Closed loop area?

[mikef4uk]

Anyone know where the S1000RR ecu uses closed loop? .............on other bikes it's normally something like up to 20% throttle and 6/7000rpm, anything outside those and they revert to open loop

[Mr. T]

Dynojet answered this very question awhile ago. (just search for DJ posts)
They said Its as high as 50% at 6000rpm and 15% up to 9000rpm.

[Stang10189]

what do u mean closed loop and open loop? been riding sport bike sense i was 16 and never heard this terminology. maybe i know what you are talking about but refer to it with different terms but if not i would like to know what your talking about. thanks for the explanation up front

[mikef4uk]

Originally Posted by Stang10189

what do u mean closed loop and open loop? been riding sport bike sense i was 16 and never heard this terminology. maybe i know what you are talking about but refer to it with different terms but if not i would like to know what your talking about. thanks for the explanation up front

Closed loop= ecu responding directly to feedback from o2 sensors in exhaust

Open loop= ecu just runs off installed fuel map and taked no account of information from o2 sensors

[viperclaw]

Closed loop is when the bike would run with fewer emissions and supposedly more efficiently. In reality it would not be truly efficient--in the power sense--but more so in the unburnt fuel sense. It is probably a bit lean in the close loop area of operation so that the bike can pass Federal or state emission standards.
The loop means that the ECU is taking into account things before combustion such as air temp and density, throttle position, engine speed, and others parameters, and is measuring through the use of the oxygen sensors the efficiency at which it is performing. Hence the loop from beginning to end. It adjusts injection and ignition timing to burn more efficiently--less unburnt fuel in exhaust gases--while maintaining optimal power.
Open loop it does not take into account the oxygen sesnor input. So it is no longer a "closed" loop. It only cares for the input side of the equation.

[RansomT]

Originally Posted by mikef4uk

Closed loop= ecu responding directly to feedback from o2 sensors in exhaust

Open loop= ecu just runs off installed fuel map and taked no account of information from o2 sensors

and even if you don't have 02s, most of the Japanese bikes read from MAP sensor to determine fueling and timing until 11-20% Throttle position. And that fact is why tuning with a Power Commander sometimes causes issues at lower/cruising speeds.

[viperclaw]

I think the MAP (manifold absolute pressure?) sensor is used in the older first generation BMWs with fuel injection. These didn't have 02 sensors and adjusting the idle mixture is possible. You would check it with an exhaust gas analyzer while tuning--at idle only.
I think that when they started using 02 sesors the MAP sensor was no longer used. The older ones that use the 02 sensors the fueling cannot be adjusted, however timing could be adjusted but just base timing. Advance would be done by the ECU so timing would be set by the recommended numbers.