Setting up ignition

[PrecisionDyno]

Well, I am still reluctant to try to run the ducati as of yet.

Currently, I have set up on the bench two injection systems: 1. the mircrosquirt system with all the ducati injectors, sensors etc...
2. another stock ducati ecm/ harness injectors etc...

I have good steady crank signal and RPM from the microsquirt

what I am skeptical of right now is the ignition coil output on the microsqurit and whether or not it's firing when it's supposed to.

I have an occilloscope in front of me and I have it hooked onto the the output of the mircro squirt coil out.....I am comparing this signal to the output of the "stock" ducati ecm coil output....

and the two don't look the same and the microsquirt one doesn't behave the same way as the stocker.

Firstly, let me run through a couple things on ignition setup and tell me if im right.

On delay teeth, I have it set to 22, and I'll explain why:

On this ducati, it has only one VR sensor that runs off the cam gear that's driven by the crank. so it's half speed of the crank.... it's a 48 tooth wheel with 2 missing teeth

When the horizontal cylinder #1 is at TDC, the vr sensor is pointing at the 22nd tooth after the first tooth(after the second missing tooth)

So as soon as the vr sensor sees the first tooth after the second missing tooth it's then 22 teeth later and cyl #1 is at tdc on compression....

Then 270 degees later of crankshaft rotation the rear vertical cylinder #2 is at TDC on compression.

I have read the other posts by a few a guys trying to do a ducati setup, but somehow it got sidetracked with discussion on when they fire and who was right or not....what I have posted above is how they work for and 1997-up fuel injected 4valve motor. it is also the same for 1999-up 2valve fuel injected motors.

There are some obscure ducatis out there 95-96 916's that use two vr sensors. one on the cam and one on the crank but I doubt you'll ever see those.
The carb'd 2Valve ducatis use two sensors on the crankshaft phased 90 degrees from one another and these years range from (i think) 92-97

1. What I am trying to figure out is am I calculating my delay teeth right?
2. And how do I determine Skip teeth?
3. what offest advance? ( i have this set to -310) 40+270=310....?
4. Should my prediction settings be "last interval" or "alpha beta gamma"?

I feel as thuogh i am very close to making the move to actually run the bike, but I want to get it dialed in on the bench, as you well know it's much easier and saves the life of a starter motor.

[SQLGUY]

SInce you're dealing with an odd angle system and a cam sensor, you will want your skip teeth to be 0.

Dual spark should be set for Single Cam Wheel, and offset advance will be the negative number to apply between firing #1 and #2. Sounds like it should be -225 degrees of cam rotation.

Once you have this on the bike, a timing light will make it easy to see whether you got it right, or what items need to be changed. Last interval should be fine for the prediction... you have plenty of teeth to get some fairly high resolution.

By the way, just so we're not overlooking anything, are those two missing teeth next to each other? If not, things get a bit trickier.

Cheers,
Paul

[sportage4x4]

the two teeth are consecutive.

be mindful that the cam gear rotates opposite of the crank direction.

the vertical cylinder fires first, 30 teeth later the horizontal cylinder fires. or yeah i guess you could consider the horizontal firing first, and 18 teeth later the vertical fires

[PrecisionDyno]

The horizontal front cylinder is considered #1, so that's what im useing as my base.

The front cylinder has always been considered #1 by ducati and that's what they base all their ecm mapping off of, stock ducati ecm's have one main fuel map, thats the mapping for both cylinders, then they have a secondary fuel map that is an adder/subtracter from the main fuel map and this map is for the rear cylinder.(same for spark tables as well)

I am quite aware that the cam gear turns opposite the crank. I have built a few ducatis in my day. www.foxperformanceengines.com

[sportage4x4]

Ahh, you do some excellent crank work!

[sportage4x4]

which duc engine is this for? i'm going to try to squirt my first 4v sometime this week, or next. its a shallow sump 999 in a 916 chassis.

do you have any trigger info wrt to the 1098 engines? is it still the same 48-2?

the P7/P8 ecu'd desmoquattro's use the twin trigger setup. 851/888/916 early/916SP/996SPS

[PrecisionDyno]

if you want to compare notes, you can call me at (719) 570-9595 or email me at benfox@foxperformanceengines.com

I feel this project has a lot of potential, as any 1.6 ecm or older p7/p8 computers are turds to say the least. and burning chips for them is ridiculous and archaic in my opinion.

im working on a plug an play harness for the MS

I have a "male" version of the big 35 pin plug that will plug directly into the ducati ECM, so no cutting and splicing on the ducati harness side.

basically I wired my male connector to the MS harness and then plug it into the ducati's stock harness and it's good to go.

