Electronics > Projects, Designs, and Technical Stuff
Catching car's ignition signal
cmcraeslo:
--- Quote from: Labrat101 ---Ok .
I think I know what you are trying to do .
But I have this feeling your are working on a industrial Project .By they way you are keeping 95% of what you are really
doing Not told . You have already invested some very expensive equipment in this update to a ignition system.
--- Quote --- This could be a deal breaker for me for sure.
--- End quote ---
To break a signal is really not Hard but if this is for commercial gain and NOT a hobby etc.
Sorry I am out . TTFN
--- End quote ---
I'm building an ignition cut device (that will allow me to shift while on full throttle on racing gearbox) and it has very sophisticated algorithms to cut it so I need to process the ignition signals very precisely and time it. I have it working fine on a coilpack with integrated drivers, but it doesn't detect the input signal on cars that ECU drivers the coils directly.
Labrat101:
you have a few choices Hi voltage IGBT or FET
I think IGBT maybe a better choice and have them oil mount cooled .
There was a post a few up used Hi voltage Fet's Both will give you the fast response time.
I have never tried this we only build the plug module for diag plug 5 yrs back for standard cars . Auto Test.
if its for racing is it a 4 or 8 cylinder just for interest ..
Photo's word help as well
Mr joeqsmith maybe more your Man ..
Have fun
Circlotron:
--- Quote from: cmcraeslo on August 04, 2020, 01:03:47 pm ---I'm building an ignition cut device (that will allow me to shift while on full throttle on racing gearbox) and it has very sophisticated algorithms to cut it so I need to process the ignition signals very precisely and time it. I have it working fine on a coilpack with integrated drivers, but it doesn't detect the input signal on cars that ECU drivers the coils directly.
--- End quote ---
Yep, you definitely don't want to interrupt the coil while it is charging and consequently get a spark way to early! What about a single relay contact that cuts power to the fuel injectors, controlled by a microswitch on the clutch pedal? Why wouldn't that be good enough? Would the ECU throw an error with that?
cmcraeslo:
--- Quote from: Circlotron ---
Yep, you definitely don't want to interrupt the coil while it is charging and consequently get a spark way to early! What about a single relay contact that cuts power to the fuel injectors, controlled by a microswitch on the clutch pedal? Why wouldn't that be good enough? Would the ECU throw an error with that?
--- End quote ---
It's for racing application where perfect engine cut is needed to unload the gearbox properly. It's for racing gearboxes so no clutch between the shifts. This has to be timed perfectly. What you're describing is a full cut which is something that hasn't been used in this industry for the last 10 years or so (at least the proper ones). Fuel cut on the other hand is very slow and not really useful in my case.
My device is capable of retarding timing of the original ignition pulse, then cutting the spark partially, depending on the configuration and load and making sure that the active spark is evenly distributed among the cylinders and then ramping the restore back to the original ignition timing. It's capable of doing this on up to 6 cylinders parallel, either wasted spark or sequential ignition.
Now, I have this working perfectly on low power/current signal, but when I tried this on a stock car, with regular ignition coil, there was this issue i'm having. So I need to somehow catch this signal's timing when it's not connected to the coil directly.
Driving the coil (output) is not a problem.
joeqsmith:
--- Quote from: cmcraeslo on August 04, 2020, 01:57:49 pm ---
--- Quote from: Circlotron ---
Yep, you definitely don't want to interrupt the coil while it is charging and consequently get a spark way to early! What about a single relay contact that cuts power to the fuel injectors, controlled by a microswitch on the clutch pedal? Why wouldn't that be good enough? Would the ECU throw an error with that?
--- End quote ---
It's for racing application where perfect engine cut is needed to unload the gearbox properly. It's for racing gearboxes so no clutch between the shifts. This has to be timed perfectly. What you're describing is a full cut which is something that hasn't been used in this industry for the last 10 years or so (at least the proper ones). Fuel cut on the other hand is very slow and not really useful in my case.
My device is capable of retarding timing of the original ignition pulse, then cutting the spark partially, depending on the configuration and load and making sure that the active spark is evenly distributed among the cylinders and then ramping the restore back to the original ignition timing. It's capable of doing this on up to 6 cylinders parallel, either wasted spark or sequential ignition.
Now, I have this working perfectly on low power/current signal, but when I tried this on a stock car, with regular ignition coil, there was this issue i'm having. So I need to somehow catch this signal's timing when it's not connected to the coil directly.
Driving the coil (output) is not a problem.
--- End quote ---
If we spun the motor at say 20,000RPM, or 333revs per second, or 3.0ms for one rotation. Using a fixed kill time of 20ms, that's 7 crank rotations. With your six cylinder we get 3 power strokes per rotation or 21 power strokes. For this example, it seems long enough that there may be some gains.
My bike bike shifts under full load with no kill during the start (Robinson transmission). After that, it shifts at 9800 with a 20ms kill. So 20ms/6.12ms or 3 rotations. It's an in-line 4, giving us only 6 power strokes to work with. It's a 5 speed, so only 4 shifts on a pass and again, not all require the kill. Actually, with this type of transmission, using kill could damage it. Similar, if you chop the throttle, you can expect repairs.
Your particular ECM may be looking for a certain combination of di/dt, peak currents and back EMF. I would just measure the coil that is known to work and replicate it as a starting point.
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