K&N AIR FILTER
- Thread starter DEL french
- Start date
Like others have said you risk ruining your MAF sensor and then benefits are not sufficient to outway the disadvantages. I fitted one a while ago on my Gen 2 Mini (which doesn't have a MAF sensor). It gave a more throaty sound (but you are unlikely to hear that on a Z4), fuel consumption got marginally worse (but not enough to have any significance) , performance was not changed, insurance went up.
I find cleaning them a pain. The construction appears to be cloth particles held between two fine metal gauzes. They mustn't be blown with an air line and you have to be a little careful washing them so as not to wash away any of the particles. They mustn't be over and under oiled either and oiling them with the K&N kit is not an exact science (squeeze oil out of plastic bottle onto the vanes and look for an even pink colour distribution). They are unlikely to filter out crap anywhere near as good as a decent paper filter.
I wouldn't bother with my Z4. But then again, some love them and swear by them.
I find cleaning them a pain. The construction appears to be cloth particles held between two fine metal gauzes. They mustn't be blown with an air line and you have to be a little careful washing them so as not to wash away any of the particles. They mustn't be over and under oiled either and oiling them with the K&N kit is not an exact science (squeeze oil out of plastic bottle onto the vanes and look for an even pink colour distribution). They are unlikely to filter out crap anywhere near as good as a decent paper filter.
I wouldn't bother with my Z4. But then again, some love them and swear by them.
In resurrecting this post I was referring to the pipercross filter and not the K&N one. The pipercross one is not oiled so no risk whatsoever to the MAF. There is lots of views about K&N but no one previously has referred to the pipercross filter. I didnt expect to add to performance, its just that car felt more responsive and pipercross filter is not that expensive. Probably not conclusive in any way but emission test at MOT were significantly lower than previous years with the standard paper filter.
Rio Ranho, NM
I have used K&N filters for about 40 years and don't regret it. I have never seen one come out of the box with any enough oil to effect the MAF sensor and if there was, a squirt of MAF sensor cleaner allowed to fully dry would take care of that. If you keep your car for three years or so, you would easily recoup the cost difference of yearly paper filter replacement. You generally don't have to clean the K&N filters every year. People generally clean them too often. As for performance, the K&N is definitely less restrictive than a conventional paper one. This itself won't gain you much power. On ram air situations, the K&N will begin to show benefits. I have a 2003 Z4 3.0L engine and it comes with ram air stock. I have put a simple plate in front of the air intake to divert additional air into it and insulated the whole path into the engine. In this situation, I have increased the air volume, temperature and thus air density. Density is the key and with that combination, you do get better throttle response and a hp gain of an estimated 1 to 2% which is noticeable. It did cost me about $100.00 in the deflector plate and insulation and about two hours of my time. Judge for yourself if it is worth it. My estimate is based on a lot of information fed into to AI.
I had a Piper cross air filter but didn't notice any difference . I then had problems with emls and garage carried out a number of tests but couldn't find anything. They suggested maf was breaking down under load and noticed I had the Piper cross air filter. They put it in the bin and replaced with the paper one and said you can get all manner of problems with go faster air filters. Turned out it was the MAF sensor but whether or not the go faster filter caused it is any bodies guess. Car is very low mileage so you wouldn't expect maf to break down. I will stick with paper filters from now on.