Dyno Sheets

Mikey D

Registered
Thanks for asking RiderCoach!

I tagged these onto the MMI Thread but alas, they were lost to obscurity.

OK here they are!

Sorry about the B&W & sideways image.  I'll figure out these computers someday! :blush

This is a pair of 4th gear roll on runs.  It takes a few runs to get the hang of operating the dyno.  (Yeah, I know, it's only 2 buttons)

You have to watch the computer screen, stabilize the starting RPM (4000 in this case) and the consistantly roll on the throttle.

You can see I still didn't have the hang of it.

But hey, 161 HP and 100 ft/lbs of torque!  

Not shown here is the F/A ratio, which incidently showed Suzie running a tad rich.  I was told that with a power commander and a new air filter, we could map out the small flat spot, lean it out a tad and maybe get another 5 or 6 HP.



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post_6_95302_Roll_on.jpg
 
And one I have never heard of...

This is a Negative Horse Ppower test. It is supposed to tell you if you have engine or driveline problems. With the roll on test, assuming you have some jiggilies in the top end of the graph, you do one of these and you can tell if it is fuel/electrical related or engine/driveline related.

You start with a standard 4th gear roll on, then when you hit redline, turn off the ignition, with the throttle still WFO.

The bike was initially making a bunch of power and transmitting it to the roller. Now the inertia of the roller is driving the rear wheel, driveline and engine of the bike (hense the negative HP). Any juggles in the peak of the graph will be mirrored at the bottom of the graph (where it starts climbing back to zero) and indicate a mechanical problem.

You can also do it with the clutch pulled to eliminate the engine from the equation and isolate driveline problems.

You are supposed to see a nice smooth curve like this one. The bobble at the far right is operator error. (that's me!)

I'm not posting the all gear test as it is too aparent that I don't know what the rev limiter sounds like!
tounge.gif
Besides, the instructor said that I could do it for fun but it is unnessary (sp?) on a fuel injucted bike.
 
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