Help with building your Speeduino, installing it, getting it to run etc.
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By PSIG
#46312
Jcrotts wrote: Mon Nov 09, 2020 2:26 am It's a flat plane crank so each "event" should be 180 degrees after the previous one. If I could fire 1 injector off 2 channels it might work. …
That would depend on which scheme you are choosing. If you plan to offset the injections on 2 cylinders, then I'd look at INJ1 injector (1&4) firing "on-time", and INJ2 firing one injector (2&3) offset. Offset injection will be touchy, as the induction is overlapped. This is the prime issue with Siamese setups, and why alternative options are considered. Some have gone so far as to construct independent-runner tubular manifolds with port dividers in order to side-step the issues inherent with timed Siamese fuel delivery, versus constant-flow systems such as carbs and mechanical injection, as even those are not perfectly balanced. Hence, other options for deep-port (relatively isolated fuel) or TBI (fully-shared fuel).
Jcrotts wrote: Mon Nov 09, 2020 2:26 am… Is it possible to run 1 injector off 2 channels without seeing the magic blue smoke?
No blue smoke worries, but your fuel delivery signals will overlap, botching your actual-vs-calculated fuel flow. If the overlap were consistent, then it would be doable, but overlap charge stealing varies with speed and load. With typical injector sizing and flows it's not an option.

As much of this is unique to your setup, and you need to not only wrap your head around it but know the real-world effects involved in your specific setup; I suggest (IMO) plugging a pair of injectors above your carb throat or in the air filter housing (F1-style down-throat injection), shut off your carb fuel, and do some tests. It's the simplest and easiest first-step, and what you learn in a couple days should go far in guiding you to the better direction. Just ideas, and that's entirely up to you. Good luck!
By Jcrotts
#46328
As for the trigger setup: For arguments sake, let's say the flywheel is a non-360 trigger wheel with no missing teeth.

Could I set it up as a non-360 dual wheel setup, with the distributor points acting as the camshaft wheel "teeth"? Shave the points lobes down in the distributor, and lock out ignition advance, to act as a 4-1 or single tooth cam input for cylinder position data?? Ignoring the issue of timing accuracy for now, would the system view it that way?
By Jcrotts
#46332
I just counted, and there are 135 teeth on the flywheel. 2.67 degrees per tooth. That's rounded up, of course . If it was divisible by 360 I would have some INSANE precision in timing.
By Jcrotts
#46348
Just had an epiphany: If I use TBI I dont need specific cylinder data. If I feed 1 coil to the distributor cap, it controls which cylinder fires, and with TBI it doesnt need a cylinder either. All it needs to know is fire the coil at X degrees and inject at X degrees. Again, doesn't matter which cylinder. This would simplify setup SO much. Sometimes the simplest stuff flys right over my head. If the non 360 decoder will work I'm good to go for testing.
By Jcrotts
#46360
:shock: Holy sh... again,the simplest stuff flies right over my head. Do I need to butcher a distributor for cam input, or can I use it as a 4 "tooth" wheel? I have a spare, so it's no big deal either way.
By apollard
#46361
Jcrotts wrote: Tue Nov 10, 2020 3:06 pm Just had an epiphany: If I use TBI I dont need specific cylinder data. If I feed 1 coil to the distributor cap, it controls which cylinder fires, and with TBI it doesnt need a cylinder either. All it needs to know is fire the coil at X degrees and inject at X degrees. Again, doesn't matter which cylinder. This would simplify setup SO much. Sometimes the simplest stuff flys right over my head. If the non 360 decoder will work I'm good to go for testing.
Exactly. You don't have a modern engine, and it isn't going to be a fuel efficient engine or horsepower monster. Complications like per cylinder injection and timing that is to the last degree won't make much (if any) difference. Getting reliable, tunable timing and control over average fuel charge will make a difference. I faced the same choice with my boat project. I went TBI and distributor and have never regretted it. It is more fuel efficient than a carb and easier to tune, but it's not a modern engine and getting the last little bit of efficient performance would be an exercise in diminishing returns.
By apollard
#46362
Jcrotts wrote: Tue Nov 10, 2020 7:30 pm :shock: Holy sh... again,the simplest stuff flies right over my head. Do I need to butcher a distributor for cam input, or can I use it as a 4 "tooth" wheel? I have a spare, so it's no big deal either way.
In my opinion - if you have a distributor that is in good shape, lock the timing and use it as a low res trigger w/o mods. Single coil and distributor for cylinder choice will work fine here. A degree or three of variation won't affect your engine / application much. Control of fuel mixture will be much more important.
By Jcrotts
#46365
Ok. Audi 135 for trigger off flywheel. Hall or VR w/ GM 7pin module for crank pickup. Distributor as is, points for cam. I'm thinking LS coil, built in driver. TBI injection. Wideband O2. Can't read per cylinder. Exhaust/Intake is 1 piece cast manifold. It needs to run pretty rich anyway, being a tractor. As long as it's not lean, I'm not too worried.

Sounds like a good start. I have enough parts around here to cobble something together for testing. I think I have a good turbo around here somewhere too... 8-)
By apollard
#46367
If you're going to use a VR, I'd get one of the boards members here have designed. PSIG has one that will read practically any sensor reliably. Of course, if you already have the GM module, that price can't be beat...

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