SD mode and knock sensors
Thread Starter
Teching In
Joined: Aug 2016
Posts: 18
Likes: 1
SD mode and knock sensors Im running an LS1 2002 engine in SD-mode without MAF sensor. From what I've read the PCM switches over to the Low Octane Spark Table when it flips over to SD-mode. A recommendation says one should therefore copy the high octane table into the low octane table. However, if the knock sensors detects knocks it will switch over to the low octane table (which it's already using due to MAF fail and SD mode). Are these assumptions correct or not? If they are, is the use of knock sensors pointless or...?
So my bottom line questions is: Is there a way of running the engine in Speed Density Mode (MAF less) and maintain the intended functionality (spark retard) of the knock sensors?
Thank you!
So my bottom line questions is: Is there a way of running the engine in Speed Density Mode (MAF less) and maintain the intended functionality (spark retard) of the knock sensors?
Thank you!
The knock sensors will still function normally. When they hear knock, timing is reduced by the amount in the various tables.
Whats lost is the ability to gradually shift over time to the low octane table with less timing.
I always make both tables equal equal to be sure I’m getting the desired timing.
Knock sensors are valuable. But remember that to act and remove timing, they have to hear it first which means the knock event has all ready happened.
Whats lost is the ability to gradually shift over time to the low octane table with less timing.
I always make both tables equal equal to be sure I’m getting the desired timing.
Knock sensors are valuable. But remember that to act and remove timing, they have to hear it first which means the knock event has all ready happened.
On The Tree
Joined: Jul 2005
Posts: 161
Likes: 2
From: Wokingham, United Kingdom
BSON,
Your assumptions are correct.
EFI Live has a customer operating system that re-enables both Hi and Low Spark tables so that Knock retard actually works in SD (MAF-Less mode).
Rgds
Jim
Your assumptions are correct.
EFI Live has a customer operating system that re-enables both Hi and Low Spark tables so that Knock retard actually works in SD (MAF-Less mode).
Rgds
Jim
TECH Fanatic
Joined: Oct 2014
Posts: 1,220
Likes: 179
From: Virginia
They still aren’t really needed unless you run 87 during the week or something, and need the ride the knock sensors and get that knock learn factor on... lol.
