EGR is shut off at WOT but then you have a preheated intake manifold stealing some initial power. I am not too concerned about this but at part throttle when the EGR is on there is less torque to lug the gears so downshifts happen sooner.
I am able to tweak the EGR flow through the ECU. There is also a parameter to advance timing with EGR flow which I did. However since this motor has no knock sensor I did not want to be overly ambitious.
Another thing to note:
During extended coasts the ECU enters "coasting fuel shut off" mode. I don't know if all the injectors are shut off or if fuel is just reduced but The EGR flow during this time is jurastically increased. The stock values had the ECU enter "C.F.S." after 15 seconds of coasting. I changed it to enter "C.F.S." after three seconds of coasting. One thing I really noticed was a huge increase in drive line drag to the point where you would slow down going down hill. To improve the driveability, I totally disabled coasting fuel shutoff.
2x EGR flow might be a bit excessive as a first step.
Quote:
Originally Posted by EdKiefer
Extra EGR flow should only affect low rpm/part throttle conditions, it should not affect WOT (EGR should be closed)
If your able to tweek ECU , I would try raising spark timing in part throttle/cruising area (when EGR is on). The stock ECU probably does this also so some testing would be needed .
For sure adding extra EGR will make the car less responsive and need more throttle (thats what you want, and if all goes right some extra MPG might happen) .
2x increase sounds a little extreme , I would start lower % and test, work your way up .
|