'95 PCM - Low Octane Compensation Parameters
Thread Starter
Melting Slicks
Joined: Apr 2003
Posts: 2,150
Likes: 6
From: NS
'95 PCM - Low Octane Compensation Parameters
Using TuneCat I noticed these tables in my 95's PCM image:
Low Octane Compensation Attack Gain vs. RPM
Low Octane Knock Retard Multiplier vs. RPM
Low Octane Knock Retard Multiplier vs. MAP
Low Octane Knock Retard Multiplier vs. Cool. Temp.
These settings seem to imply that the PCM has a "Low Octane" mode. If this is the case then there must be some conditions that must be met in order for "Low Octane Compensation" to be used. Anyone know how the PCM uses these?
The Retard Multiplier vs. RPM table tells me that the PCM uses 62.5% of "normal" spark advance at high RPM when in Low Octane mode - or so it seems.
Thanks
Low Octane Compensation Attack Gain vs. RPM
Low Octane Knock Retard Multiplier vs. RPM
Low Octane Knock Retard Multiplier vs. MAP
Low Octane Knock Retard Multiplier vs. Cool. Temp.
These settings seem to imply that the PCM has a "Low Octane" mode. If this is the case then there must be some conditions that must be met in order for "Low Octane Compensation" to be used. Anyone know how the PCM uses these?
The Retard Multiplier vs. RPM table tells me that the PCM uses 62.5% of "normal" spark advance at high RPM when in Low Octane mode - or so it seems.
Thanks
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
If these routines are the same as my 90, there is not a generic "low octane mode". It's activated when all the timing from the standard knock retard routines has removed.
Think of it as an additional knock retard when you put a bad gas.
-Beppe-
Think of it as an additional knock retard when you put a bad gas.
-Beppe-
