Where does $88 idle ve and main ve begin in real world?

[f85gtron]

Where does the idle ve table stop being referenced and the main ve table pickup? I'm curious if it's when just 0 throttle, or more to it than that?

[RobertISaar]

it has been a while since I've used $88, but there is a TPS threshold.... it should set a flag in the datastream IIRC, I would have to look into it further to be certain. if not, a flag could be setup to indicate which is in-use.

[f85gtron]

There is a flag and counter for idle, so am I to assume that's when it references that table? Its simple enough, it almost makes sense :) .
I'm wondering because my decel blm are dropping to 118 and I can't figure out how to correct that. I was thinking my table are screwy, but now I'm thinking I should look else where.

[RobertISaar]

okay, here's the logic behind the $88 VE table determination:

base VE table is looked up and stored.
byte 2A, $80 is tested to see if idle conditions met(should be in the datastream). if so, idle VE is used unless above 1600RPM(main VE is forced on here).

and that's it.... just watch for that flag to come on and then check RPM to make sure it is below 1600RPM and you'll know which table is in-use.

I'm wondering if you're running into the alpha-n settings with your calibration.... that doesn't rely on the VE table at all and can be used in exactly two situations: idle and decel. a flag turns off one and a set of 6 or 8 scalars turns it off for the other.

[f85gtron]

Alpha-n? I've seen it, but not sure I understand it. What should I look for. I thought that was for maf setups?

[RobertISaar]

RPM Below Which can be Alpha-N (KIDFRPML)
TPS% Below Which can be Alpha-N (KIDFTPSL)
MPH Above Which can be Alpha-N (KIDFMPHH)
MAP Above Which can be Alpha-N (KIDFMAPH)
MAP Below Which can be Alpha-N (KIDFMPL)

and

RPM Above Which can be Speed-Density (KIDFRPMH)
TPS% Above Which can be Speed-Density (KIDFTPSH)
MPH Below Which can be Speed-Density (KIDFMPHL)
MAP Below Which can be Speed-Density (KIDFMAPL)
MAP Above Which can be Speed-Density (KIDFMPH)

determine which mode is used in non-idle situations. most of the calibrations I've played with using stock settings allowed alpha-n during most of the deceleration process and that was it.

Calculate BPW at Idle via Alpha-N (X=Yes)

^ and that is only for idle.



I've never had a reason to use the alpha-n method of airflow calc, so it is among the first things I change in a calibration that uses it. min/max the enable values and problem solved. I removed it entirely for the nAst1 mask. I did add an alpha-n idle option into it, but it's far simpler to understand and only really necessary for something with a LOT of cam, even then speed-density can still do a decent job of managing those.