From a performance stand point you have to view a mulitcylinder engine as a bunch of one cylinder engines attached to a common crankshaft. > https://youtu.be/rBZCnG1HwDM?t=3m17sRufe0 wrote:Hmmm OK I see what your saying but I just don't like the idea of a map for each cylinder, from a tuning point of view your effectively tuning four single cylinder engines which is obviously a pain. What about one proper full fuel map, then a modifier map for each cylinder which would just be +-1% or whatever in a 3d table? That way you still have a central table where 99% of your tuning is going to take place for ease of use.
But yes a common VE table with tables for each cyl is commonly how its done for corrections
Generally it will just be a percentage indeed.OK yeah thats reasonable. Just wondering if the same thing could be achieved with a percentage modifier? For instance at X degrees C add 10% extra fuel. That way it's not a fixed amount like "add 1ml extra" it will scale up with load and RPM.
No I am thinking of a MAF sensor, which is the most direct way of reading mass. Now a MAP sensor in a SD VE system does require an AIT sensor to correctly calculate airflow\VEA MAF needs an air temp sensor, your thinking of a MAP sensor.
I don't predict needing a map to time the fuel to valve opening, I plan to modify my engine with a unique intake system that will basically negate sequential injections benefits(and make a MAP sensor useless), regardless it's no trouble to program a basic version in. I Plan on making a few different versions just for the hell of it. Directly after valve closure, maximum time for evaporation, perhaps enable this on start and warmup. Directly before valve opening, injector would just finish as the valve was just opening. On valve opening. And some others, maybe switch between different modes for different conditions. Of course these would be offset-able, probably setup a scaling offset with RPM. All this assuming the injector pulse is short enough in the first place.
I would like to know why you think a MAF sensor requires an AIT sensor.
To be able to tell the ecu like I want to injector on the valve for better MPG or while the valve is open and not use a MAP of injection timing would make me think.
A) you will need to have a camshaft model in the ecu and a way to model it correctly
b) some load variable to go with it, just because X timing is good at Y rpm doesn't mean its the same as you add load at the same rpm
That way I could see working maybe as an additive map but not as a main ign table map. You don't take into consideration load like that.Once I've calculated the A/F ratio and injected the fuel I then need to time the ignition. To do this I will lookup the degrees BTDC in a A/F vs RPM map, calculate the time in milliseconds or clock cycles after the relevant cam position sensor using the RPM and set an interrupt.