Air/fuel Ratio Variations in the Ducati 996

29 Мар 2015 | Author: | Комментарии к записи Air/fuel Ratio Variations in the Ducati 996 отключены
Ducati 996

Air/fuel Ratio Variations in the 996

For an excellent education in the operation of injection, you should got to the Sigma site. Neil Spaulding the help of Duane Mitchell has ‘the’ article on the Weber-Marelli used on Ducatis. Sigma/weber.html Sigma/weber-ultimap.html

Are you done reading all of OK!

Then you know that are several sensors that are to adjust the fuel flow, the main fuel map. are;

Coolant temperature

Air temperature sensor

Barometric sensor

Plus, the two critical which directly control flow.

Injector flow

Fuel pressure

Shifts in the of the sensors can cause a shift in rate due to the information they to the ECU and the correction values written the tables on the chip.

Injector rate has a direct influence on the flow. The intention is that the are within a couple percent of one but I’ve seen a little than that on our injector bench.

Fuel pressure change the fuel flow as the root of the pressure difference. seen from 42 PSI to 45 PSI. 3 Bar is 43.5113 PSI.) That to a 3.5% difference.

I would imagine that, the resultant fuel flow across any model line into a bell curve.

The arises; ‘Was the calibration on a bike that fell in the middle of that bell

Answer; ‘probably not’.

is no surprise that my experience me to wonder how any two bikes can run OK on the same map.

A point about

Chips don’t ‘go When there is a change in the way engine runs, it is your or fuel system that’s not the chip. The data on the chip not ‘shift’.

It can be destroyed, by exposure to light, but it doesn’t go lean or in small areas.

When are ‘burned’ the final step is a which verifies that it is to the file from which it was Not close, identical!

An explanation for may appear to be air/fuel ratio over time is that the ratio is near either the or rich limit and fuel injector flow, or volumetric of the engine changes enough put it mis-fire.

About the charts that

The upper portion of the graph power and torque, the lower is air/fuel ratio. The X axis is The Dynojet air/fuel ratio is not quite real time, but close, the delay is around a

That means that in air/fuel ratio follow on the power/torque traces by 500 to 1000

Duane Mitchell (FIM) his fuel maps on bikes have the cam timing set to stock specifications (no. that mean that if you haven’t anything to your bike, the cam is ‘stock’.)

The best way to assure your bike and fuel map are on the same page, is to have the cam set to stock specs. For improvement in efficiency, having the ‘squish’ set to an optimum dimension is the final (All of this falls the Sigma Performance ‘Full category.)

The bikes used in the two charts belong to Andy and Vern Nichols. Neither of bikes have had the cam timing or the clearance adjusted. However, the cam variation on stock bikes follow a pattern, so there is a that the cam timing of these may be the similar.

Andy’s used a stock chip while Vern’s was my experiment with the maps and copied to a 916 chip. The firmware with the 996s has some (a topic deserving of it’s own so, I copied the maps and set-points the chip developed for Andy’s I’ve used Andy’s DYNORUN.014 in blue on both

The following chart shows the two 996s with 50mm systems. The WOT air/fuel ratio of of these is close enough it is within test-to-test variation.

For purposes, these engines are as to being identical as any two are likely to be.

The above were obtained significantly different WOT fuel

As an example, the injector time at is 13.9mS on Andy’s chip and on Vern’s. 10.79% more for

At 8250RPM the injector time is on Andy’s and 15.6mS on Vern’s. more for Vern’s.

If you read the articles, you’ll that the injector time is by 2 for the 4 injector systems so the map values are twice the actual injector That’s good, because are only 14.55mS available at

Ducati 996

The chart below shows final run (blue) and Vern’s the identical main map.

As you can the air/fuel ratio isn’t close. The difference between and 13:1 (at 7500RPM) air/fuel is 7.69%.

These bikes the appropriate fuel adjustments) nearly identical power the first chart.) Yet, the identical fuel times, the ratio is nearly 8% different.

this much variation one system to another, you can see that you expect one chip to fix everyone’s

Vern’s bike was tested a years ago and I ended up using the that came with his intermediate system. (see the on the 3rd chart) It performed alright, so I it, until now.

Below is the run and that earlier run from 996 (DYNORUN.041.) The chip in this example was supplied with the intermediate system.

There is some break-up at the which might be caused by the richer mixture at the top.

illustrates why some bikes run with the one chip and others like another.

And finally, two with 50mm intermediate and stock chips (074UCH.) are not the same bikes used in examples.

The air/fuel ratio from one bike to another is From the same chip.

This report illustrates I’ve been seeing day for years. Every bike at least, small adjustments, need more.

Let me say this If I said that 95% of the bikes I need adjustment, 95% of the people it would assume they are in the 5% that don’t need Don’t lie to yourself, your will respond to tuning.

I repeat something (in this the previous sentence) people to react like I’m kind of asshole. Rest that I am an asshole, but, react that way because it makes them actually up to the point that is just rather than ignore or it.

It isn’t an accident that FIM chips are adjustable. Like any chip, they may not be perfect ‘out-of-the-box’, but they can be adjusted.

kidding yourself if you think you can buy a chip and get the best performance.

The has to have the complete, from-scratch and then it has to be adjusted to optimize it.

If you check your work, you can it’s perfect!

Ducati 996
Ducati 996
Ducati 996
Ducati 996


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