In search of better Air Filtration

[prwatts]

Hi, this may not affect most of you but out here in Saudi Arabia one dust storm can block an air filter.
I think the OEM Air Filter is lacking - it has a small frontal area and has been further blanked of with the plate with holes drilled in it (inexplicably) and has tight paper pleats - all of this must severly retrict air flow.
Then there is the 'trunk' or 'snorkel' or inlet pipe with a front that is about 2" in diameter, for a 1200cc engine suupposedly designed to rev?

I confess I cannot see the wisdom in this design so maybe someone can explain it to me, and what we can do to improve matters? Is the snout just to stop intake roar?

I bought a costly K&N Air Fil;ter and it has actual pin-prick holes that you can see through when you hold it up to the light. Apalling ! SAE Fine Test Dust goes down to 1 micron - those holes are WAY bigger. 45 pounds down the drain.

How about a washable foam filter like the MX guys use - eg Pipercross?

Many thanks
Peter

 

[Martyn H]

Hi, this may not affect most of you but out here in Saudi Arabia one dust storm can block an air filter.
I think the OEM Air Filter is lacking - it has a small frontal area and has been further blanked of with the plate with holes drilled in it (inexplicably) and has tight paper pleats - all of this must severly retrict air flow.
Then there is the 'trunk' or 'snorkel' or inlet pipe with a front that is about 2" in diameter, for a 1200cc engine suupposedly designed to rev?

I confess I cannot see the wisdom in this design so maybe someone can explain it to me, and what we can do to improve matters? Is the snout just to stop intake roar?

I bought a costly K&N Air Fil;ter and it has actual pin-prick holes that you can see through when you hold it up to the light. Apalling ! SAE Fine Test Dust goes down to 1 micron - those holes are WAY bigger. 45 pounds down the drain.

How about a washable foam filter like the MX guys use - eg Pipercross?

Many thanks
Peter

Why not accept the manufacturer knows a fair bit about what they're designing, & leave well alone ?

 

[Deleted User O]

Why not accept the manufacturer knows a fair bit about what they're designing, & leave well alone ?

If manufacturers knew what they were doing would there be any need for new models

 

[Monty]

Why not accept the manufacturer knows a fair bit about what they're designing, & leave well alone ?

Final drive, anyone?

 

[Mr K]

Maybe check on Advrider, as they have deserts over there.

 

[prwatts]

Maybe check on Advrider, as they have deserts over there.

Thanks - anyone who has looked at the air filter has to wonder why it is so restricted. I will go to AdvRider.

 

[prwatts]

Why not accept the manufacturer knows a fair bit about what they're designing, & leave well alone ?

I take your point and the manufacturer has access to a lot of data we don't, but he is constrained by many other factors and budget. The OEM Filter has a plate across the front with holes drilled in it that reduces the frontal area by at least 1/3 maybe more. That intrigues me as it is counter intuitive to restrict intakes - uless you want to restrict a 500cc bike to 33BHP like the British system for young riders.
Therefore BMW have a reason to restrict the intake - either hold the power at a set level so they can gradually increase it later, or becaue some other part of the bike is at the limit and would not like 10% more power. EG FD ??? in which case I don't want that 10%.

And I am not certain BMW are such perfect engineers - IMO they over-complicate things too much sometimes for small seemingly unnecessary gains. I much prefer the Yamaha shaft drive on my old XJ900 years ago, much simpler and neater. It never gave me hassles.

Anyway, i am curious and the OEM Air Filter seems inefficient to me - and it blocks up quickly.

And how about that snorkel/trunk....

Peter

 

[F104]

My filter has a simple cross in front of it, less than 10% of filter space, no drillings. I think it's only function is to keep the filter edges in place when you slide the locks on

Nothing wrong with pleat style filters, they're used everywhere. But in my BMW 320d it's upside down, so on idle / vibration the large particulates (sand, leaves, insects..) fall down. And yup every 5000mls there's a fair bit of whatever on the bottom of the air filter box. On the GS(A) it's a side entrance filter though, whatever goes in the filter element, stays in there.

