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Microrusefi and 6 cylinders

Posted: Sun Nov 01, 2020 2:39 pm
by Gepro
Hello,

I am actually an user of megasquirt, but my daughterboard is fucked, I have some randoms errors, and I am a little disappointed by the price of the repair.

I fall in love of the microrusefi, the tuner studio interface is really customisable.

But, if it is fully customisable, is it possible to use the additionals outputs for full sequential and COP.

I mean, if there is :
x4 high-Z injector outputs
x2 high-current low side outputs for IAC/VVT/other solenoids

and,
x4 5v logic-level ignition outputs
x2 5v/12v configurable logic level outputs (requires resistor changes)

So, technically, I can use 6 high-Z injectors et 6 logil level ignition ouputs.

And, is it possible to use the "x4 low-current low side outputs for relays or warning lights" as PWM output with a transistor behind ? Or is it too slow ?

Thanks,

Re: Microrusefi and 6 cylinders

Posted: Sun Nov 01, 2020 4:02 pm
by AndreyB
microRusEFI is mostly a 4 cylinder ECU, 6 cylinders for microRusEFI would always be a special setup.
On top of the well-documented outputs there are also relatively new four additional channels implemented via two VNLD5090.

With those four VNLD5090 channels we can definitely run 6 cylinders in batch mode (remember per-channel current limitation puts us at the edge if we attempt 6 cylinders in batch mode via TLE8888)

My theoretical concern is running 6 injectors using not the same kinds of transistors. One day someone should do some flow bench testing to compare TLE8888 injector behavior with VNLD5090 injector behavior. Only once we have some definitive experiment confirming that mix and matching transistors works well I would be comfortable recommending microRusEFI for 6 cylinders sequential.

Also there is an opinion that no one needs sequential injection in aftermarket ECU considering how aftermarket tunes are the weakest chain in the engine control system :)

Re: Microrusefi and 6 cylinders

Posted: Sun Nov 01, 2020 4:57 pm
by Gepro
Thank for your fast reply !
I already ordered a MicroRusEFI :D :D
I don't really understand why it's a 4 cylinder ECU, it can be good for V8 in batch ans wasted, no ?

In fact, I am more concern about ignition. Wasted spark is fine, but I don't want to stress the coils.

My engine is semi sequential injection and sequential COP with OEM ECU.
I actually use full sequential on my MS3X, the idle is just perfect, but I know it's useless at high RPM.

I don't find any base tune ? And the simulator doesn't look to support microrusefi.

I don't understand the "knock software", and I don't see knock input in the pinout.
I have an external knock module and don't see how to use it. (a lilknockmeter for information)

Sorry... I have a lot of questions :P :P

Thanks,

Re: Microrusefi and 6 cylinders

Posted: Sun Nov 01, 2020 5:21 pm
by AndreyB
The magic of electricity tells us that transistors in microRusEFI are rated to drive specific loads within specific limits. Driving 8 injectors in pairs means more heat on the transistors. Idling 8 injectors in pairs is easy, WOT with high injector duty cycle could be harder. At this point there are concerns if MRE would fail and when if used to drive 8 injectors in pairs.

I am confused between two many questions. Knock short answer is NO longer answer is https://github.com/rusefi/rusefi/wiki/knock-sensing

Re: Microrusefi and 6 cylinders

Posted: Sun Nov 01, 2020 5:52 pm
by Gepro
You are right, 2.2A is a little low for 2 injectors. But we are supposed to keep the injectors under 85% duty cycle.

My actual denso are 14Ohms, I will pay attention to the future ones.

Thanks,

Re: Microrusefi and 6 cylinders

Posted: Sun Nov 01, 2020 9:03 pm
by mck1117
Gepro wrote:
Sun Nov 01, 2020 5:52 pm
You are right, 2.2A is a little low for 2 injectors. But we are supposed to keep the injectors under 85% duty cycle.

My actual denso are 14Ohms, I will pay attention to the future ones.

Thanks,
The 2.2A limit means you could PROBABLY run 2 injectors per output, but I'm not confident enough in exactly all injectors being <1.1A, etc. I'd hate to "certify" that, then discover that some setup doesn't actually work, or when you turn off all your accessories and the battery voltage runs a little high, your injectors stop working.

Re: Microrusefi and 6 cylinders

Posted: Sun Nov 01, 2020 9:04 pm
by mck1117
Gepro wrote:
Sun Nov 01, 2020 4:57 pm
I don't understand the "knock software", and I don't see knock input in the pinout.
I have an external knock module and don't see how to use it. (a lilknockmeter for information)
microRusEfi doesn't yet have the hardware to do "software knock" without modifying the board and adding an external module. A future revision of the board may get it, but we're still proving out that the feature actually works.

Re: Microrusefi and 6 cylinders

Posted: Sun Nov 01, 2020 9:23 pm
by Gepro
Thanks for the answers ! It's fast and reliable.

I understand for "certification" I realise later that the high-Z injectors don't have the same impedance.

I will try to go full sequential and see what happens. A friend of mine as a picoscope, maybe I will try to see what happens to the differents injectors. (TLE8888 and VNLD5090)

Thanks,

Re: Microrusefi and 6 cylinders

Posted: Sun Jan 08, 2023 12:25 pm
by JoakimR
Gepro wrote:
Sun Nov 01, 2020 9:23 pm
Thanks for the answers ! It's fast and reliable.

I understand for "certification" I realise later that the high-Z injectors don't have the same impedance.

I will try to go full sequential and see what happens. A friend of mine as a picoscope, maybe I will try to see what happens to the differents injectors. (TLE8888 and VNLD5090)

Thanks,
Did you try the microrus on your 6 cylinder engine?