On mine, stock timer was 2.5 seconds, I found that for the most part, stock settings and a 1.2 second timer gave pretty good results. If you have timer set to 0, it ends up being frustrating, you back off and it suddenly starts to cut fuel, you end up with a normal operation and fuel cut off mode and no normal coasting.
Now, my car was a factory 3.42 car, so having those gears with the fuel off, you decel. You ended up frustrated. 1.2 seconds was about as low as I could tolerate it.
My educated guess is to determine how quickly my right foot can possibly go from 100% TPS to 100% brake (guess: under .3 Secs), then make sure that the DFCO Enable Delay Timer is longer than that.
The problem with a deeper cut off, is overdrive. With in OD, it was hard to stay in DFCO for very long. If you went to 3rd, you can really run DFCO down pretty far, to around 800 rpm or so.
The way my shift strategy tables are set, I'm usually in either 2nd or 3rd (aka 3L60E); I expect most of my DFCO in 3rd.
I tried keeping in lockup at closed throttle, it also helped a fair bit to let you run the DFCO down about as low as you could. I never had it stall.
So, Disable TCC UnLock @ Low TPS? Disable TCC UnLock on Rapid TPS Decrease? Or Disable both?
(And what's the ISSF filter's problem with the prefix 'D-I-S' anyway?)
I would keep close to GM settings, maybe tweak a little on the rpm limits and of course the timer.
I plan to tweak all the DFCO constants a little bit at a time. Hope I don't stall much!
The timing really isn't a big deal, there is no fuel anyway, why would it matter? If anything, it probably protects it when comes out of DFCO so it doesn't ping right away as fuel mixture is very lean.
I'll leave DFCO Spark Retard as is; I not only fear piston/ring/bore wear, but I don't want to suck motor oil into the combustion chamber.
Hope that helps some!
If only the ISSF could get back what was lost
You've pointed me in the right direction, and helped to draw the lines within which I should remain. Thank you so much.
the trick is to stay in lockup and not have the PCM click off the deeper gear
that way the motor produces a large amount of vacuum and keeps you in DFCO
In principle, this makes no sense to me. What happens during a decel downshift that disables DFCO? (If this is the SINGLE redeeming quality of 2.56, it ain't enough.)
the stronger the motor the less youll notice the delay IMHO
as cruise TP is so tiny anyway
Just found a table whose existence puzzles me:
DFCO Enable %TPS Threshold vs RpM
I don't get it. This table seems to provide some sort of offset to the DFCO Enable Delay Timer?
A) None of the TPS values in DFCO Enable %TPS vs RpM ever exceed 9.4%
B) can't remember ever cruising with less than 10% TPS IN ANY CAR
1) How are 'A' & 'B' connected?
2) What is this table saying that I'm not getting?
3) Is this table related to why RamAirRocket needs 1.2 Secs of fueled coasting BEFORE DFCO kicks in?
4) If you set all DFCO Enable %TPS Threshold vs RpM values to zero, how would this affect DFCO Enable Delay?
with big stall the trick is mainly in the shift tables and TCC tables more than the DFCO settings
I'll never use a torque converter that won't let me haul at least seven passengers worth of weight. Don't know exactly how limits my converter's stall speed, but I think it pretty much limits me to a 12" TC.
Still, I don't know how much time I'd've wasted before fully realizing what you two have spelled out for me.
You guys are awesome! (Don't let that stop you from adding anything else that might help me or others, though