[MA78]

Has anyone swapped out their factory air filter for a K&N yet? When I had my intake replace on my last car with THIS, I thought it made a pretty good difference. Due in no small part to the better filter I'm sure.

[Razel]

Not criticising, just that a "butt" dyno isn't going to be too accurate, and can be influenced by the brain to some degree.

About 10 years ago, with folks thinking the K&N Filter made a difference on a BMW K75 motorcycles performance, some die-hard guys got it on a dyno and check it out. No difference. They followed that up with some saran wrap covering half the OEM filter. Still no difference.

Finding an all-wheel drive dyno might be a bit of a challenge, though.

[tuco44]

I have, in the past, used K&N oil filters on some vehicles (usually Detroit iron, not as "technical" as a BMW engine). I'm not sure it made much difference. I think some ppl who use K&N filters forget to do the regular cleaning procedures that these filters require. I would not be putting it into any BMW I wanted to keep for a long period, and I would be careful with BMW warranties if you do use it.

Just my opinion.

[bekind]

Add me to the group that thinks these don't make much difference. Based on the information I have seen a quality OEM paper filter will flow just as good if not better assuming you replace the cheap OEM filter on a regular basis. Plus when you go to clean the K&N filter you have to be very careful not to over oil. I have seen numerous cases of the MAFs becoming dirty due to too much oil.

Even in the past when I have added an entire cold air intake (CAI) I have stuck with an OEM filter.

I would be very surprised if you saw improvements, if any, with just putting in an over priced oiled filter. I haven't dove into modding the N55 yet but your best bet for performance gains would be with an aftermarket tune.

[x99]

Just change on your air filter on a more regular basis than the BMW maintenance plan. The key is a clean filter.

[MA78]

I know that it's not going to make a huge difference, but I figure if its part of a Dinan package it must be worth something. I'd prefer to do more extensive modifications, but you know...warranty.

[bekind]

You will not see the same gains. The Dinan package typically includes a completely new cold air intake to help prevent heat soak, eliminate the OEM baffle and create a smoother flow of air (in theory).

If you just drop a K&N filter into the stock housing you will gain almost nothing and when it comes time to reoil the filter you run the risk of doing damage to your MAF (mass air flow sensor).

[Ant Man]

For the US folks - best bang for your buck will be a remap (tune).

Drop in filters usually only make gains at high rpm which isn't really the point of a 4WD SUV

Most remappers / tuners will have a 4WD dyno, certainly the Jap tuners do to cater for the scoobis and Evos.

Some of the latests BMW engines do not have MAF anymore. The ecu can be target driven and request the engine to suck in the required volume of air it calculates is needed given the circumstances.

[MA78]

Originally Posted by Ant Man

For the US folks - best bang for your buck will be a remap (tune).

Drop in filters usually only make gains at high rpm which isn't really the point of a 4WD SUV

Most remappers / tuners will have a 4WD dyno, certainly the Jap tuners do to cater for the scoobis and Evos.

Some of the latests BMW engines do not have MAF anymore. The ecu can be target driven and request the engine to suck in the required volume of air it calculates is needed given the circumstances.

I've been looking into this.

[bekind]

The N55 motor has a MAF.