Injector angle tuning

[dkw_dude]

Hi
I'm curious about injector angle tuning (at which crank degree# injector closes), have it on my VEMS, currently disabled.

AFAIK (from the www) the injector should close just before the intake valve opens (to avoid spraying fuel more or less directly on the cylinder walls). But others say thats could be bad because fuel hits backside of valve and thereby the fuel atomization will suffer. Also injector size matters (small injectors with close to 100% duty cycle on full boost will not benefit as much).

Anyone tried to set up injector angle table, and what is your experience and table values (and engine/cam/cam timing/injector size values).

Cheers, Leif-Helge

[Kieron20V]

All the books on engine management I read suggest that firing the injector onto the back of a closed valve is the way to do it as the valve will actually be hot enough to vaporize the fuel on contact and help with mixture formation.

[dkw_dude]

Thanks for the input. Activated injector angle tuning and set it at 370 degrees (stock 3B cams, opens 3 degrees after TDC) before TDC at 1500 rpm, ramping up to 400 at 7500 rpm. Seems to run smoother and stronger, especially at low engine speeds. All according to the butt dyno