What's holding up DFCO in my tune?

[cp-the-nerd]

cp-the-nerd_09-Malibu-LY7_v3.55.hpt

I've changed the enable/disable rpm to 1300/1000 for better access (it was 1600/1200 stock). Enable speeds are fine. I've dropped the blend time from 150 across the board to 50, raised the entry spark (this is the correct way to get it to enable sooner, correct?), and dropped the Fuel Cut Delay significantly. I'm still looking at 4-5 seconds before DFCO kicks in on highway coast/decel.

Any input is appreciated. I haven't touched CylAir because I haven't been able to find any good info on it. Haven't touched throttle enable/disable either.

[jtrosky]

I wish I could help, but I had absolutely no luck tuning DFCO on my 2012 Impala either. I was going for the opposite effect (DFCO coming on less often), but I couldn't get the parameters to acutally change anything successfully. I ended up disabling completely.

I have read other posts that talked about the entry spark tables and blend tables to make it come on sooner though (although, don't believe the poster ever confirmed if it worked or not). Interestingly, I don't even have those tables on my 2012 DFCO screen...

Sorry I can't help more - at the very least, this post serves as a 'bump" (tough getting answers in the V6 section!) :-)

[cp-the-nerd]

I agree, getting answers in this section is very tough. And searching through DFCO threads yields a lot of poor results. People are constantly posting contradicting strategies, and every different ECM seems to have different different DFCO attributes.

For an experienced tuner, this is 5 minutes to look and respond. For me alone, it's going to be hours of trial and error over the course of a month or more. Throw me a bone!

[CatnipG5Bandit]

Try setting your blend times to like 1/3 of that. Mine are at 15 and I'm tempted to reduce them further. Also severely lower the crank references required in "DFCO Fuel Cut."

Let it be known I'm not some expert, but rather I'm sharing what I've learned from experimentation. The way I understand, DFCO works in steps. Obviously your car has to meet the requirements such as coolant temps and RPM. Step 1: you go below the TPS threshold, which BTW I don't recommend changing because the car will enter DFCO while cruising at low TPS levels, even if you change it by as little as .05. Also messing with CylAir has done nothing for me. Step 2: The vehicle blends into DFCO spark. The more quickly this happens the more quickly you enter DFCO. But then you still have Step 3: Blend time from completely entering DFCO Spark until actual fuel cut. So in theory if you reduce those things dramatically then you reduce DFCO activation time. My E37 doesn't offer RPM enable so I can't change that, but I've had good luck so far with the above theories.

[cp-the-nerd]

That's a HUGE help, you're awesome!

Also congrats, you just made it into my 12 page Word document of tuning strategies I've compiled from this forum.

[CatnipG5Bandit]

Lol thanks. I'm away from my laptop now, but if there is a blend time going from your main spark table to your idle spark table maybe that can affect it too.

[cp-the-nerd]

Hey, I turned the crank refs way down, 15 for both the entry blend and the dfco delay with pretty minimal improvement. Still feels like there's something in the way of my changes.

I'll be honest, the blend time from main spark to idle is over my head. If you have a moment, I'd appreciate if you could push me in the right direction. I don't know what I'm looking for. Either way, thanks for helping thus far.