I tuned my LS6 when I first got it running NA.
Next I turbocharged it I rebuilt it with less compression then retarded the camshaft 4 degrees because I spend a lot of time near redline.
I?m getting a lot of spark retard at anything close to 56kpa and above. Currently about 4 degrees per cell.
Can CAM timing cause spark retard?
The knock sensors are new GM units.
Note: The old engine was 11 to 1 cr. At the same cylinder airmass I was running 28degrees of advance without any spark retard. The new lower compression engine (9 to 1cr) is running the same timing before boost and the ecu is retarding the advance 4 degrees at the same cylinder airmass.
And some more info if you?re interested.
Some background. I have an LS6 forged bottom end with 9 to 1cr. Running GM P01 computer. Light car 2700# 4 speed manual transaxle. I run 92 octane and usually add a gallon of 110 to 10 gallons of 92. It is turbocharged running between 4 and 13psi of boost. The timing table is set with about 12 degrees of advance on tip in at 105kpa and backs quickly off to 9 degrees at 4psi or greater.
I don't hear any ping or knock, but it's hard to hear anything above the exhaust, etc.
There's no reason it should be retarding the timing and I'm just trying to figure out what I can do about it. Can I dumb it down? Turn down the knock sensitivity?
Seat of the pants dyno says there's a lot more in there...
Reply With Quote