Cam-aware siamese code, now with full sequential staged injection
Turbo Mini Forums

At last, I have a first version of the siamese code which can take advantage of a cam sensor and adjust the pulse width and injection timing of the inner cylinders. I still haven't added the 2 extra injector drivers so staged injection is not an option for full sequential yet. But that shouldn't take too long to include now that the rest is there but I'm getting extremely close to filling up the CPU memory with the new code so that may become an issue.

This code is based on the latest beta MS2/extra code with all the bells and whistles of this version. The file attached contains the code (s19 file) and the ini file for Megatune. The siamese options are in the advanced menu under the sequential injection option. Hopefully the options there are self-explanatory but if not let me know and I'll explain.

To use the full sequential, you'll need a cam sensor (of course) and you'll need to tell the MS2 using the appropriate options in the "Tach input/Ignition settings" section and "Trigger Wheel Settings" section of the Basic setup menu. I'll put up pictures for the correct setup later but for a 36-1 wheel and cam sensor, you should use Toothed wheel and Dual wheel with missing tooth, Crank wheel and every rotation of Cam.

The semi-sequential injection is still an option so can be a good first step to use the code. When going to full sequential, to have the same injection timing as semi-sequential you need to select Dual values for the Number of timing values (in the Sequential Injection window) and set the injection timing 2 to a value 180 degrees more than timing 1. To set different pulse widths for the inner and outer cylinders, you need to use the dual table mode ("Basic setup" menu, "General, lags" option, "Dual Table Use"). Then Fuel VE table 1 is used for the outer cylinders and Fuel VE table 2 is used for the inner cylinders.

The code hasn't been thoroughly tested but on the bench it seems to do what it should do in terms of pulse width and timing (correct for start-of-pulse, mid-pulse, end-of-pulse timing). I have not really tested what happens when the inner and outer pulses overlap but there is something in the code to handle it theoretically. So it would be safer for now to keep some margin between the 2 pulses (meaning don't use a single value for the sequential timing).

By the way, all the default values are the same as the original MS2/extra code (except for the number of cylinders and the sequential injection options) so there are very likely a lot of inappropriate values and will need to be examined.

Enjoy!

Jean

Attachments:

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Edited by jbelanger on 21st Feb, 2009.

http://www.jbperf.com/

Excerrrlent.



I'm off to Paris again next week, but I can play with it when I get back.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I look forward to see your results.

Once you have (or somebody else has) some workable setup, I will be able to use those as the default values in the code. Even though all setups will be different and require tuning it will be a better starting point than what is currently there.

Jean

http://www.jbperf.com/

Edited by sturgeo on 15th Feb, 2009.

You leave the car at the back of the barn till I get back.

Jean, I presume that I need to move the cam sensor input to JS10 in the first instance?

Will we need the Jimstim or shall we just download the code, set up a new .msq and see if it will run?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Yes you need the cam sensor on JS10.

You could try to setup a new msq and see if it will run but it wouldn't be a bad idea to get the feel for the code on a JimStim. There are so many differences between what you used and the new code that it will need some getting use to. If you just need to assemble the JimStim and not have to order one then that's the thing to do.

And sturgeo will have time to do this while you're away (unless you wanted to do it). :)

Jean

http://www.jbperf.com/

if you want i can post my built jim stim up.

Excellent Jean,

This is just the incentive I need to get on with things (and the sun is out today as well !!!)

I've loaded the two files and I think I must have done it right as I now get "Sequential Siamese" on the dropdown menu and it lets me burn it to the CPU and retrieves it OK.....

I don't have a JimStim (another mistake I made early on) so I'm probably going to improvise something for "testing" (maybe even a mechanical device, motor, trigger wheel and actual VR sensor), but one question first...

Does your JimStim have the ability to replicate the cam pulse as well as the 36-1 pulse ???

Schrödinger's cat - so which one am I ???

Yes the JimStim has the cam signal as well as the crank signal. The phasing of the 2 may not be the same as what you have on your engine but that doesn't make a real difference in the case of a 36-1 since the code only uses the cam sensor to reset the tooth count on the following missing tooth.

If you can simulate your setup with a motor, a wheel and a sensor then you may not need a JimStim. The advantage of the mechanical setup is that the signal is going to be closer to the real signal which may make for less fidlling once you install the ECU in the car.

Jean

http://www.jbperf.com/

One more thing about the mechanical setup. It's going to be much tougher to simulate a cam signal since you're going to need some sort of gearing to get the half speed signal unless you use a 72-2 wheel for the first sensor and a separate tooth for the second sensor. The advantage of this is that you get a speed doubling effect and the motor doesn't have to turn as fast to simulate high revs.

Jean

http://www.jbperf.com/

Thanks Jean....

Was there ever an optimum phasing agreed between crank and cam ???

I remember you asking the question about the MPI phasing but I don't remember it ever being resolved....

Although it's only a reset, is there a preferred point for it ???

Rod.

BTW, all your work is really appreciated by the likes of me :)

Schrödinger's cat - so which one am I ???

