Sequential/semi-sequential code

[racingmini_mtl]

Yes the timing is intentionally crank degrees and you can actually cover the entire cycle because you can go from -360 to 360 (not just 0-360). And the the timing is with respect to what is TDC as defined by what you enter as your wheel configuration. But I'm glad you confirmed with your setup what my own testing showed me.

I agree that it would be interesting in your case to be able to adjust the MAP reading point to precisely where you need it. However, it might not be as useful as I first thought when you talked about it. Bruce posted something today (http://www.msefi.com/viewtopic.php?f=38&t=33901)that shows that on multi-cylinders with a single MAP sensor, the signal is not well behaved. So having a user-defined sampling point might not show as much of a gain as it would for a single cylinder engine. Which might push back the priority on implementing that. I still want to keep that as a possibility but a bit lower down the list of things to do.

Jean

[myk777]

Jean,

Thanks for the info on the ability to go -360 to +360, I wasn't aware negative numbers were allowed. In fact I just tried it in TS and it does work, however it is a bit quirky to get a "-" sign into the field as TS thinks you want to reduce the value when you push the "-" key, I had to set the value to zero then push "-" to get the negative sign to show up then you can highlight just the number and edit it you what you need. Maybe need to notify Phil of this one.

With regards to the map signal, I just read Bruce's post and although I agree that the signal is not well behave when they are all Tee'd together, I still think they could get great results by just using a single sensor on any one of the individual ITB's and try to do what I am, I don't see the need to sample all the cylinders if they are behaving the same (which looks to be the case from his graph of the individual sensors), I'll put a post over there asking the question but I think this would be just as valueable no matter how many cylinder the engine has and has a real possibility to make SD and ITB's work together (of course I'm a bit biased )

Mike

[Keithg]

Jean,

An odd request. Is there any way to 'fake it' for MT? I mean, once the settings are set for sequential in TS, can I roll a faked up MT ini file so that I can tune as normal with MT? I loaded TS on my small, old tuning laptop and it is too large and heavy for my P3/374mb tuning laptop. With TS loaded up on the bench with the stim, the laptop fan went on high and ran continuously. That, and I have reservations about its stability. I drove in on 2.10m beta and had 2 issues on my drive in. 1) BSOD - this is on my very stable work computer with 2g ram and a Core 2 duo (I have not seen a BSOD for years) 2) then I got an error where all the gages went wacky.

Keith

[racingmini_mtl]

Keith,

If you were to comment out all the table editing for the trim tables in the ini, you could use MT. That would not allow you to use the trim tables (of course) but I don't think this will be something you'll need to start with.

Jean

[SantosRacing]

Wow that just awesome, I've got a couple of MS2e running your peak and hold injector driver board so making this change would be quick, if you can post a s19 for a 420a or a 36-2+2 (newer dodge neon 03+) I can test them and report result right away as both car are running and licensed to be on the road.

[racingmini_mtl]

There seems to be an issue with the 420a code when using the cam sensor which is also in the base MS2/extra code. I'll do a test with the 36-2+2 and I'll get back to you. I still have your email and I'll send you the code.

In any case, the plan is to have the sequential code updated with the latest MS2/extra beta upgrades and having all the wheel modes available in the same s19. This should happen in the near future.

Jean

[Dennis930]

Jean,

Can you explain how the semi-sequencial staged injection works for a six cylinder with a cam sensor and four injection drivers?

Thanks,

Dennis

[racingmini_mtl]

Dennis,

It will actually use only 3 injector channels (firing 2 injectors each) and will work in a manner very similar to wasted spark. So for this configuration, you don't need the cam sensor unless you also do COPs which do require the cam sensor. But if you have a cam sensor and specify additional injector drivers, the code will automatically configure to use 3 injector channels (as it will if you do not have the cam sensor).

It will fire each injector channel on each rev so each cylinder will actually have 2 squirts per cycle. And the injection pulses will be timed with respect to TDC: on one rev it will be timed with respect to the compression/combustion TDC and on the other rev it will be with respect to the exhaust/intake TDC. This is exactly like wasted spark ignition. Also like ignition, positive timing numbers are BTDC degrees and negative numbers are ATDC. Of course, you have to pair the cylinders correctly but again this is like wasted spark: you pair the cylinders that are 360 degrees apart.

If you use high impedance injectors then you can use one driver per channel and drive 2 injectors per driver. With low impedance, if you use peak&hold drivers you need one driver per injector so you'll need 6 drivers and each channel will control 2 drivers.

Jean

[Dennis930]

Jean,

Thanks for clearing this up. The table in your original post showed 4 injector drivers with 3 squirts per 720 degrees. I could not figure out how 4 injector drivers could be used on a 6 cylinder.

