Yesterday I was a little bored. I have recently installed a Conforti CAI on my M3. I love the way the CAI sounds and breaths. I wanted to install a CAI on my 325i, but I have already spent $3k on my M3 this month.
I went looking around the forums for ideas for a no/low cost way to let my car breath. Hereís what I found and did:
There is an oval plastic tube on the inlet of the factory air box. This help baffle the sound of the engine. It also restricts are flow. Solution: Remove it.
There is a tube that guides air from the front grill to the inlet on the air box. Its design is restrictive. Solution: Remove it. This is great, but now you need more air. The eaiest way to do this is cut a flap in the top of the driverís side brake air duct. Position the flap so it diverts some of the cold air up into the intake area.
Water Intrusion Delete
Just behind the driverís side kidney grill, there is a flap to help prevent water from entering the factory snorkel. Now that the snorkel is gone, we donít need it. You can use a hand saw to cut it off. With it gone, youíll get a lot more cool air in the engine compartment.
Hereís a good write up: http://www.apexcone.com/JimPowellHomepage/...t/h20prot2.html
The results are astounding. The air box sounds almost as good as my CAI and I can definitely tell the engine is getting more air. After some spirited driving, I popped the hood and checked the surface temperature of the inlet side of the air box. The air box was cool to the touch while the rest of the engine compartment was hot as hell.
Just an additional note: I already had a K&N filter installed. If you donít have one, you should really pick one up. That would take this from a free mod to a $40 mod. Still, not to shabby.