#1908, "RE: Using MS for 8-Injector setup." In response to In response to 4
Originally posted by selmerguy2003 There are people on this board using bigger then 680 injectors that get a good idle and pretty good gas mialage from what I hear.
I've got 780's, and I am still able to get around 30-32 MPG if I really push it. Although, I had to lower my static pressure to around 35 PSI in order to get a good idle pulsewidth range to work with... I think mine is around 2.5ms or so. If you are idling in the 1.2-1.3ms ballpark with huge injectors at a normal static pressure of 43.5 PSI, you will have a hard time tuning idle because the resolution of the MS1 processor (which is the one everyone uses and runs the "extra" code) is only 0.1ms. The percentage difference between 1.2ms and 1.3ms is insane, almost 10%.
The only real disadvantage in lowering your static pressure is that reduces the maximum amount power you can produce. I’ve never seen my 780’s go much above 70% duty cycle around 20 PSI of boost pressure with the S16G, which is close to the practical limit of that turbo. Yes, if I bought slightly smaller injectors like somewhere between 625’s and 680’s. I probably wouldn’t have had to change the static pressure. Ideally the maximum duty cycle should be just shy of 90%.
