tomazcebul wrote: ↑Sun Jan 30, 2022 7:26 pm
Hello All,
@mk e, many thanks for the "out of the box" thinking. If I understood correctly, I can connect two channels to one injector and then run this as a normal fully sequential setup. In this case the injectors would need to be quite large to accommodate the fuel requirements (I have seen commercial setups with two 440 cc injectors).
The other option is to actually install 4 injectors (2 per port) to make injectors smaller, which will significantly improve idle quality.
I have seen the other thread and contacted JRD McLAREN directly before posting this question (waiting for the answer...).
Best Regards, Tomaz
If you want bad ideas, I'm your guy
What you are saying is only partly right. Traditionally, as in back in the old days with low resolution ECUs and pretty inconsistent injectors the goal was 80-85% DC for idle reasons....but those days are gone. My car has 12 1000cc injectors, so idle pulses are pretty short and there is no problem sorting idle mixture. I wouldn't worry too much about that and 4 injectors wont' fix it anyway on your style ports.
On a Siamese port setup the big issue is the ONLY way to know the fuel you're injecting is going to the cylinder you meant is to only inject when 1 and only 1 intake valve is open, that is what the chart you posted is showing you, that is the MAXIMUM injector duration...so you are limited to no more than 180- degrees or 25%DC and you only get that with very mild cams, longer duration cams means short duration left for injection. So 2 injectors firing twice or 4 injectors each firing once only means changes basically nothing, the size of each injector remains unchanged as its driven by the time you have available which comes from the cam....with 4 injectors you maybe can aim them at the active valve a bit better, maybe?..that would be the only difference I can think of.
The other piece that modern ECUs have is cylinder trim. I didn't have that on the setup I did years ago and there were small differences which I figured were wall-wetting related but I couldn't fix with no trim....but it ran pretty well, well enough that I plan to try the same setup again on an upcoming build.