Any general discussion around the firmware, what is does, how it does it etc.
User avatar
By MichaelAxelrad
#57578
I need to start my VW Type 1 engine (aircraft) by hand cranking. It is equipped with a 35 & 1 coding wheel and four LS type ignition coils.

There are provisions for priming before cranking. My problem is to get a spark after approximately 90 degrees of revolution. (9 teeth before missing tooth)

The decoding code software is a little dense for me to effectively modify. If one could guide me through that, it would be a great help.

Alternatively during cranking I could use accessory hardware to fire the pairs of cylinders at the appropriate angle (TDC 1&3 4&2)- then disable the circuit when running.

Your help and opinions will be greatly appreciated.

michael
By LAV1000
#57579
Michael,
I read airplane engine, if you stil use it to fly make sure you have a backup system in case the speeduino fails !!!

35&1 can you explain more about this ?
The way I understand it, it has 35 crankteeth and an additional teeth signal from camshaft or distrubitor.

Ignition after 90 dergrees revolution ?
Most engines need a spark around TDC.
If you need this to prevend kickback from propellor, then ther are other possibilities.
In Tuner Studio you can set a starting ignition timing.
This way ignition is retarted at starting ( hand cranking) and gets to its normal settings when running.
By JHolland
#57583
Are you saying that you want the engine to fire within the first 90 cam degrees? a 35+1 will always have to pass the missing tooth before it will synchronize, I would think that you would need a cam sensor, something like a Denso optical sensor where you can measure the length of the slot to determine which cylinder you are on.
User avatar
By digmorepaka
#58672
MichaelAxelrad wrote:Alternatively during cranking I could use accessory hardware to fire the pairs of cylinders at the appropriate angle (TDC 1&3 4&2)- then disable the circuit when running.
Currently semi sequential on half sync is implemented, if you run it with 0 skipped revolutions it starts the ignition and injection as soon as it half syncs.

lsdlsd88 wrote: Fri Sep 23, 2022 6:49 pm why would you even need an ecu for that engine???

mechanical things always work. much safer
Quite the opposite. Electronic fuel injection is a lot more reliable and easier to troubleshoot. This is due to reducing complexity, adding failsafes, and providing a lot more info about what's going on.

What's more reliable?
A COP/wasted spark ignition with only thing moving being a trigger wheel mounted to the cam/crank in front of an inductive sensor

Or a distributor with mechanical rpm+vacuum advance where a membrane can tear from say a backfire, spring can pop from being cold and stress over time(which also changes it's characteristics), a bearing that the position sensor/or let alone the point rides on as the vacuum membrane turns it tightening up, a cap and rotor that builds up oxidation and burns it's contacts every moment it runs?


These things were engineered in and for an era where the something breaks interval of an automotive application was 500-1500km and you carried a toolkit in your car at all times. There is no reason to run such an outdated and unreliable system on something this missions critical when these days EFI is so accessible.
By JHolland
#61889
digmorepaka wrote: Fri Sep 23, 2022 10:44 pm Quite the opposite. Electronic fuel injection is a lot more reliable and easier to troubleshoot. This is due to reducing complexity, adding failsafes, and providing a lot more info about what's going on.
A professionally engineered system, qualified to automotive standards and fully type approved system may well be more reliable. This is an amateur design, the software has bugs, the hardware is not to automotive standards and has a number of faults. There are no safety systems - no memory checks, no watchdog timer, no brown-out reset, no hardware fail-safes, no redundancy, its not an automotive processor, it has no injection current rating, no EC memory, no floating supplies, no analog signal path error detection.....
User avatar
By PSIG
#61893
In-spite of all those shortcomings, I (just me) have had at least equivalent reliability with our hobby-level ECMs as carburetors, while retaining the substantial improvements and benefits listed previously. While I would like to think that care and attention to detail of assembly and installation has much to do with this, and the primary issues involved are mostly in setup rather than continuing operation; I cannot claim that as we have little reliable data to base any conclusions from any perspective.

I think we have better success than if we were making our own carburetors at home. :lol: An equivalent comparison would be a manufactured carb to a manufactured ECM, so I think we do quite well for the comparison. I have left OE ECMs behind with all their proprietary entanglements and configurations for goals that rarely match most of ours. I have run $2000 systems, but I don't see 10x the benefits, for most hobby projects anyway. Speeduino could certainly use some "fixing" of basic faults, and honestly I expected "Gen2" long before now. A bit disappointing after this many years of simple but important fault awareness.

I'll just say that I clearly prefer to run carbs or ECMs that fit the goals best. Most commonly something like this with all the good reasons and faults, to the carbs, tuning and troubleshooting I did previously for decades (and still do). I have my own experience to decide my preferences for myself. That's me. Decide yours. Do your thing! 8-)

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