Adaptronic Adaptronic 440 wasted spark
03-23-13, 02:03 PM
#1
Adaptronic 440 wasted spark
Wasted vs direct ignition on ign-1a (aem smart coils)
I plan on staring the wiring on the adaptronic, need the extra pwm output,
Plan not to rew the car more than 9k rpm. Any downfall if I run the coils wasted?
I plan on staring the wiring on the adaptronic, need the extra pwm output,
Plan not to rew the car more than 9k rpm. Any downfall if I run the coils wasted?
03-25-13, 03:19 PM
#2
What power level, boost, fuel are you using? Are you planning on making power at 9k or just want overrun to avoid quick up-down shifts for autox or roadcourse use? Basically, if the engine is going to run big boost and live over 6k for long duty cycles, say for roadcourse use, you probably need to rethink the combination.
03-25-13, 06:03 PM
#4
Yeah you can't do that, according to the spec sheet.
The spec sheet says that maximum duty cycle is 40% for the coils.
At 9000 RPM, waste spark, you're firing the coils every 180°. That means every 3.33 ms. At a 40% duty cycle, it means you can only run 1.3ms of dwell time.
Even running direct fire, you can only run them at 2.6ms at 9000 RPM because of the 40% duty cycle limitation (for heat reasons).
In practice you could probably run 3ms unless it's going to be at 9000 RPM continuously; that gives you 40% duty cycle at 8000 RPM, direct fire.
The spec sheet says that maximum duty cycle is 40% for the coils.
At 9000 RPM, waste spark, you're firing the coils every 180°. That means every 3.33 ms. At a 40% duty cycle, it means you can only run 1.3ms of dwell time.
Even running direct fire, you can only run them at 2.6ms at 9000 RPM because of the 40% duty cycle limitation (for heat reasons).
In practice you could probably run 3ms unless it's going to be at 9000 RPM continuously; that gives you 40% duty cycle at 8000 RPM, direct fire.
03-25-13, 07:40 PM
#6
First thing, talk to Adaptronic and see what the ECU does when programmed dwell exceeds 100% duty cycle. You don't want it to keep charging past the spark instant which would lead to retarded timing. I know other ECUs will simply cut the charge time short and fire the coil at the spark instant. I'm sure Adaptronic does the same thing. You just want to make sure.
I like to run 4.5ms with these coils in direct-fire. I setup PFCs at that on the leading up to the 8k range where we start to back off the dwell. What will happen with the Adaptronic, or any ECU with universal dwell is that you will exceed 100% duty around 6500 rpm when trying to charge to 4.5ms. If everything is OK in regards to the first paragraph, you will be ok with short bursts of very high dwell. A 10 second drag pass will be ok. Several long successive pulls on the street may not.
I'd look real hard at a way to free up another output. In direct-fire these coils will do well exactly what you need them to do. As important as ignition is on the rotary, you don't want to take a chance.
I like to run 4.5ms with these coils in direct-fire. I setup PFCs at that on the leading up to the 8k range where we start to back off the dwell. What will happen with the Adaptronic, or any ECU with universal dwell is that you will exceed 100% duty around 6500 rpm when trying to charge to 4.5ms. If everything is OK in regards to the first paragraph, you will be ok with short bursts of very high dwell. A 10 second drag pass will be ok. Several long successive pulls on the street may not.
I'd look real hard at a way to free up another output. In direct-fire these coils will do well exactly what you need them to do. As important as ignition is on the rotary, you don't want to take a chance.
03-25-13, 11:40 PM
#7
The Adaptronic reduces the dwell time to have a fixed off time of 1 ms (for the spark duration). This won't be a problem in direct fire mode unless you want to run 5 ms of dwell at 12000 RPM or something like that; I was more worried about exceeding the 40% max duty cycle spec - but as you say it's a thermal limitation so it would probably be OK except on a road race engine or a drift car (or a stationary engine used for power generation 
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03-26-13, 05:12 PM
#9
The ignition system has to be designed to supply the average power based on the dwell you need for high load, and the typical RPM. You could reduce the dwell at lighter loads to reduce the average heating, but if doing this helps solve a problem, it means that it's a Band-aid because the ignition system hasn't been designed to deliver the average power required.
Probably just as much thought goes into what ECU functions NOT to add as actually implementing the functions that we want to add; the reason being not so much computational requirements inside the ECU but the fact that it has to be documented, and presented in a non-confrontational way to the user / tuner. It's my experience that if it looks too complicated, people will just ignore it, so if I can't see a solid logical argument to adding a function, and I know it will create support headaches (the more complex it is, the more likely people will set it up incorrectly, and the longer it takes to find the problem because there are more settings to check), I have to make the call and decide not to add the feature for the benefit of the other 99.9% of cases.
If I were going to map dwell then the first step would be a table just against battery voltage; but again I can predict that only 0.1% of people would set it up.
The 1280 can do anything; if you wanted to have a 3D map against RPM and MAP for your dwell time, then you could do that; if you wanted to have another multiplier for that table so you have a scaling factor for battery voltage, you can add that as well; if you want it to do that while the engine's cold and then switch over to a 3D map of air temperature vs coolant temperature, and use that as the setpoint for a PID controller to adjust the dwell time then you can do that too. The 1280 is for the cases where people do want to be able to add their own custom functionality.
Thank you!
Andy
