Dialing in timing on a boosted stock bottom end 5.3
#41
Yes high octane spark table. I'm running a scaled tune so everything measured (airflow, g/cyl, etc.) is half what it actually is. It allows me to not max the airflow limit in the ECM or get stuck at the far right column of the spark table. I can turn up the boost, or if I had a boost control issue, and the stock ECM will command less timing. This is all with a 1 bar OS
#42
G/cyl is 1 axis of the spark table , the other rpm. How I understand it is its a calculated # based on ve , iat , map and probably something else I don't know about Lol. You'll have to log that to know where you are at certain rpm / map areas. It maxes out at 1.2 on the p59 ecu , not sure about others . Mine maxes out at about 10 lbs of boost so if I was running say 12 lbs the timing would be the same. Not a problem that I'm worried about as it spends no time there , pretty much 7lbs or 15 . If I wanted to maximize power at say 12 lbs I suppose I could lower the inj flow tables and the ve table to achieve ideal timing at all boost levels - this would take me a while and just don't think it's worth it. My low octane table is the high octane table ×.85 , read thar somewhere
#43
G/cyl is 1 axis of the spark table , the other rpm. How I understand it is its a calculated # based on ve , iat , map and probably something else I don't know about Lol. You'll have to log that to know where you are at certain rpm / map areas. It maxes out at 1.2 on the p59 ecu , not sure about others . Mine maxes out at about 10 lbs of boost so if I was running say 12 lbs the timing would be the same. Not a problem that I'm worried about as it spends no time there , pretty much 7lbs or 15 . If I wanted to maximize power at say 12 lbs I suppose I could lower the inj flow tables and the ve table to achieve ideal timing at all boost levels - this would take me a while and just don't think it's worth it. My low octane table is the high octane table ×.85 , read thar somewhere
#44
You are describing scaling the tune. Thats why i said a flat 50%, it makes the math easy and solves the issue you described where you're living on the final column in the table. It's not that bad to do and I have a sticky in sig. It was made foe the MAF but works just as well in speed density.
#45
the "torque loss from spark retard" table (ls1) sais:
3° 0.2%
6° 0.9%
9° 2.5%
12° 5.0%
15° 8.4%
i figure they must know how it is and it corresponds with my playing around quite well. you do dont loose much power by being conservative by 5° or so. increase boost, not timing. most of these engines are "all in" well before 3000 rpm btw.
(the same holds for fuel: unless in real competition, run it rich. the ls7 runs 10.8 afr stock n/a.)
3° 0.2%
6° 0.9%
9° 2.5%
12° 5.0%
15° 8.4%
i figure they must know how it is and it corresponds with my playing around quite well. you do dont loose much power by being conservative by 5° or so. increase boost, not timing. most of these engines are "all in" well before 3000 rpm btw.
(the same holds for fuel: unless in real competition, run it rich. the ls7 runs 10.8 afr stock n/a.)