MicroSquirt.com read only forum (Jan.15,2018)

Hi

I have installed an microsquirt on a friends bike wich have an 2 cylinder 1200cc oddfire harley engine with turbo.
It is set up as dualspark.
The software is BG2.890.

The engine runs, but the mixture is all over the place.
The problem seems to be the the mapsensor or the timing when the microsquirt take a sample from the map,
coz the map jumps upp and down in big steps.

The variations in the inlet is very big on this engine.
Is there any good solutions to make the mapreading more stable?.


Regards
Øyvind

Normally what you see should not happen in an even-fire engine, because map IS sampled at the same point in time. But the way the odd-fire is set up, it still samples at the same time as if it were an even-fir engine, and the extra odd-fire advance or retard is handled as a different ignition advance for each cylinder. So this will cause the map to be sampled at the wrong time for the odd cylinder. I will look into seeing what is involved in fixing this for odd-fires in the code. But meanwhile you could try modifying the injector start time number. This determines when map is sampled (just before injection) and by moving it around you may be able to reduce the map variation. For example, if it is now sampling it at a point where it is very high for one cylinder and very low for the other, then moving it to a place where they are more nearly the same would reduce map variation, but may require a little retuning.

Hi
Thanks for the fast answer

I will try your tips.

Regard

Øyvind

Hi

can you please tell me wich menu i can adjust the injector start-time, i cant find it,
but it could be that i need glases


regard
Øyvind

hi

I `ve got an idea that am going to try out.
Am a little into atmel microprosesors, so i was thinking to make an co-prosessor that will sample
the map-pressure with one ADC channel, and on the lowlevel of the "inlet sinus" it will update the timer wich is set as pwm-output.
This way the microsquirt will always see the corect inlet value when it decide to sample the map.
i have the little program ready, so i will tell how this experiment went after i have tryed it out.

Øyvind

That would be the best way to do it; you should see a very large improvement.

Hi

We finally got time to test the co-module that i`we built,
The MAP was wery stable and the bike ran ok, we will start the tuning now

Øyvind

I have built a similar bike, I used a 0.030 restrictor inline with the MAP sensor and used Hybrid Alpha-N from 0 to 2300 rpm blending to 3100 RPM, right before the turbo will come too much into play. I was pulling 75-80 kpa at idle, and idle to medium load used the same bins, works wonderfully now.

Could you be kind enough to post info on your trigger setup and settings?
Friend of mine has trouble getting his bike to run.

Sure, here's my MSQ
I'm running a 12-1 tooth wheel with a VR sensor at the crankshaft
a single tooth cam Hall type sensor fed by 5V vref
I saved the VTR CDI module from the bike, it trigger nice sparks but ditched the control module.
I use dual tables since the rear cylinder likes a richer mixture
I run the Hybrid alpha-N blending from 2300 to 3100 rpm, this is why the VE tables are weird, the bike drives like a charm but does not make it's full power yet, I may work on the engine a bit before I turn up the boost