Originally Posted by
chevota
I set my Target Lambda idle/cruise to 1.02 and it didn't work. Command was still 1.00 and O2's at idle/cruise still ~.980 or richer. So I set 2nd Fuel to 1.02 as well, and still nothing, but no surprise there. The only other place to set is Cat Heating, which did work, but only for 30 seconds or so after cold start and never again.
So I guess some other map or minimum setting we can't see, is blocking me.
Hmmm, maybe Power Enrichment will override it. That'll be more tricky...
outlaw:
Mine switches to the 2nd fuel map anytime I lean on it, so it's my main fuel tuning tool, but I also have to dial in Target.
Here's the problem; I can leave Target oem, and it works great, but too lean. At 4760rpm it's .930 and maxes at only .891, so ping/retard city until 2nd fuel kicks in, which takes a couple seconds. So I made Target richer to combat that, but it's not as rich as 2nd. It's just barely rich enough to not ping in that couple sec before 2nd kicks in.
If I make Target match my richer 2nd fuel, so there is no delay in enrichment, I lose power during that transition period, which makes it soggy and boost takes longer to get since it's soggy.
So it's a delicate balance of fuel and time to just barely avoid ping, but no more. The result is a much crisper throttle and more power.
I'm still at a max of .830 on my 2nd fuel and so far so good. Rekon I'll go to .840 soon. Per my brain, I think I should be able to go to .850, assuming my 45-50% Ethanol content. Just like the leaner Target helps, a leaner 2nd fuel helps too. My current .830 nets a noticeable power gain over .800, and again quicker Tbo spool. Between the two fuel maps it makes a big difference in the time delay between flooring it and pushing me back in the seat. Huge difference.
As for Delta, you're saying it's an urgency, or a timer, to switch from Target and richen fuel. That makes more sense than my theory about being a % of Target vs 2nd. I guess I'll have to experiment by using drastically different #'s to see what it does.
The part about 2nd fuel being ignored and some Ethanol map used makes no sense to me, for my car that is. I wonder if maybe M157 motors are wired that way? Just a guess because I noticed M157 has a rich Target but 2nd fuel is way too lean, so I can't imagine that motor using 2nd. Mine, for sure, uses 2nd fuel. In oem form my Target and 2nd maps are identical. Weird... Like they weren't even trying.