Airbox question

[Boycie1150]

My bike has the original clamshell arrangement on it, and I must say, it makes a lovely induction roar when the throttle is wound back. Sounds like a Ducati!!! Well, to my mind it does, anyway!! ;


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I'll get me coat.  

[montmil]

Anyone notice the two air intake snorkels are different lengths? At least they are on both my R65s.

Monte

[tvrla]

Never noticed them being different lengths - one is larger than the other, though.

[montmil]

Anyone notice the two air intake snorkels are different lengths? At least they are on both my R65s.

Monte

Never noticed them being different lengths - one is larger than the other, though.

Stand corrected. Was reading about variable length intake tracts on some of the new sport bikes and carried that thought over to my R65s. They have different size/area/volume snorkels. Wondering if this is a static tuned intake?

The intake snorks are certainly blocked from any straight-line air flow.

Disregarding performance issues pro and con, I believe the aft mounted alloy airbox/intake is a beautiful design.

Monte

[clonmore1]

Barry,

You don't build wings for Airbus by any chance do you over in N Wales on the border?

All this talk of pitot tubes makes me wonder... 8-)

You certainly sound like an engineer!

[Bob_Roller]

Anyone notice the two air intake snorkels are different lengths? At least they are on both my R65s.

Monte

If I remember right, it was for mid and high power, I guess BMW saw some benefit in doing it .

Also the intakes are different on the R80 and R100 bikes as well, all of the airbox tops will fit on the bikes of the era, I don't know if you could tell of any real world difference in performance or not if you put a different one on your bike .

[Barry]

Barry,

You don't build wings for Airbus by any chance do you over in N Wales on the border?

All this talk of pitot tubes makes me wonder... Cool

You certainly sound like an engineer!  

Wish I did. I'd love to have worked in the Aviation industry. They have such high standards of engineering. I am an Engineer and originally trained in Instrumentation at a time before electronic instruments were common.  All sorts of differential pressure devices were used to measure flow and velocity in gases and liquids.

About the snorkels. I'd always assumed that because it's a tuned system that employs reflected pulses in the same way as an exhaust system, the different lengths were targeted to reinforce torque at 2 different rev ranges. A bit like a simple version of the variable length inlet systems fitted to some modern cars. longer inlet tracts improve torque at lower revs.

[tvrla]

The first flat intakes were aluminum. I read something about them at one time but don't recall where. But I have seen them. There was a factory recall mod that involved drilling several holes close to the intake bells, and it had something to do with curing a flat spot - if I recall correctly. Looks kinda funky with the drilled holes, but they're hidden under the tank anyway.