998 - 1038 mapped

[chris steedman]

Today my fourth , 5th or whatever 1038 was mapped. The bike had a long spec list .

Bursi intake stacks , 749R cams , big valved heads , pistol 1038 kit , large airbox and 60mm pipes. I blueprinted ,balanced the engine and converted the heads many months ago and today was time for optimisation ....

Tim blakemore and i mapped both cylinders using the nemisis ecu . Obviously Tim did the dyno sampling and (under his instruction) i changed the fuel maps to experience my first time mapping of the nemisis . I think the nemisis is a really good piece of kit not that i will ever get involved with fully learning the dyno . Building engines and playing with cylinderheads are my thing , plus if i made the maps it would take all day and i would never have a pot to piss in . Ill leave the mapping to the experts like Doug , Tom , Brad and Tim .

By 3.30pm we had reached full throttle mapping With a power output of 167 DIN hp . Unfortunately the coil started to play up causing a misfire between 9200 and 9750 . Once this misfire is fixed tim is confident it will be a very near 170bhp rocket

Its gonna take a few days to collect the run filesbut they wil be posted here so keep checking back

[El Gladiateur]

You know what Chris?....PICS!

Congrat for the job!

[chris steedman]

Big disappointments !.

After a trip to the dyno this morning to collect the run files the last ten or so full power runs after fuel adjustment were found not to have saved

We now have to wait a month or so untill it comes back for fine tuning of the ignition maps.

Bummer

Sorry peeps

[TomTom]

I applaud your efforts chris and hope the misfire gets solved!

[brad black]

altho i never experienced it, i was told some 998S had a miss about then that was fixed by pulling the pick up gap down to 0.4mm or less. seemed to be unique to the model.

[moperfserv]

Yes to what Brad said. There is a Nemesis tech note about that misfire with several small adjustments including crank sensor gap and better support of the sensor, which they feel, can resonate.
The tech note mentions that Magneti-Marellli probably have developed smoothing algorithms that address that but Competition Systems is reluctant to start down that road as long as there are mechanical fixes. I don't blame them, M-M wrote the book on the subject and have, no doubt, payed the price for their knowledge.
Read about the 1989 SBK Championship and the problems Ducati had, among them FI issues.

Doug

[Old Fart]

Nothing scientific on my post but I can confirm that the bike does by the seat of the pants run a bit smoother with the pickup gap reduced.

[millemille]

Is the Ducati CPS a reluctor or Hall effect sensor (2 wire or 3 wire)?

When I've had misfire problems coming from reluctor/2 wire CPS signal discrimination problems at high rpm when fitting MoTeC ECU's to race bikes, the solution has been to take a variable resistor and place it across the two CPS wires and then run the bike up on the dyno and gradually increase the resistance until the misfire just dissapears.

Then measure the resistance of the variable resistor at the setting that stopped the misfire and attach a fixed resistor of the same value across the CPS wires.

Makes the signal cleaner and easier for the ECU to see..

[chris steedman]

Thanks for the responces guys . I too read about the nemisis being sensitive to misfiring due to sensor gaps. The manual says the sensitivity increases with the addition of a big bore kit with 2 reported cases so far! The gap has been adjusted and we shall retry it. It was only hapening at full throttle.

[desmo11]

Check out Ai-Tek VR sensors. They make a variety of VR sensors.

I would recommend a sensor that they make --high temp sensor with high sensitivity. They make a sensor that has a shielded wire that has excellent noise performance.

Given that you run the high temp, high sensitivity, shielded sensor, you will probably have to increase the air gap as the peak-to-peak voltage will be too great (increasing air gap decreases P-P voltage).

The sensor I am thinking of is 3/8-24 thread (w/jamnut), you will have to make a billet adapter block or whatever.

[jules_1972]

Any updates with Dyno Charts?
Fix from the gap reduction on the timing sensor?