BMW 330i E90 stock air filter vs K&N drop in
*No charcoal delete mod was done*
2006 E90
Automatic
Stock everything
Here is my version of the stock vs K&N air filter in regards to "sound" as many comparisons out there did not hold a proper control test to modified test.
Sound was taken at 16" away from exhaust at ground level.
The video will show what is being played and RPM goals.
K&N Install:
Install was simple and instructions can be found online.
Remove air filter box screws, loosen the clamp near the MAF, loosen attachment to the front scoop, lift out box and unscrew to remove the two halves.
Tip: If you do a charcoal delete, you will want to slip some newspaper between the K&N filter to absorb any excess oil from the manufacturer and then discard it before using.
If you don't do a charcoal delete mod, I don't find that you will have to do this as the charcoal filter will prevent excess oil from slipping to the MAF and causing problems.
Overall review:
I purchased the K&N as I have done so previously for my BMW that I have had for 10 years. I clean out the air filter during every oil chance (twice a year) so I see this as a good investment long term. Some claim that these filters will clog easily, but when you keep them cleaned they'll preform well.
Not much difference in terms of power to the car, nor sound except when letting off the gas there tends to be a deeper rasp from the exhaust. I do not know how so as I don't think the air filter would have an effect on the rasp when letting off the gas.
At $80 for K&N drop in vs $40 for an OEM, it was one of the first things on my list to purchase.
*and if you're worried about long term health of the engine from excessive particle intake. Most likely I will not be the owner of this car 10 years from now. Just as this situation came up with my previous 10 year old E36 which I no longer own. Not an issue for me.
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