2 squirts/cycle with 3 cylinders?
Moderators: jsmcortina, muythaibxr
2 squirts/cycle with 3 cylinders?
I'm currently running my BMW k75 motorcycle with 2 squirts/cycle, basically making it think the bike is a 2 cylinder (I'm running fuel only, triggered from one of the wasted spark coils). The OEM Bosch ran 2 squirts like this too, and it runs well, it averages the fuel injected over the cycle, which is better for low RPM and takeoff. I would like to preserve this when I convert it to fuel/spark control. It seems it would be useful to allow this configuration for odd cylinder engines, like 3 or 5 cylinders. I tried running it as a 6 cylinder, but it wouldn't read the RPM right even with wasted-COP mode.
Re: 2 squirts/cycle with 3 cylinders?
What sort of trigger wheel do you have? You could run sequential.
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QuadraMAP Sensor Module -- PWM-to-Stepper Controller -- Dual Coil Driver
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Coming soon: OctoMAP Sensor Module
TTR Ignition Systems
Re: 2 squirts/cycle with 3 cylinders?
Currently, just doing coil negative trigger. I'll be putting in a crank mount missing tooth wheel. I could do semi-sequential with that, but I would have to add another injector driver.
Re: 2 squirts/cycle with 3 cylinders?
You have a triple running as a coil -ve twin?! That must do strange things to the rpm reading ...
You might take a look at the jbperf 4 channel injection and ignition board.
You might take a look at the jbperf 4 channel injection and ignition board.
Temporarily shut down - back soon!
QuadraMAP Sensor Module -- PWM-to-Stepper Controller -- Dual Coil Driver
Coming soon: OctoMAP Sensor Module
TTR Ignition Systems
QuadraMAP Sensor Module -- PWM-to-Stepper Controller -- Dual Coil Driver
Coming soon: OctoMAP Sensor Module
TTR Ignition Systems
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Re: 2 squirts/cycle with 3 cylinders?
Actually, with an odd number of cylinders you can't do semi-sequential with a crank-only signal.
And you can't do 2 squirts/cycle because you have 3 trigger events per cycle. So you would have to fire an injector once per 1.5 trigger event which is obviously not possible. You can use 1 or 3 squirts/cycle.
Jean
And you can't do 2 squirts/cycle because you have 3 trigger events per cycle. So you would have to fire an injector once per 1.5 trigger event which is obviously not possible. You can use 1 or 3 squirts/cycle.
Jean
Re: 2 squirts/cycle with 3 cylinders?
dontz125 wrote:You have a triple running as a coil -ve twin?! That must do strange things to the rpm reading ...
You might take a look at the jbperf 4 channel injection and ignition board.
It's dead accurate. It's a 3-coil wasted spark system. The MS gets the expected number of pulses for a 2 cylinder wasted spark (1 per rotation).
What about running it as a 6 cylinder? It's a symmetrical half of a 6. With wasted spark, it would still be 3 sparks, 1 injection per revolution. I could even do batched sequential like that, batching the "pairs" of cylinders. I would do 3 squirts per rev, but the pulsewidth gets a bit small at idle, and the duty cycle approaches 85-90% at higher RPMs/Loads.