ddnspider

iTrader: (26)

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

GMCGreg

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

ddnspider

iTrader: (26)

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.

GMCGreg

got it , I did read that and chickened out LOL. Should have done it recently when I swapped to the nnbs intake ( I'll start a thread when I have track tested it ) takes me quite a while to get the tune down for a few reasons . No1 is I'm an old carburetor guy and computer illiterate, other reasons are no dyno , just street tuned so weather , traffic and time have to line up . Honestly I like that I can just lower boost with the controller and with timing steady at 13 it makes the tune extra safe and still plenty of power for street tire use. Any updates on your truck ? Not for here but your original post

Dian

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.)