ECU tuning question

[bald.male]

What exactly does it mean when a person asks for a
"a specific RPM range and a general throttle percentage"?

[moto]

I suppose the request would be answered something like: "I'm most concerned about response/power at full throttle from 5000 rpm on up." Or whatever your concern is. If you said, "one quarter throttle around 3500 rpm" the person you are talking with would try to provide a different solution.

Just a supposition.

Moto

[bald.male]

Thanks, so would it make a difference if the bike were running down the road, in gear, versus sitting and running it on neutral?

[moto]

Thanks, so would it make a difference if the bike were running down the road, in gear, versus sitting and running it on neutral?

Absolutely! If you want to hold 3/4 throttle, say, at 6000 rpm you'll need a lot of resistance for the motor to push against. Running down the road can provide that, but sitting still in neutral provides no resistance which makes it impossible to hold the throttle/rpm combination I just specified. The motor would just race to redline (or hopefully your rev limiter).

By holding a particular speed and throttle opening you are testing whether the ECU can properly fuel the bike under a specific operating scenario.

Now without knowing what you are trying to accomplish, or even who you are talking with about rpm and throttle opening, I suggest you should think about which operating scenarios are problematic or else most important for you. It could be low-rpm responsiveness to a lot of throttle, which is useful in riding around town. Or it could be drag-race type acceleration using higher rpms. Or it could be responsiveness on the open highway for passing, say 4500 rpm at 70 mph (if that's your bike's combination). All these things would have to be evaluated while under way, instead of simulated in neutral. Your consultant (?) wants to know which is most important so that he/she can make or recommend suitable adjustments.

It might be good to have a general discussion about all this with your consultant. He/she can recommend particular riding experiments to help you decide where your most important issues are.

Moto

[bald.male]

Helpful, thanks for the thoughtful response!

[usedtobefast]

Are you working with a tuner?   In the Moto Guzzi world most guys go with a Beetle Map ( griso.org ).   Those maps have been well tested and should make your bike run great. 

A bit of a learning curve to figure out reading/writing maps, but it is great and we can do that (as in, the ECU's aren't locked like KTM/Ducati/etc).

[AZRider]

Like everything else in life, you have to compromise one thing to optimize something else. Sounds like your tuning person is either asking "When do you really notice your bike not doing what you want?" or "What circumstances do you want your bike to be most awesome?" (S)He is asking for answers like "When I womp on the throttle coming out of a corner at 3,000 RPM" or "Just trying to tiddle through parking lots at 1,500 RPM without the bike lurching."
A bike tuned for efficient long distance cruising might have to give up some punch accelerating away from a stop. A bike tuned for railing through the twisties might have to give up fuel economy and in-traffic puttering smoothness. As the computers get more advanced with "ride modes" etc., we are able to switch their programming for different circumstances. Some day they'll be smart enough to switch their own maps on the fly based on how you're riding, but that day is not here yet.

[Tusayan]

A bike tuned for railing through the twisties might have to give up fuel economy and in-traffic puttering smoothness. As the computers get more advanced with "ride modes" etc., we are able to switch their programming for different circumstances. Some day they'll be smart enough to switch their own maps on the fly based on how you're riding, but that day is not here yet.

This what a single fuel map does, by specifying the correct fuel injector pulse for any combination of RPM and throttle position.  The tuner is asking what combination of RPM and throttle opening is causing problems so that area of the map can be corrected in response. No compromise or change elsewhere in the operating range is required to do it.

The weak point of a simple Alpha-N 3-D map is that it does not provide detailed accommodation for environmental variables like altitude or temperatures, and instead simply shifts the entire fuel map up and down.  It works well regardless unless you are trying to pass smog tests or maximize fuel economy for any combination of environmental conditions.

Ride modes mainly change things that are outside of the scope of fuel injection map tuning or making the bike run properly, for example changing the throttle sensitivity to a given movement of the twist grip, or limiting throttle opening and thereby power output.

[beard]

A bit of a learning curve to figure out reading/writing maps, but it is great and we can do that (as in, the ECU's aren't locked like KTM/Ducati/etc).

The Marelli ECUs are also 'locked'.