Aside from that look at this thread, I had to conclude the snorkel/snout is not bad. It could be improved IMHO but that's another discussion
http://www.ukgser.com/forums/showthread.php?t=260044

If I were in a high dust area i would consider a two stage filtration. First one a simple cone/foam filter onto the snorkel (there's a fair amount of room in that area, at least on the 2010 bike w/o charcoal thingy), and secondly the orginal BMW filter as fine /back-up filter .

I don't think (on average) two filters are going to increase intake restriction. Surely, compared to one original new filter restriction will be higher. But what after 1000mls in a high dust environment, where most of the dust is captured by the first filter, can simply fall out or be cleaned, and the BMW one stays fairly clean

just my thoughts

 

[prwatts]

My filter has a simple cross in front of it, less than 10% of filter space, no drillings. I think it's only function is to keep the filter edges in place when you slide the locks on

Nothing wrong with pleat style filters, they're used everywhere. But in my BMW 320d it's upside down, so on idle / vibration the large particulates (sand, leaves, insects..) fall down. And yup every 5000mls there's a fair bit of whatever on the bottom of the air filter box. On the GS(A) it's a side entrance filter though, whatever goes in the filter element, stays in there.

Aside from that look at this thread, I had to conclude the snorkel/snout is not bad. It could be improved IMHO but that's another discussion
http://www.ukgser.com/forums/showthread.php?t=260044

If I were in a high dust area i would consider a two stage filtration. First one a simple cone/foam filter onto the snorkel (there's a fair amount of room in that area, at least on the 2010 bike w/o charcoal thingy), and secondly the orginal BMW filter as fine /back-up filter .

I don't think (on average) two filters are going to increase intake restriction. Surely, compared to one original new filter restriction will be higher. But what after 1000mls in a high dust environment, where most of the dust is captured by the first filter, can simply fall out or be cleaned, and the BMW one stays fairly clean

just my thoughts

I am thinking the same - remove the drilled plate in front of the filter and put a 10mm oil wetted open cell foam on it to give 2 stages of filtration. It will be held in place by the snorkel. I am also looking at the snorkel to put an Outerwear over the front (microfilter mesh) If I can find a spare one I will cut it down for further experiments.

Thanks for the thoughts.

 

[Steptoe]

and put a 10mm oil wetted open cell foam on it to give 2 stages of filtration. .

You're letting your imagination run away with itself.....

Oil wetted filtration - in a desert enviroment

Once one layer of sand has stuck to the oil what happens next.


Leave the original dry filter in place, do not use a a K&N.

 

[prwatts]

You're letting your imagination run away with itself.....

Oil wetted filtration - in a desert enviroment

Once one layer of sand has stuck to the oil what happens next.


Leave the original dry filter in place, do not use a a K&N.

Yes, I understand, but that is what all MX bikes have - maain reason is to be able to clean it myself. Most of the time there is no problem but one dust storm can fill a paper filter.
I got quite a good answer from a fella on R1200GS.info
I will continue my quest and many thanks for the candor.

Here is a video clip of an amazing sandstorm - admittedly they do not happen like this that often, but I have been in one - pretty scary.

http://cutt.us/64u

Peter

 

[Pukmeister]

I lived in Western Australia and used a K&N on my 1200 for 15 months. Fine sand was blowing around every day (I didn't venture off tarmac on the GS.)

I washed and re-oiled the K&N every few months unless the sand really got badly blowing about, never had a problem and never saw any dust or debris inside the airbox.

Plenty of folk seem keen to knock K&N for some reason, yet they were developed for baja racing ?

Currently running the same K&N on my latest 1200, I clean and re-oil every 6 months in UK climate along with other maintenance checks eg tappets.