Sarg

iTrader: (6)

So what does the box (I just noticed after looking back through my tune) Enable Open Loop STFT do? Can this actually make adjustments based on something in Open loop? If so, what will it use to determine STFT and does this apply in WOT conditions?

joecar

When OLFA is active (i.e. in OL), you can get STFT's to trim on OLFA cells that are stoich (exactly EQR 1.000).

If in OL, the OLFA has the prevailing cell, and it is stoich, and the condition is WOT, then yes STFT trimming is performed (but of course stoich at WOT is not good).

Usually the Camaro/Firebird/Corvette calibrations had this disabled, but truck calibrations had this enabled and it would cause grief when trying to correct the VE table in OLSD.

joecar

What I meant to write was this:
If in OL, and the OLFA has the prevailing cell, and it is stoich, then STFT trimming is performed, regardless of WOT.

Sarg

iTrader: (6)

Gotcha. I understood. So this is in WOT conditions but rather only when it is stoich. So why would the car not default back to closed loop in these conditions? This just all seems a bit odd coming from previous tuning experience where open loop was pretty much any time you targeted anything other than stoich. Sure there would be delays and conditions, but it would still target stoich any time you were in closed loop unless is was one of the fancy stand alone ecus that could do WOT in closed loop, which was cool.

joecar

Yes, correct, it is irrelevant of WOT.

There are various reasons for CL being prevented... if the operating conditions allow CL, then the mode will go to CL...

the key point from above was that when in CL, going to WOT does not cause the mode to go to OL... and PE enables but is not stoich, so previous learned LTFT's are modified (negative rounded up to zero) and added... (LTFT's are never added in OL).