Air Filter

[pride355]

At BMC website, I noticed different dimensions for the filters in US vs Euro M3s.
Any one knows the reason?

Here is the link: http://www.bmcairfilters.com/VisModel.asp

[JOHNBMWM5]

Originally Posted by pride355

At BMC website, I noticed different dimensions for the filters in US vs Euro M3s.
Any one knows the reason?

Here is the link: http://www.bmcairfilters.com/VisModel.asp

No mine fits tight and does not vibrate at all.

[GewoW]

Originally Posted by pride355

At BMC website, I noticed different dimensions for the filters in US vs Euro M3s.
Any one knows the reason?

Here is the link: http://www.bmcairfilters.com/VisModel.asp

there's a little notch of extra plastic where it is anchored I believe

[TPE_toy]

BMC really makes the car breath at high RPM, it's like a mini supercharger.

[holt]

hmm all this talk about rattling kinda makes me worry that my reported "throaty" sound from my MS filter isn't a good thing afterall. But it still sounds cool none the less. I'll see if I can't get a video camera trained on the tach and hopefully the mic will pic up on the sound, and then upload it to youtube or something so everyone can take a listen.

[tom @ eas]

Originally Posted by holt

hmm all this talk about rattling kinda makes me worry that my reported "throaty" sound from my MS filter isn't a good thing afterall. But it still sounds cool none the less. I'll see if I can't get a video camera trained on the tach and hopefully the mic will pic up on the sound, and then upload it to youtube or something so everyone can take a listen.

YouTube wouldn't be helpful since the audio is compressed - this is evidential with exhaust clips. If you're concerned about where the noise is sourcing from, please see a local independent for a professional opinion.

[LateBraking]

Originally Posted by pride355

At BMC website, I noticed different dimensions for the filters in US vs Euro M3s.
Any one knows the reason?

Here is the link: http://www.bmcairfilters.com/VisModel.asp

U.S. has a different airbox design than the Euro one. The Euro Airbox's spring-loaded nub that is inside the airbox is shorter, I believe, so in order to mount a U.S. air filter inside a Euro airbox, you need an adapter, like the one Macht Schnell provides. From what I understand, U.S. now uses the Euro Air Box in their most recent model year M3's.

You can get an adapter, or just get a filter that's sized appropriately. Less parts, less things to go wrong.

[tom @ eas]

Originally Posted by iBeJayKaying

U.S. has a different airbox design than the Euro one. The Euro Airbox's spring-loaded nub that is inside the airbox is shorter, I believe, so in order to mount a U.S. air filter inside a Euro airbox, you need an adapter, like the one Macht Schnell provides. From what I understand, U.S. now uses the Euro Air Box in their most recent model year M3's.

You can get an adapter, or just get a filter that's sized appropriately. Less parts, less things to go wrong.

To be perfectly fair - there's nothing mechanical in an adapter than can "fail".

US and Euro airboxes are one and the same as of 2010.

[kaykay]

Originally Posted by iBeJayKaying

Indeed, we have a carbon filter, and go BMC.

We're supposed to remove this carbon filter, yes?

I'm guessing I just open the air box and snap out the carbon filter, drop in the BMC?

Thanks

[LateBraking]

Originally Posted by kaykay

We're supposed to remove this carbon filter, yes?

I'm guessing I just open the air box and snap out the carbon filter, drop in the BMC?

Thanks

Yep. Buy an aftermarket air filter, take a look at it, open up your air box, find something that looks similar, take it out, replace with aftermarket filter, seal up box, good to go.

[ASU]

Originally Posted by iBeJayKaying

Yep. Buy an aftermarket air filter, take a look at it, open up your air box, find something that looks similar, take it out, replace with aftermarket filter, seal up box, good to go.

I was originially going with the BMC but the shop I will working with recommends AA. Fact is they are somewhat partial to AA as they do most of their tunes and exhaust with AA.

Any experience with AA filters or comparisons with BMC?

[WCH]

If the 2010+ models have the Euro air filter without the carbon layer, is there any point in putting in an aftermarket filter?

[GewoW]

Originally Posted by WCH

If the 2010+ models have the Euro air filter without the carbon layer, is there any point in putting in an aftermarket filter?

Less than pre-2010, but I still believe there is SOME performance gain.

[Mike S]

I had the BMC in mine, but have Dinan now as it comes standard with their charge pipe. Very happy, car sounds even louder now!

[tom @ eas]

Originally Posted by GewoW

Less than pre-2010, but I still believe there is SOME performance gain.

Correct - Oiled filters will have a better flowing abilities than paper-type media.

[WCH]

I'm less concerned about the performance gain but more interested in the sound. I really like the sound of the aftermarket filter.

[tom @ eas]

Originally Posted by WCH

I'm less concerned about the performance gain but more interested in the sound. I really like the sound of the aftermarket filter.

The MS filters add a bit of growl underneath the hood.

[JCtx]

Originally Posted by GewoW

Less than pre-2010, but I still believe there is SOME performance gain.

There might be a bit of a performance gain or none. What you'd gain for sure is a lot more dirt into your engine. The engine is just going to breathe what it needs, and an AA '08/'09 filter (stock but without the charcoal) probably provides all the air a stock engine needs, but without the extra dirt. No free lunch: more airflow (your engine might not need) means more dirt, and any gains (if any) are at the very top of the rpm band. At least where I live (desert), no way I'd risk engine damage over the long run for a few HP, but that's just me. And if you don't believe the many independent tests of racing filters (cotton gauze) vs stock, do your own with a shopvac, by blowing dirt thru the filters with a damp white shop paper towel at the other end. Whoever thinks a racing filter is going to filter anywhere close to a paper one is watching too much TV. Or don't care about his motor . Cheers.

[Richbot]

Show me the data that tells you the small increase in extremely small particles that does make it through an oiled filter is harmful. "Common sense" tells us that dirt (in this case, airborne particulate matter) in the engine is bad. Why? Where is this (very small) grit going? Not in the oil, the seals around the valves and piston rings prevent that. Score the cylinder bores? Sure, maybe, if the dirt is harder than the liners, which most airborne PM is not because hard stuff that is big enough to cause problems tends not to stay airborne for long. The vast majority of crap that gets through your filter (and it's getting through the stock filter too) ends up combusted and/or blown out the exhaust. I bet the people in Iceland with K&N's had to remove and wash theirs along with the rest of the poor saps with paper filters, difference is they didn't have to buy a new one.

Blowing dirt through a shop vac onto a damp piece of paper is flimflam just like putting a pingpong ball in a tube with a couple filters at the bottom and a fan at the top. Salesmanship cuts both ways and I'm not buying what you're selling.

Fact is, I've used K&N's and similar oiled filters on every vehicle I've owned. Never burned a drop of oil or gotten less than 100k out of any of those engines. Fact is, thousands of others have had the same experience.

As for where the gains happen with a filter, that depends on the engine. If there's a restriction at the air filter, it won't only be beneficial at the top of the rpm band, it will be most beneficial wherever the TORQUE PEAK is, and less so in other places. The S65 peaks at 3900rpm and maintains a fairly flat torque curve to 7500rpm. That's not the top of the RPM band, that's, well, 50% of it. So, if there is indeed a restriction at the air filter on these cars (I've seen enough dyno charts to believe it's not a figment of our collective imagination) then it's not just going to help the car at or near redline, as you claim.

[GewoW]

Either way - with an oiled filter, you can remove it and wash it as often as you need, but you are forced to wait for servicing for the stock paper one to be replaced...

That in and of itself is worth it IMO.