Staged Injection Manual?

[OB6D]

Folks,

I'd like to use staged injection with dual tables on the MicroSquirt with MS2-extra code. I have 4 injectors on my two cylinder and they're reasonably sized. So i'd like to run on 1 pair till say 6000 RPM, where the other pair would kick in to assist.
The pulsewidth at idle using them all would have to be around 1ms which is nowhere the bandwith i've seen suggested in some manual somewhere.

Speaking of manual, it's probably me, but i can't find a proper description as to how to set this up anywhere. Now if someone would be so kind to point me to where this info is, i'd be very thankful and i'll do my reading and take it from there.

I've attached a picture of the screen i want to set up. Had a go at this already and i expected the second tables would become active if i would enable this. But they didn't. They come into view when enabling dual tables though, so maybe it's a combination of things that is needed?

Thanks

[Eagle7]

On the "Standard Injection" dialog, set "Injector Staging" to Simultaneous. On the "Injector Characteristics" dialog, set "Specific bank 2 setting" to Off. On the "Staged Injecting" dialog, set it up for how/when you want the secondary injectors to turn on/turn off. When they do turn on, the first table is still used, but the required fuel is now split between the primary and seconday injectors, so the pulse widths will be equal (for equal injector sizes), and will be half of what it would have been for just the primary injectors. I don't know if/how it's possible to use dual tables.

[jsmcortina]

Staging is designed so you keep one table and the ECU automatically brings in the second set of injectors under the conditions you programmed.

James

[OB6D]

Thanks Eagle7, i'm gonna try that. I thought there would be one table for bank one, one for bank 2.

I understand what it's for James, just don't understand what i'm supposed to fill in in the dialog, that's why i posted a screenshot of it.

I'd want to start with, try and set it so the second bank comes in at 6000 rpm and TP > 20.

So i fill in RPM, secondary TP and the logic i bet will be AND. Injector size is already given, but i fill this in again. ok. The transition is, i bet, how fast it switches. Now i'm guessing you can give in somehow the point where it switches back, so it won't get too nervous around the kick in spot. But i don't see how. Primary reduction i guess is how fast the first bank scales down to half the PW. The secondary enrichment is maybe some sorta hickup prevention.

But what i really don't understand is what these 2 mean:
Pri/Sec staging threshold(units)
Pri/Sec staging hysteresis(units)

So on purpose i fill in something stupid, 'n then it tells me it can be 25500 at most, which leads me to believe there should be an rpm value in there?
Eehhh, so the threshold i guess is then the kick in point in rpm's and the hysteresis the lag with which it stops if rpm drops under the threshold? So 6000 and 1000 as values would mean, start at 6000, stop when dropping under 5000? Right? Then why fill this in seperately for primary and secondary?

Or do i fill in a bandwith for which a bank is active in rpm?

I don't get those two, could someone please shed a little bit of light on those?

[Eagle7]

I believe the terms "primary" and "secondary" are used for two different things in this dialog. The "threshold/hysteresis" entries refer to the first parameter and the second parameter. I think you had it figured out - that parameter has to rise above the threshold before the parameter is active, and it remains active until it drops below (threshold - hysteresis). The parameters can be combined so that staging is active only when they or both active (AND), or when either one is active (OR).

The other entries control how the transition is managed. In some engines the primary injectors may be in a very different location than the secondary injectors (such as my RX-7). In that case, if the transition was instaneous, there would be a lean spike when staging engages, because the fuel from the secondary injectors needs to travel further before it reaches the combustion chamber.

I believe "primary reduction delay" keeps the primary injector at its non-staged pulse width for this delay period while the secondary injector is ramping towards the staged pulse width.

I'm guessing that "secondary enrichment" adds to the secondary pulse width during the transition. In any case, you should be able to experiment and see the effects that various settings have by examining the log from a run.

[OB6D]

I believe the terms "primary" and "secondary" are used for two different things in this dialog. The "threshold/hysteresis" entries refer to the first parameter and the second parameter. I think you had it figured out - that parameter has to rise above the threshold before the parameter is active, and it remains active until it drops below (threshold - hysteresis). The parameters can be combined so that staging is active only when they or both active (AND), or when either one is active (OR).

The other entries control how the transition is managed. In some engines the primary injectors may be in a very different location than the secondary injectors (such as my RX-7). In that case, if the transition was instaneous, there would be a lean spike when staging engages, because the fuel from the secondary injectors needs to travel further before it reaches the combustion chamber.

I believe "primary reduction delay" keeps the primary injector at its non-staged pulse width for this delay period while the secondary injector is ramping towards the staged pulse width.

I'm guessing that "secondary enrichment" adds to the secondary pulse width during the transition. In any case, you should be able to experiment and see the effects that various settings have by examining the log from a run.

Thanks Eagle7,

Threshold - hysteresis = dead band then i suppose. Then it must be one for activation, the other for deactivation...
Say the switchpoint is 6000 RPM then it must go over 7000 before it can be switched off again, and then under 5000 before it can be reactivated. Nah that won't work, there'll come a time when some requirement isn't met and they won't kick in or stop and you'll go lean or rich...

Somewhere on some other forum i've read, that those boxes take values of 0 to 255 that convert to rpm. Is this so, that's not a unit is it. What goes in there?

I can't get up to those rpm values at the moment cuz of some issue, so i figured i'd just study this in advance, cuz i know i want to use it. Being well prepared and informed usualy works better then taking wild guesses.

[dontz125]

You're trying too hard - you had it right the first time!

For the numbers you're suggesting (6000 threshold and 1000 hysteresis), staging will come on at 6000, and stay on until the engine drops below 5000, and then stay off until you cross 6000 again.

[molak]

Is there a way to add the secondaries injectors without closing the primaries ?

I'm going to install a MSII on a car that has ITBS + Turbo, so running Hybrid alpha-N is almost mandatory.

The car runs 100% methanol and high boost so a need a lot of injector flow. I'll use 96 lbs/h on the primaries and 150lbs/h on the secondaries. if i close the 96lbs/h injectors, 150lbs/h wont be enough. So standard stagging is not an option.
-Dual map can't be used with hybrid alpha-N
-Running the together will be really difficult to make the car idle,start and off boost tuning will be dificult.. Plus, due to the lack of space i have to fit 1 set of injector before the ITBS and the other after.

[Eagle7]

The primaries don't close completely. The required fuel is split between the primaries and the secondaries according to their rating. When staging activates, your secondaries would supply 150 / (96+150) and the primaries would supply 96 / (96+150).

[molak]

The primaries don't close completely. The required fuel is split between the primaries and the secondaries according to their rating. When staging activates, your secondaries would supply 150 / (96+150) and the primaries would supply 96 / (96+150).

thanks for the reply, I thought that fuel was completely switched to the secondaries...

[mike_robert]

Eagle7 is correct -the secondary injectors' capabilities are added to the primaries. The code calcs the new pulse widths based on the flow capability of each set as eagle7 relates.