DaveyB wrote: ↑
Mon Aug 12, 2019 12:30 pm
TZ, when looking at your VE table, it looks like you've only allocated 6 columns from 3000 to 7200 rpm for the crankcase pressure differential measurement, whilst giving 10 columns to Alpha N from 7800 to 13500 rpm? I thought that the area (in rpm) below where the pipe starts working would require finer control and thus more columns. On a separate note are you running the engine with premix or oil pump?
No, the area below (and above) the transition area where the pipe starts to work does not need as many columns as the transition area itself.
I have abandoned the VE map approach and for now are concentrating on Alpha-N multiplied by the MAP/Baro ratio.
Alpha-N is great for everywhere the airflow is consistent. So Alpha-N is good for everywhere that is not on the pipe and every where on the pipe and above 50% TP throttle position. There is only a smaller area where Alpha-N does not work well and that is in the area where you could be on the pipe and less than 50% TP. That is because air flow here is variable due to inconsistent pipe action.
Currently my crankcase PseudoMAP outputs a MAP value equal to the Baro value in the areas where airflow is going to be consistent. So the Alpha-N map here is multiplied by the ratio of 1:1 i.e., Alpha-N * 1.
And in the area where the engine should be on the pipe but the TPS is less than 50% the PseudoMAP outputs three times the Delta crankcase pressure. So in the variable air flow area the Alpha-N map is multiplied by ratio of PseudoMAP : Baro. i.e., Alpha-N * (PseudoMAP/Baro).
Anyway this is the current approach I am exploring, I will find out soon if the concept works. If Speedy gets a table that switches between AN and VE maps according to TPS vis RPM then I will try working with both maps again.