I am pretty sure I can get more of thee plugs...i'll keep you posted.

I just need to get somethig reliable on the bench before going to a bike, I can see how hard it would be to try and sort ignition set problems on an actual bike, and you could easily ruin the starter sprag in the ducati if your timing is not firing right, so any info I learn i will share with you guys.


btw I am 90% sure the 1098 has the same 48-2 trigge wheel, ducati rarely changes things, and im pretty sure there's only one ignition pickup on the new 1098.

[Paul_H]

If I am understanding your trigger wheel setup correctly, then when the first tooth after the missing teeth alligns with the sensor pole, the horizontal #1 cylinder piston would be at approx 35 degrees ATDC overlap. I would think that if you then delayed this tach event by say 23 teeth, it would then happen approx 15 - 20 degrees ATDC compression for this cylinder. This would satisfy the dual spark requirement for a negative offset and allow you to configure about -20 degree trigger offset.

I think if you skip 24 teeth (360 degrees of crankshaft rotation) to create the tach event for the vertical cylinder, logic says that you will need to apply a 90 degree offset to allow for the odd firing angle given that the vertical cylinder is at TDC compression 270 degrees after the horizontal cylinder fires.

After having said all of that, applying that offset logic to my engine did not work. Even though my engine is a mid 70's bevel twin with a 24-1 tooth crank wheel configuration, the principles are the same. I found that with the above thinking applied to my setup the vertical #1 cylinder was timed correctly and would run but the horizontal cylinder would only misfire. Thankfully the vertical cylinder would continue to run which allowed me to setup the timing light on the misfiring cylinder. This quite clearly showed me that the timing was out by 180 degrees. I did not understand this but altered the odd angle offset from 90 to 270 degrees anyway and the rest is history. The engine is now timed correctly, runs sweetly and the bike is back on the road being ridden and enjoyed.

This is only an account of my experiences and I must admit that I still can't get my head around what has happened here but I hope that out of the above ramblings, you can find something that is of use to you.

[sportage4x4]

the only real problem i for see is the ducati's propensity to nearly stop dead while cranking. no doubt light cranks, light flywheels, higher compression and the racer's choice of the smallest battery around only exaggerate the issue. granted, the newer 4v's are better, but still, some of those long crank 'pauses' could be confused for missing teeth.

i have a cam layshaft gear mounted to my test bench, and it works just fine on the bench. however, i can not easily simulate the very rhythmic cranking speeds.

have you considered testing with a MS2 daughter card in, say, a V3 mainboard? would make probing and testing easier. also if something fails it is repairable. once its working transfering over to a microsquirt shouldnt be a problem.

[Paul_H]

OK, thinking more about your configuration by comparing it to mine has helped me nut a few things out. Firstly I am using -25.0 degrees trigger offset because that is how I mechanically set it for the tach to occur so I would not have to use any delay teeth. But in your case, because you cannot alter the position of the trigger wheel on the shaft ( assuming it is keyed) you will need to use whatever number of delay teeth that it takes to shift the tach declaration from when it physically occurs to when you want it to happen (preferably about 15 - 20 degrees ATDC).

Secondly, because I am using an M - N crank wheel only setup I have to use a number of skip teeth that ensures that an ignition event occurs every 180 degrees ( in this case 12 teeth because I am using a 24 tooth crank wheel). The tach event that occurs at this point is for cylinder #2 and an offset is applied to allow for the odd firing angle (cylinder #2 fires 270 degrees after cylinder #1).
In my case the offset should be -90 degrees (referencing where the tach occurs to where TDC for cylinder #2 is) but this does not work for me because MT does not seem to allow or recognise a negative offset resulting in no spark for cylinder #2. Fortunately 270 degrees achieves the same result by making the same reference as -90 does. In your case because you are using an M - N cam wheel you will create the tach event for cylinder #2 by skipping 24 teeth which means that this tach will occur 360 degrees after the tach for cylinder #1. As mentioned above, because cylinder #2 fires 270 degrees after cylinder #1, the second tach will have to be referenced to TDC for cylinder #2 and this means applying a 90 degree offset. In this case because it is a positive offset MT will allow you to apply it and it should work.

This is long winded and you are probably thinking that I am only preaching to the converted but I hope that it is of some help anyway.