole in front side of airbox ala AFE stage 2, BMP, Euro box

if have euro box, can add a hole in the front. I seen it on babybmw forum
Posted by Andrey GTA

Anyone ever try this? More importantly, did it work?

I'm going to try this one out....

[bbybimr]

Originally Posted by TheAxiom

I'm going to try this one out....

Awesome....Your so lucky to be able to do this...lol. In California, we get spanked for this kind of mod by the smog police...(CARB).

However, I just received my K&N drop in filter. So I'll check it out and report back later.

[bbybimr]

Short story is as follows:
- charcoal filter delete, no way back if you do this
- remove drop in filter
- smooth out ribs in intake box, if you are hard core
- buy home depot piping/ mounts
-cone filter of your choice, i think we need dry ones
- mount with home depot hardware, be careful around MAF
- cut hole in front side of airbox ala AFE stage 2, BMP, Euro box

***

On this procedure, I do have a couple of questions though...

If you smooth out the ribs, won't that increase turbulence inside the box?

And where the h@ll do you make those holes in the air box? Without precise placement and dimensions you could ruin the performance and the box.
Anyone got pics of the procedure?
And what gains did you see?

[Taskmaster]

From my dyno, a Charcoal delete is worth 2/3whp over a Stock Box - these modifications would probably add up to 5whp at the most.