Dennis

[racingmini_mtl]

Dennis,

I'm sorry I didn't get that. It is actually correct if you set it up for staged injection (as indicated). There's so many different configurations in that table that I didn't realize you were talking about that one.

So if you want to use staged injection with the additional injectors, you will have to have to have a cam sensor and group them in 2 groups of 3 cylinders 240 degrees apart with the primary injectors on injector channels 1 and 2 and the secondary injectors on injector channels 3 and 4. And you will have 3 squirts per channels every 240 degrees (and 120 degrees between the 2 banks). So you basically have staged banked injection.

I must say that the table presents a lot of options and the code will do them all but some (most?) of them are of little interest. However, they all offer you a choice to move the injection point around in a predictable and consistent manner and have the possibility to have an independent fuel trim on each injector channel.

Jean

[automat]

ok if I get that right, I can use a 4th injector in staging on my 3 cylinder engine? that's pretty cool I'd love to try that code but i'm missing a few components

[racingmini_mtl]

ok if I get that right, I can use a 4th injector in staging on my 3 cylinder engine? that's pretty cool I'd love to try that code but i'm missing a few components

Unfortunately, no.

With a 3 cylinder, with staging you can only use 2 injector channels (primary and secondary) with 3 squirts. You can't have 4 injectors because it would be 3 injectors with 1 squirts and 1 injector with 3 squirts and the code doesn't do that. With no staging, you either have the choice of 1 injector channel with 3 squirts or 3 injector channels and 1 squirt.

Jean

[Keithg]

Keith,

If you were to comment out all the table editing for the trim tables in the ini, you could use MT. That would not allow you to use the trim tables (of course) but I don't think this will be something you'll need to start with.

Jean

Jean,

is this in the constants definition section, nthe menu section or the table editor section or all of them?

Keith

[racingmini_mtl]

Actually, i have done it and attached it here. You can use the attached ini with Megatune or if you go to TunerStudio, you can just change the line

Code: Select all

#unset TRIMTABLES

to

Code: Select all

#set TRIMTABLES

and you will have access to the trim tables.

Jean

[RickRST]

jean, do the extra 2 outputs for injectors take the place of any of the other out/in options?

Rick

[racingmini_mtl]

Rick,

No. The 2 standard injector driver use 4 CPU pins. The hardware modifications and the code allow the 4 pins to be used for 4 injector drivers (instead of 2) but you lose the PWM capability. All the other I/O features can still be used as before.

Jean

[racingmini_mtl]

There is now a new version of the code linked here: http://www.msextra.com/viewtopic.php?f=91&t=30698. The code is now officially part of MS2/Extra.

Jean

[Dennis930]

racingmini_mtl wrote:
So if you want to use staged injection with the additional injectors, you will have to have to have a cam sensor and group them in 2 groups of 3 cylinders 240 degrees apart with the primary injectors on injector channels 1 and 2 and the secondary injectors on injector channels 3 and 4. And you will have 3 squirts per channels every 240 degrees (and 120 degrees between the 2 banks). So you basically have staged banked injection.

Jean,

So if I understand this correctly, for a 1-6-2-4-3-5 firing order, I would group cylinders 1,2,3 as primary and 6,4, 5 as secondary, then connect the primary injectors to injector outputs 1 & 2 and the secondary injectors to injector outputs 3 & 4. I assume the software fires the injector outputs in the following order: 1-3-2-4 at 120* intervals. Is this correct?

Dennis

[racingmini_mtl]

Dennis,

Just to be clear, with staged injection you have 2 injectors per cylinder. The primary injectors are used at low load/RPM and the secondary injectors are used at high load/RPM together with the primary injectors. This is done when you have a very powerful street engine (usually forced induction or very high RPM engine) which requires very big injectors to make the max power but where you want small injectors to be able to have a decent idle and streetability.

Which means, you would group 1,2,3 and 6,4,5 as you mention but injector channel 1 is primary for 1,2,3, injector channel 2 is primary for 6,4,5, injector channel 3 is secondary for 1,2,3, and injector channel 4 is secondary for 6,4,5. At low load/RPM, the primary injector channels are fired 1,2,1,2,... every 120 degrees. At high low load/RPM, both the primary and secondary injector channels are fired (1+3),(2+4),(1+3),(2+4),... every 120 degrees where (1+3) is the pair of primary and secondary channel fired at the same time and similarly for (2+4).

Jean

[Keithg]

Jean,

I could not wait for the board and soldered up 4 outputs on a piece of perf board. It works on the stim. Now, If I select 'Sequential/semi' and select 'additional drivers', how does the number of squirts play into it? I have not double checked everything on the stim, yet. and want to know before I put it in the car.I want it 4 squirts in 720 degrees, 1 per each injector. It appears I need to set it to 2 alternating or 1 simultaneous to get what I want.

Keith