TuneECU Air/fuel Ratio improvements

Using a table like this one as a template recommended by Tuneboy for Air/Fuel-Ratio impovements


do you think this might be a good table for the Roadster?


12.80 is known as the best ratio and I have leaned it in small steps depending on TP.
the same ratio for all RPM is an idea from the Tuneboy table.

this is of course depending on the ECU trying to achieve this ratio, which it does not do all the time. richen the fuel in the F1-F3 tables may be needed as well, but that is hard without a lambda to see the result.
am I right, or way off?

The standard R3 doesn't go into closed loop (use the O2 sensor) unless the value in the A/F table is 14.57, so with the table you showed, it will never go into closed loop. A lot of us have disabled the O2 sensor to avoid the ECU adapting to fuel increases we have made to reduce backfiring in the pipes, caused by a lean condition at low TP. I've seen no bad effects of disabling the O2 sensor under any driving conditions.

The amount of fuel supplied is based on the volume of air, which is the number in the fuel table, and the A/F ratio in the A/F table. If you want to tune to A/F, don't change the A/F table, get the bike tuned on a dyno and add fuel with Tuneboy, TuneECU or a PCIII.

Leif,
The stock narrow-band Lambda sensor is designed for Lambda 1=14.57 AFR. Whether or not this is the actual stoichiometric ratio of the fuel used, or not - it is close for most pump fuels. This narrow range sensor has a design range of .98-1.02 Lambda, which equates to 14.2786 - 14.8614 AFR. Not much to work with at idle and cruise, and even then, the ECU changes in an on-of manner that can cause the areas where the sensor is active to go rich-lean-rich-lean etc., as it trys to meet the target AFR in the table.

In fact, if the cells are set too rich in the AFR table, the ECU will not even use the sensor input. As for using this sensor and table to correct for mixture ratio outside of idle and cruising at steady speeds/throttle, then you are out of luck.

Now, I have yet to see an engine that produces best output at all engine speeds and loads at a single AFR. I can say that many engines tend to like an AFR of 12.8 up to peak torque rpm, and after this, tend to like a bit leaner - around 13.2 at peak power rpm.

If you want to see what is actually occuring, purchase an innexpensive Lambda/AFR meter like the Innovate LC-1 and gauge, or a TechEdge 2J1 and display. Both of these units can be set up to replace the stock sensor and simulate a narrow-band output, while logging with the Bosch LSU 4.2 sensor's wider range. Then ride the bike and log what is occuring at various engine speeds and loads. Make adjustments from here. But you still need to measure what difference in output these changes make.

I hope this helps,

-Wayne

Power-Tripp said:

Wayne

Click to expand...

Wayne, I talked to a dyno tuning shop in redwood city, ca (moto-lab.com) about dyno tuning with Tuneboy - this was several years ago. Most of it I didn't understand but he said that he tunes based on the rider requirements, which I assume would be different for a drag racer than someone driving around the city. He said he could tune for top end power, low end torque, whatever, not simply adjusting fuel to some ideal A/F, which seems to be what Dynojet tuners do. Could you elaborate on this?

Derek at Moto-Lab has been tuning Triumphs with TuneEdit for a few years, that I know about. He is pretty good from waht I hear.

If you tune to best output (max brake torque) at all points except idle and cruise, then you have best output anytime, anywhere you need it, and still get good cruise mileage.

Drag bikes, road racers, street cruisers... it doesn't matter. Give the engine what it wants at all speeds and loads. Get the mapping correct for steady state, and accel compensation, and the response will be great at all points.

No harm done. the example from Tuneboy website was not for a Rocket anyway.
thanks for the info about the Lambda and the surprisingly lean mix that the Rocket O2 sensor can read.

I've heard others say that their rocket is in closed loop most of the time, but I guess I can disregard that statement now.

I will look into buying those meters and log the real values. I may be able to alter the fuel tables after that.

my main concern is that even though a Dyno workshop could tune the Roadster using Tuneedit, there are no stock tunes for the Roadster available for Tuneboy yet. I'm stuck with fiddling the numbers myself.

Wayne at TB does not seem to release any of them, so we do not have a base tune for Tuneedit to start with. that does not feel good since he has my money and I have his software, but for no use at all.