Well, I bought the Jimstim in kit form a couple of months ago in readiness for this. Sturgeo is going to build it up this week.

Rod, I'm sure that Mini13's offer would be available to yourself.

Not sure when we will actually get round to testing the code on the car, but it will not be long as everything is ready.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

For the 36-1 wheel, the phasing is much less critical. The only thing you want is the have the cam tooth away from the crank missing tooth. Something like 30 to 90 degrees before the missing tooth will work fine.

As for my work, I'm glad it's appreciated and glad to see people involved in this. And I'll have to take a trip to the UK and get a ride in one or all of the siamese code running Minis especially once they have their turbo running.

Jean

http://www.jbperf.com/

Schrödinger's cat - so which one am I ???

Yep, can borrow mine no probs Rod,

Cheers Joe,

You have PM...

Schrödinger's cat - so which one am I ???

I just realised something about the code. The injector driver 1 is correctly timed for TDC of cylinder 1 but it's timed for the ignition event not the intake event.

So that means that the code I posted will require the use of injector driver 1 in the 3/4 intake and injector driver 2 in the 1/2 intake. I'll correct this for the next release.

Semi-sequential is fine with both drivers firing at the same time if not using staged injection or, if using staged injection, injector driver 1 is used for both primary injectors and driver 2 is used for both secondary injectors.

Jean

http://www.jbperf.com/

Jean,

In light of the above, should the cam sensor be set 30-90 degrees before the missing tooth, when the missing tooth is on No.1's compression stroke or on No.4's ???

Or is it switchable in Megatune (I haven't looked that closely yet and am using daylight hours to put second (test) engine together and weld injection manifold.....)

Rod.

Schrödinger's cat - so which one am I ???

All references in Megatune are for ignition timing. So that means that the tooth 1 angle will be in reference to TDC of cylinder 1 on compression/ignition stroke which is what you should use for the cam sensor reference.

Like I said, I will correct my injector phasing in the next release but in the meanwhile it's just a question of switching the injector connectors from one side to the other. It would also be possible to set the timing in Megatune 360 degrees out. So you could do which ever you find easier to correct.

I expect to have the new release very shortly and it will have the 4-driver feature for full sequential staged injection.

Jean

http://www.jbperf.com/

Thanks Jean.

Sorry if my question came across wrong, I wasn't being critical of the 1/2 to 3/4 injector mis-match, I just wanted to be sure I was putting the phase sensor in the right place.

Done - fitted on 60 degrees before missing tooth with No.1 compress/ignition.

Considering the way forward with four drivers, is this your correct board ???

Peak&Hold Injector Driver Board V1.1B

If so, I'll order mine in anticipation....:)

EDIT, link...
http://www.jbperf.com/p&h_board/index.html#V1.1A

Edited by Rod S on 17th Feb, 2009.

Schrödinger's cat - so which one am I ???

I didn't take this as a critic at all I was just stating it another way.

And yes, that's the board. But it will be needed only if you have low impedance injectors. It will work with high impedance injectors but it's more expense than what's needed in that case.

Jean

http://www.jbperf.com/

The 4-driver code is not yet ready but I thought I'd give you an idea of the modification needed on the MS2 card. The picture below shows a close-up of the MS2 card and the NAND chip on it. What I did is to solder a small jumper between pin 1 of the NAND chip and pin 4 of the card and another jumper between the via just besides pin 4 of the NAND chip (which is connected to pin 4 of the chip). The second jumper is more difficult to see because the wire is completely stripped due to how short it is. The wire is a 30-gauge wire wrap wire (single strand).



This is not a difficult thing to perform but will work better with a fine solder iron tip and fine solder (I used 0.015" solder). And it might actually be easier to solder the wire directly to pin 4 of the NAND chip instead of using the via.

By the way, this requires that the clock circuit (crystal and other components) on the V3 board not be installed (only required for MS1). Pin 4 of the MS2 card connects to R22 (injector driver 3) and pin 5 of the MS2 card connects to R23 (injector driver 4).

Jean

http://www.jbperf.com/

Schrödinger's cat - so which one am I ???

Yes you will need to add injector drivers in any case but you could just use something like 4 of these. Bolt them to the heatsink (since most of what is there would no longer be needed), add 8 resistors to the proto area and wire them in the correct way (which I'll detail later).

But like I said, the p&h board is definitely an option because it will work perfectly fine with either low or high impedance injectors. I'm actually driving the JimStim LEDs now in my bench testing so they will drive whatever is connected to them.

Jean

Edited by jbelanger on 18th Feb, 2009.

http://www.jbperf.com/

Thanks Jean,

At least I'm not going mad....

I'll probably stick with the low z injectors (I have them and am used to them) and invest in one of your "Peak&Hold Injector Driver Board V1.1B" but I'll wait a while before ordering and see how things go with the current (non-staged) version.

Again, all your work on this really is appreciated... I finished building the "test" engine today and will start welding all my injection manifold bits tommorow......

Schrödinger's cat - so which one am I ???