Re: Air Filter Test Results

[Ben Barkow <dr.ben@xxxxxxxxx>]

Many thanks for comments on air filter test report. As per Wayne's  
suggestion, the latest version has nice badly-needed charts which put  
all in graphic perspective and much re-writing and enlargement.

http://bigmail.ica.net/users/barkow@xxxxxxx/Ben's%20bike%20files/

Also newly posted is a text about drilling out the mysterious R1100S  
cross-over baffle! Any other models have that weird baffle hidden  
there? What is it there for? Debaffling the baffling baffle releases  
grunt HP. Own a Dremel or round hand file?


I point out that the R1100S K&N does NOT flow well (even when clean and  
dry). The SJ PowerFilter is also oiled cotton gauze but much larger and  
flow-benched; but it must pass a proportionately greater amount of dirt  
than the K&N. Doesn't anybody have a spare somewhat used stock R1100S  
filter to send me for testing? Or a PowerFilter loaner?

True, as my numbers show, the long, cinched R1100S snorkel has large  
resistance - comparable to a filter. But an enlarged home-made snorkel  
has nearly as much resistance. I haven't tried it, my best guess is  
that removing the snorkel is a good move although that may increase  
(white) intake noise (a leading BMW criterion if not one all bikers  
care about) and no longer be breathing the coolest air (hard to say if  
this matters on the highway or in traffic jams).

It hardly bears repeating: of course you can't free-up breathing and  
expect improvement unless you have adjusted other things. The  
shortcomings of this Eilenberger test (and generations of one-variable  
experiments) have been thoroughly aired elsewhere.

As much as I respect Steve Makohin, I do not believe in being a passive  
consumer of bikes. As mentioned earlier, my criteria and BMW's are  
sometimes different. Some of BMW's choices (like adding the HP in the  
new R1200S in the street-useless range above 6500 rpm) are driven by  
their marketing department, eh. Is that where you want your HP, Steve?  
I might want to make different trade-offs, say, between brake  
"strength" and pad longevity. Anybody out there think I should not make  
informed aftermarket choices with respect to brake pads? Tires? Oil?  
Windshield.... air filters?

Cheers.

Ben                                                                      
                                               
Ben Barkow, Toronto... 40 seasons on Beemers, 45 as a biker

1961 R69s/rod, 1967-1999... really sup'ed up and fast

1984 R80RT/rod, 1998-2005  5 extra peak ponies in a wider flatter power  
band,
   much modified 2-into-1 exhaust, CR 9.5, Keihin PJ 34mm oval carbs,
   Uni filter, dual-rate springs with cartridge emulators, BT45/S11,  
Saeng fairing

1999 R1100S, 2004- Leo Vince exh, JetHot coatings, Techlusion 1031,
   large sticky foam filter, TB balance tube, debaffled exh xover, 12%  
reduced front spring, 26 inch windscreen, air horns, Diablo Stratas

------------------------------