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      10-25-2011, 11:48 PM   #17
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2008 BMW 328xi  [4.10]
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Originally Posted by branmace View Post
+1 ^_^
OP: All the response that you've gotten here is spot on. I just did this, K&N filter drop in, charcoal filter delete, this weekend and tested the air volume CFM (cubic feet per minute) through both media surfaces (OEM paper together w/charcoal filter and the K&N).

Here are my findings:

1. OEM Paper Filter - 324 CFM (K&N claims,for comparison, average disposable filter 319 CMF)
2. OEM Paper Filter w/charcoal filter - 309 CFM
3. K&N filter (panel p/n 33-2332) - 453 CFM (K&N claims on the box 441 CFM but with a slightly different filter)

I have to say, I feel pretty confidant about the results.
Tools used: 24" long x 3" diameter PVC pipe, a 3" diameter nipple, utility knife, AirFlo Digital Meter, the filters above, garden leaf blower/vacuum, and the good old American Made Duct Tape .

Summary of the results:

1. If you go with charcoal delete and OEM paper filter = 5% approx. air flow gain. You will get some HP and/or TQ, but may not feel the difference. The same goes with any throttle response. (I'm thinking < 1 HP/TQ)
2. If you go with K&N drop in and charcoal delete = 47% approx. air flow gain. You will get around, speaking conservatively, 2-3 HP/TQ and more responsive throttle (I feel it throughout the RPM range and when you want to step on it, it listens). If I have to compare the throttle response to the BMS PBX, I would say up to 20% snappier throttle response.
***The HP/TQ estimates are at the crank*** Use 15%-20% loss at the wheels.
3. I also used CRC Mass Air Flow cleaner to clean the sensor prior to starting the car and wiped off some of the excess oil from the K&N filter, too.

Hope this helps.

Oh, and I forgot...CYBA SCOOPS "BLK" on order
You provided a lot of numbers, but can you provide a source or let us know where you derived these "estimates" from?

Tricking yourself into believing that you're gaining performance from these mods is different than actually gaining performance from these mods.

You're also stating that all of the responses here are correct, but they're mixed reviews. Even ********* said:

Originally Posted by ********* View Post
The purpose of the carbon filter is to scrub the air that can leak back out after turning off the engine. Its an emissions thing. Has nothing to do with the performance of the car.