LGAFF
05-29-2010, 12:01 AM
1)Note from why new 400hp Ford motor doesn't need direct injection:
As a Coyote team engineer put it, "On a naturally-aspirated engine, the biggest benefit of DI is charge cooling-and it's a volumetric efficiency benefit and not a tolerance benefit. We squirt the injectors while the [intake] valve is open, and it's open a long time, which we haven't done before. It seems simple and gets you half the benefit of DI-for no costs at all."
The only apparent downside is cylinder-wall washing at low engine speeds, so the injector is limited to closed-valve periods at low rpm. Also, the camshafts change valve timing, so that's something else to synchronize with the injector in the engine management calibration.
2)Change the firing order? the old 4/7 swap?
I think you might need revised cams for the second?
As a Coyote team engineer put it, "On a naturally-aspirated engine, the biggest benefit of DI is charge cooling-and it's a volumetric efficiency benefit and not a tolerance benefit. We squirt the injectors while the [intake] valve is open, and it's open a long time, which we haven't done before. It seems simple and gets you half the benefit of DI-for no costs at all."
The only apparent downside is cylinder-wall washing at low engine speeds, so the injector is limited to closed-valve periods at low rpm. Also, the camshafts change valve timing, so that's something else to synchronize with the injector in the engine management calibration.
2)Change the firing order? the old 4/7 swap?
I think you might need revised cams for the second?