I need an exact definition of this.Would someone put it into words for me. Thanks in advance.

Fuel Injector Duty Cycle

Duty cycle refers to the amount of time an injector is held open vs. the amount of time available at a certain rpm before the next injection event happens and is expressed as a percentage. The electrical characteristics of injectors make it undesirable to drive them at 100% duty cycle due to heat distress on the injector windings and drive circuitry. We like to limit maximum duty cycle to a value between 70 and 85% for most applications. If we take our figure of 400 hp and multiply it by 0.8, we get a maximum figure of 320 hp. Working back, we can determine that the injector duty cycle should only be about 50% on our example engine with these injectors, so we are very safe here.

We can calculate hp and fuel consumption from duty cycle directly using our assumptions above and can even develop rough hp and torque curves using the DUTY readout from your SDS programmer.

At 3000 rpm and full throttle, we stabilize rpm momentarily by using the brakes. Wait 2 seconds for any acceleration enrichment to stop which affects duty cycle. Let's say that the duty cycle reads 15% on our example setup. We need to take our 400 hp figure and multiply by 0.15. This gives us 60 hp. Working back, we can figure that we are burning about 30 lbs./hr under these conditions. This can be converted to gallons per hour and even MPG if velocity is known. This procedure can be used at 500 rpm intervals to develop a hp curve.

Torque output can be calculated from hp by using: Torque = 5252 times hp divided by rpm. Conversely, if torque is known from a dyno test, you can play with the numbers and calculate hp using HP=torque times rpm divided by 5252. In our example, torque works out to 105 ft./lbs. It should be noted that most properly mapped engines will run at a lower BSFC figure during cruise conditions because of the leaner AFRs generally used here. You could use a BSFC figure of 0.38 to 0.45 here if the AFRs are in the 16 to 17 to 1 range as indicated on your mixture meter.

 

Oh.
My.
Goodness.
:lol:
man, I know sometimes ya gotta read and RE-read to understand something, so I'm so glad I found this.

after installing deatschworks 650cc (man, what a deal I got), sr-30, 255lph walbro AND an APS t/i pipe, my afr is rich, costing me $.>12 tho, so I'll live.

doing research to see about latency et cetera. yes, math is valuable