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Yoshi · 06-13-2008, 05:42 PM

Hello all,
Let me explain something...

Regarding to the VSS parameter, it is always consistent or proportional to driving distance. 1% error is always 1% error regardless on a city or highway driving.

Regarding to the injector parameter, it's another story.
On my Toyota Prius, I see approx 2msec idling pulse width, 4msec cruising and 8msec accelerating.
Is the fuel consumption is proportional to the pulse width? NO!
We have to know the injector's mechanical delay. In my research, they are between 0.3msec and 0.7msec.
My original SuperMID M-1 design, I thought I should have this parameter as variables. However, I set it 0.5msec and took a lot of fuel consumption data on a city and highway driving, then I saw cosistent results within 1% variance.

I don't know the 0.5 msec is exact one or not, but there is a certain one on that. You'll see more than 1% inconsistency without it.
My recommendation is use this 0.5msec delay to see a stable results.

Regards,
Yoshi

PS. BTW, an oscilloscope does not help this.

06-13-2008, 05:42 PM	#273 (permalink)
Yoshi SuperMID designer Join Date: Mar 2008 Location: Yokohama, JAPAN Posts: 37 Thanks: 0 Thanked 13 Times in 2 Posts	Hello all, Let me explain something... Regarding to the VSS parameter, it is always consistent or proportional to driving distance. 1% error is always 1% error regardless on a city or highway driving. Regarding to the injector parameter, it's another story. On my Toyota Prius, I see approx 2msec idling pulse width, 4msec cruising and 8msec accelerating. Is the fuel consumption is proportional to the pulse width? NO! We have to know the injector's mechanical delay. In my research, they are between 0.3msec and 0.7msec. My original SuperMID M-1 design, I thought I should have this parameter as variables. However, I set it 0.5msec and took a lot of fuel consumption data on a city and highway driving, then I saw cosistent results within 1% variance. I don't know the 0.5 msec is exact one or not, but there is a certain one on that. You'll see more than 1% inconsistency without it. My recommendation is use this 0.5msec delay to see a stable results. Regards, Yoshi PS. BTW, an oscilloscope does not help this. Last edited by Yoshi; 06-13-2008 at 05:48 PM..