pyro719

iTrader: (5)

Im just wondering how much I should pull on the 150 shot with the mods in my sig? I looked at my pcmforless tune in tunercats and at 100kpa from 3,000 rpm's to 6000 rpms I have 37 degrees of timing.

96lt1m6

iTrader: (31)

i sprayed 150 for a few years with stock timing no retard box at all.
best thing you can do is get on a dyno and make a N2O pass to see what the A/F looks like

pyro719

iTrader: (5)

How will I know what the best timing is on the dyno? Will more retard create a richer afr?

96lt1m6

iTrader: (31)

you should be more concerned with A/F ratio at this point

LS1Z28-00

iTrader: (8)

no it will affect how much the motor detonates. nitrous speeds up combustion so much you want to retard your timing to accommodate this change. A/F needs to be nice and rich to be on the safe side. I think my nitrous tune on my ls1 was around 12.5 or a little less, cant remember exactly. Also you can get away with more timing if you run some race fuel in it. I would recommend getting a tune, race fuel and switch to a colder range plug if you want that lt1 to live on that big of a shot.

pyro719

iTrader: (5)

I took my car to a tuner up in denver and he lost 4 rwhp over the pcmforless tune. He dropped all my timing tables to 35 wich I beleive is to low
?. I have the mallory 685 to pull timing and he had me pull 12 degrees to start. Im also running tr6's now. Im kind of forced to tune this thing my self since nobody aroun here seems to know what they are doing in tunercats. The tuner was a hp tuner. He was rushing me out of the shop as he had a big money gto behind me to tune so I Felt I was ripped off. I loaded the mailorder tune back in.

LM97Z

iTrader: (4)

Make sure the A/F ratio is right, i would go richer then 12.5, 11.7 is what Chris/Ray shoot for, you need to find out how much timing was added over stock with that PCM4less tune, if Brian did it, then ask him, i would at least pull 8* too start, then either add or subtract in 2* incromments for best MPH, but do this at the track, just make sure the A/F ratio is good 1st., you have the 685 box, so adjusting timing is at your fingertips.

pyro719

iTrader: (5)

Cool thanks alot. I guess Ill make some more dyno pulls to get the afr sorted out and then take it to the track to dial in timing.