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Old 27-05-09, 02:43 PM   #41
yorkie_chris
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Default Re: Got LOTS of Dyno data, want data on a particular model bike?

Quote:
Originally Posted by fizzwheel View Post
Not really is it...
I'd say that depends how the power is being delivered, it's not all big number.

Quote:
Originally Posted by ThEGr33k View Post
Well looking at the numbers for DIN correction they sound about right. I agree thought that crank BHP is a load of rubbish, utterly useless. At least RWHP take into effect all losses through the Gearbox etc.

Crank HP would benefit the big Twins as they have heavy gearboxes to deal with two bix power pulses where 4cylinders have 4 smaller ones so can use lighter boxes.
By that analogy I'd say that knowing the RWHP would be even more important.

Also, a physically large and strong gearbox is not necessarily inefficient. It will have a lot of inertia, but a dyno run is pretty close to steady state conditions when you think about the inertia of the gearbox shafts and cogs compared to the inertia of a heavy back wheel, tyre, crank and half a tonne of solid steel dyno roller!

RWBHP is the only meaningful measurement. Anything else is "numbers down the pub"
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