Sequential code for 4-cylinder engines

[md95]

md95:

Maybe I will give it a try then. I have a 60-2 trigger-wheel. Cyl 1 is at TDC 78 degres after the first tooth. I have read all the semi-sequential treads and as I understand it MS divides 720 crank degrees into 8, and this is what you can select in the injector sequence. Am I right? I am a little bit confused how this really works with my trigger wheel. Since it is only semi sequential I do not need a second trigger (Cam-trigger) right?

Now I use 1 squirt simultaneous and I saw Ken write that then I must wire injector 1+3 together on injector 1 (Db pin 32/33) and injector 2+4 on injector 2 (Db pin 34/35).

As I said I was considering trying this but the lack of documentation frighten me a bit. The big question was whether it would work with my triggerwheel and without a second trigger (I know I need second trigger for full sequential).

Thanks
vegard

I'm not 100%, but i dont think you need a 2nd trigger wheel(actually you dont, because even on my wheel, its only using the main wheel, not the 2nd trigger) Assuming your firing order is 1-3-4-2, you would use tooth 1, bank 1 on cylinders 1&3, which puts fuel injection on cylinder 1 at 78 degrees BTDC, which is perfect. Add 180 degrees to 78, and this is when cylinder 3 gets fuel, which is 258 degrees BTDC, pretty much identical to my setup. Now, from tooth 1 on your wheel, take the tooth that is 180 degrees from that. This is the tooth to fire bank 2, which is injectors 2&4. This puts injection on cylinder 4 at the same 78 degrees BTDC, and 258 degrees BTDC for cylinder 2. Since you have a 60-2 wheel, i'm not sure exactly how that translates into tooth numbers for semi-seq, but your settings might be 1, 5. Half of a wheel would put the 2nd tooth at 4 or 5. Either way, the new way of semi-seq code only uses one tooth number setting anyway, and the code automatically chooses the right tooth that is the next tooth 180 degrees apart on the wheel. So you would only input the one tooth number, the code does the rest. You could try 1 first, then try 4 or 5. See which one runs better. Set the constants for 2 squirt alternating. My guess is that you will want to input tooth 5 first. When i was doing initial testing, you had to input both teeth, which for me was 3,7. With the newer semi-code where you only input one tooth, i had to use 7, not 3, for it to run right..not sure why but thats how it worked, so this is why i say start with tooth 5. This is providing your firing order is 1-3-4-2, and injector banks wired 1&3, and 2&4.

[racingmini_mtl]

Any updates on this? Right now I am batch firing my injectors, but I plane to go semi or full sequential. I have a 2,0 l with 4 630 cc injectors. My idle PW is 1,4xx ms right now. If the sequential code is not that fare of I will wait for it and not go semi. I will have to do some more wiring before that as well to get my second trigger working and do some more injector wiring.

Thanks
Vegard

There has been some progress but I haven't spent as much time on this as I wanted. I just need a few more days where I concentrate on this and I should have something functional. However, this will be very much alpha code.

The code will allow timed injection using the standard 2 injector drivers or using 4 injector channels with off-board drivers. This last option will require some hardware modifications to the MS2 daughterboard (2 wire jumpers). The code will allow semi-sequential for 1 to 8 cylinders (except 5 and 7 cylinders) and full sequential for 1 to 4 cylinders. Full sequential will require a cam signal and that the ignition is configured for COPs. Per-injector channel VE trim will be possible and injection timing will be set with either a single angle value or using a 6x6 table. Staged injection will be possible with engine with 1, 2, or 4 cylinders but will only allow semi-sequential injection for 4 cylinders due to the limited number of injector channels. Full sequential injection will, of course, have a single squirt per cycle while semi-sequential will have one squirt per rev.

For the small crowd running the classic Mini (or using a similar engine), the code will allow port injection of the siamese-port engine. The code will allow for semi and full sequential with or without staging. A few additional inputs will be available for this configuration but I'll give the details in a separate post when the code is ready.

Jean

[racingmini_mtl]

Full sequential injection will, of course, have a single squirt per cycle while semi-sequential will have one squirt per rev.

What I meant here is that it's going to 1 squirt per injector per cycle for sequential and 1 squirt per injector channel per rev (or 2 per cycle) for semi-sequential.

[mops]

ideally we want programmable end injection angle, where injection always ends in a particular valve position (just before it is fully closed, results vary with particular point), therefore start of injection is always different, depending on the PW....

[racingmini_mtl]

ideally we want programmable end injection angle, where injection always ends in a particular valve position (just before it is fully closed, results vary with particular point), therefore start of injection is always different, depending on the PW....

And you'll be able to have that with the code I'm writing. Actually you'll be able to chose if the timing reference is the end-of-pulse (what you want and what most user will want), start-of-pulse (which will probably be of little use but is easy to do), and mid-pulse (which might be interesting for the siamese-port engines with a small injection window and where the middle of the effective pulse width is used as the angle reference).

And with the use of a timing table instead of a single value, you can take into account the difference in travel time for the fuel to go from the injector to the intake valve with different loads and RPMs. So, if at 3000RPMs the fuel doesn't travel twice as fast as at 1500RPMs then you can either advance or retard the injection timing so that the last drop of fuel gets to the intake valve always at the same time in the engine cycle. Hopefully a 6x6 table will be sufficient for that because that all the space I have for it at the moment.

Jean

[rb26dett]

awesome work should be pretty sweet.

[FiatFreak]

Any further updates on the sequential code? I've been following the latest beta releases, but didn't notice mention of this code ever getting in there.

Thanks,
Patrick

[hassmaschine]

I think semi-sequential is at least in there - I've been getting ready to update my setup to use it. but stupid 70 hr work weeks are getting in the way. :p