airbox mods

[milkman]

As the air heats up the molecules expand, so cold air basically has more oxygen molecules in the same volume of air ie its more dense. So more oxygen, more effient burn, more power. When your talking in 1000th's of a second in nthose drag racers it makes a big diff.

Thanks for all the info. Where it seems almost standard on other bikes and cars, it would seem BMW have the intake largely sorted. The K&N come into their own against standard filters in dusty environments, and life span is unmatched.

[MrRiden]

I was all set to ditch the airbox and go with pods or even velocity stacks but then I gave this article some consideration. http://pweb.jps.net/~snowbum/InExTuning.htm Now I'm looking for the unequal snorkels instead.
Rich

[Semper Gumby]

I bought the K&N square filter for the stock 1980 airbox so I wouldn't have to buy filters once a year.  One less thing to buy over and over and over.....

[wiemer]

Rob,

I have the same "clamshell box" as your bike.  
I am going to change the crankcase vent too in the way you indicated.
No more moist dripping into the right carb.
And nice, an extra hose. Most of my bikes had such an open hose; even my MZ has one, to ventilate the gearbox  

Thanks for the pics.

wiemer.

[Rob Valdez 79 R65]

Credit where due:

It was not until I visited Nathan's shop at Boxerworks in Georgia (USA), where I saw an example of a hose exiting the airbox at this location.  I may not have ever thought of it, myself.  It was on one of his conversion (/2) machines.  (I can't believe I didn't take more pictures while I was there.)

Before that, my hose was a convoluted mess made up of the original breather hoses that I cut up to exit outside the starter cover/air intake horn on the '79 and earlier engines.  To that was attached an automotive heater hose that ran down the left side of the bike and was zip-tied onto the swingarm.  

I was teased about it at the BMWMOA national rally in Lima, Ohio; so I decided it was time to clean it up.  Someone suggested a garden faucet tap would be appropriate at the end!

Also, my virtual friend vanzen provided inspiration.

http://www.rockerboxer.com/albums/album_image/1415721/550671.htm

(in this picture you can see the filter near the tail light)
http://www.rockerboxer.com/albums/album_image/1415721/593255.htm

I am still looking for some of that nylon reinforced hose of the right size, like vanzen is using.