Dyno Run

[alexanderfoti]

Hi all

today I had a dyno run done on my diesel bike, all standard engine apart from K + N air filter and BP ultimate diesel. 10.12bhp @3117 rpm and 18.85ft/lb @ 2411 rpm all at the crank! Not bad figures I think.

The dyno graph and video is embedded in this post on my site.

http://fotifixes.com/2012/10/13/diesel-bike-dyno-run/

[pietenpol2002]

Great to see the results of your bike on the dyno. And thanks for sharing the results with us. You note that it's at the crank. However, it would seem that the figure is taken from the rear wheel. How then would you arrive at the hp rating at the crank? Or, how do you accurately allow for the losses from primary drive, gearbox, and final drive to arrive at an accurate output at the crank. Either way, to me it seems surprising that the 406cc Yanclone is capable of producing in excess of 10 hp.

[alexanderfoti]

Many thanks

The figures are adjusted to produce crank figures, as it says DJHP Corrected power on the bottom of the dyno graph, I looked this up and the documentation says:

The DJHP Correction option box, when ticked, will display the Power and Torque data in
numbers that relate to other self proclaimed “Industry Standard” dynamometers. These
numbers are related to an estimation of ‘Engine Crank Power’

Granted it doesnt take into account the losses in the transmission, but the run was done in 4th gear, and the box is 1:1 when in 4th, so the losses are minimal.

[pietenpol2002]

That's helpful to know that those figures are adjusted for typical losses. Even if they're not entirely accurate, the engine is still producing something close to 10 hp. That's encouraging to know given that they're often thought to produce little more than 9 horse.

[alexanderfoti]

My thoughts exactly, I'm sure at lower power outputs the margin for error on the dynos is higher, but i'm happy with that, means the engine is in good health. Bit of a shame they didnt use a larger rev range though. Would have been good to see where it falls off etc.