I'm trying to understand spark timing at WOT on the EcoBoost to be able to evaluate a calibration change (AKA "tune") when I get one. I'm also interested in figuring out how much octane and ethanol the factory tune can make use of. I used to go a little beyond E10 on my CTS-V and STS-V with ethanol to lean out the mixture a touch and make more power through the combination of more alcohol than the factory setup compensates for, plus the extra blend octane that ethanol provides.
On my data logger, it looks like starting from a dead stop, the EcoBoost starts out a WOT run under vacuum running fairly normally (without much timing advance under load) as if it were a NA engine, not taking advantage of premium octane at all while still under vacuum.
As it nears the crossover from vacuum to boost, the car pulls timing way back until it gets into boost territory.
Once in positive boost, the ECU runs timing aggressively up to 20+ while at WOT.
I'm going to making a few runss with an almost empty tank and a warm engine on my normal 93 octane. Then I plan to fill it on 87, burn the 93 out of the lines, then make the same runs on mostly 87 and compare results under the similar conditions.
On my data logger, it looks like starting from a dead stop, the EcoBoost starts out a WOT run under vacuum running fairly normally (without much timing advance under load) as if it were a NA engine, not taking advantage of premium octane at all while still under vacuum.
As it nears the crossover from vacuum to boost, the car pulls timing way back until it gets into boost territory.
Once in positive boost, the ECU runs timing aggressively up to 20+ while at WOT.
I'm going to making a few runss with an almost empty tank and a warm engine on my normal 93 octane. Then I plan to fill it on 87, burn the 93 out of the lines, then make the same runs on mostly 87 and compare results under the similar conditions.
