I am curious as to how high of an rpm those of you who are running fuel management systems have spun your motors? I have been spinning mine up to 6200 and the bike pulls hard all the way there. That tells me the motor is still making power, however; without having put the bike back on the dyno, I don't know how much further I can spin it and still make useable power. I decided to turn up the wick today and will see how it does turning 7300 rpm.
How high do you spin your motor?
- Thread starter NGOT8R
- Start date
I would like to spin it past 6000 rpm, however when looking at the kinematics of the engine, the piston velocities combined with high side load on the skirts will spell doom for the engine in short order. All three of us have been there unfortunately.
Back to a mid-range cam for me and 5700 rpm red line.
Back to a mid-range cam for me and 5700 rpm red line.
I am gonna get out a couple of hours from now to test it out and see how it does. Going to an Area 51 location and getting it on with a Victory Vision that has cams and an ecu flash, plus a piggyback fuel management system, ignition advancer, modified intake tract and full exhaust. He spins up to about 6500 rpm and has been a contender for a local guy with a Jims 131 motor, so we shall see.
I went out and represented the SG family well tonight. We made two hits (one from a 25 mph roll and the other from 40 mph roll). Race one ended with me out front by 4 bike lengths and race two ended with me out front by one bike length. I was shifting at 6500, during which I discovered that there is no need to spin the motor up to 7300. Having said that, I will lower the rev limiter to 6500 and shift at 6200 during future skirmishes.
Sure, but your scan is missing the unit labels on the vertical axis.
If you don't have the original chart to re-scan or photograph, the dyno operator should be able to email you the run file from the dyno. I can open those with Dynojet software.
Evil with those numbers shift when ever the hell you want. Nobody will be around that beast to see the shift. I must say I would love to have those numbers that bike is a flippen beast.
Hulk, sorry for the dumb question but I would like to better understand your chart.
It has the ft.lbs. on the Y axis going over 2,000 is that correct?
I must be missing something about how this chart is created with the information obtained on the dyno chart.
It has the ft.lbs. on the Y axis going over 2,000 is that correct?
I must be missing something about how this chart is created with the information obtained on the dyno chart.
That is rear wheel torque on my chart. The dyno chart shows engine crank shaft torque as measured at the rear wheel. Rear wheel torque is 9.6 times greater than crank shaft torque in first gear. Each time you shift up, there is less rear wheel torque, do to the change in gear ratio.
