Forced octane scaler

[limited cv8r]

If "A0000 Forced octane scaler" is enabled and "A0001", "A0002" set to 100% can the pcm still pull timing for anything, eg IAT temps etc?

[Tordne]

A0000 overrides only one thing and that is the Adaptive Spake Scaler, which can be viewed with the GM.ASPARK PID. This Scaler purpose is to decide the balance between the High and Low Octane spark tables.

If A0000 is Enabled then this scaler will be fixed to the value of A0001. this only means that the balance between the High and Low tables will not be affected by KR, which would normally degrade the scaler in favour of the Low Octane table.

A0002 is the maximum value that the scaler can achieve, even if the A0000 is Disabled. So, A0002 is generally always 100 so that you can run fully from the High Octane table under normal conditions.

Spark timing will still be affected by all ECT and IAT tables in any event.

Hope that makes some sense

[joecar]

So to slide between the HO and LO tables, set A000 to disabled...? Would that be correct...?

[SSpdDmon]

To slide between HO and LO tables, you need to first set the ceiling (the max it will move towards the HO table) in A0002. If you want to be able to fully scale up to the HO table, A0002 needs to be 100.

If you want to keep the stock learning between HO & LO based on observed KR, you leave A0000 disabled. The car will then adjust according to how much the knock sensors are tripped (just like the day it rolled off the show room floor).

If you enable A0000, it will no longer learn between HO & LO. It will then be fixed to the number in A0001. If you enter a scaler of 50, then it'll calculate timing based on half the distance between the HO & LO tables. In other words, if 28* is commanded at 6000rpm/.80 grams per cyl in the HO and the LO octane table is 24* for that same cell, the commanded timing with A0001 set to 50 would be 26*. Make sense?

I hope I explained that right (having never looked at the OS).

[joecar]

Ah, I see now... thanks Jeff, that makes sense.

[SSpdDmon]

Ah, I see now... thanks Jeff, that makes sense.

SSweet....