- Thu Jul 28, 2022 7:40 am
#57936
i was just wondering on the filter algorithm or procedures for taking MAP measurements during the 720 deg of a single cylinder ITB based engine
basically there are only about 180 deg of intake time during one completed 4 stroke cycle and during 540 deg of the whole 720 deg cycle nothing really happens in the intake portion of the engine. maybe some resonance at high air velocities.
i would think it would be advantageous to just take some defined count of measurement points (i.e. 8 as a guess) during those 180 degs of intake time and average the result to get a more reliable MAP. caution needs to be taken to sync those measurements to the crank position teeth, as well as the sampling of those readings would need to be spaced apart to match the actual RPM
i realize that those MAP readings would only work for low power to mid power values and not full throttle, but at full throttle the overall air pressure and temp in accordance with a fill factor at high RPM should lead to acceptable inject time values. those reading might not be as precise as wanted but they would represent a stable value for the VE table correction values
my question now would be : how does the speeduino deal with the above mentioned issues for cylinder ITB based engines and partial MAP injection (speed density) control, as compared to to 100 % alpha N control. a reasonable powerful CPU should easily be able to process the above mentioned data volume
i hope my question makes sense and i appreciate an answer explaining my mentioned scenario
cheers Klaus
basically there are only about 180 deg of intake time during one completed 4 stroke cycle and during 540 deg of the whole 720 deg cycle nothing really happens in the intake portion of the engine. maybe some resonance at high air velocities.
i would think it would be advantageous to just take some defined count of measurement points (i.e. 8 as a guess) during those 180 degs of intake time and average the result to get a more reliable MAP. caution needs to be taken to sync those measurements to the crank position teeth, as well as the sampling of those readings would need to be spaced apart to match the actual RPM
i realize that those MAP readings would only work for low power to mid power values and not full throttle, but at full throttle the overall air pressure and temp in accordance with a fill factor at high RPM should lead to acceptable inject time values. those reading might not be as precise as wanted but they would represent a stable value for the VE table correction values
my question now would be : how does the speeduino deal with the above mentioned issues for cylinder ITB based engines and partial MAP injection (speed density) control, as compared to to 100 % alpha N control. a reasonable powerful CPU should easily be able to process the above mentioned data volume
i hope my question makes sense and i appreciate an answer explaining my mentioned scenario
cheers Klaus