Pump Gas Timing
#1
Pump Gas Timing
Well i started looking at my tune last night for my le2 383 11.7cr, and noticed that my timing at wot, is about 32-34 degrees i was think it should have a little more timing in it but before i start messing with it i wanted to see what kind of total timing u guys are running. im also spraying 250shot but im pulling 10.5 degrees with my 685 box for that. So what kind of timing are you guys running??
#2
I just had my '93 on a Mustang chassis dyno last week, and I logged spark timing using TunerPro RT and a Moates.net APU1. I picked up more and more power by progressivly stepping timing down from the stock settings to 30 degrees at WOT from 2800 RPM to redline. No knock retard at all with those settings. I was getting alot of knock retard before, lost 20 HP above 4500 RPM in fact. Power peaked at 261.5 HP at the wheels, and the spark timing actually peaked at 34 degrees even though the program called for 30.
#3
well it sound like you are having a knock retard problem with the mods in your sig theres no reason you should be getting knock retard with 38degrees of timing...do you have a lt4 knock module..
Last edited by 383racecar; 05-19-2008 at 12:30 PM.
#4
'93s do not have an external knock module. I thought it was false knock at first also, but when backing down timing causes less knock retard, then there was actually a knock causing the problem. On my car, actual spark advance seems to be a bit more than what the tune calls for, so that was part of the problem as well. The heart-shaped combustion chamber of the LT1 does not seem to need all that timing.
#5
The pcm automaticly adds timing in the high rpm ranges. Even though the tuning might call for 36 degrees, by the time you rev close to 7000rpm you'll have close to 40* of timing. I've seen this numerous times logging runs on the dyno.
#7
In the past I ran this test with an angle grinder on a spare Opti and 10 degrees of timing in all tables and got the following:
400-700rpm = 10 degrees timing
800-2100rpm = 11 degrees timing
2200-3700rpm = 12 degrees timing
3700-5300rpm = 13 degrees timing
5300-6300rpm = 14 degrees timing
400-700rpm = 10 degrees timing
800-2100rpm = 11 degrees timing
2200-3700rpm = 12 degrees timing
3700-5300rpm = 13 degrees timing
5300-6300rpm = 14 degrees timing
#8
My Hawk had a 383 with 11.3 SCR. I ran somewhere around 34-35 in the upper range reading with DataMaster. Best torque with this timing was proven on a dyno. You should be fine in the area you indicated. The gain you MIGHT have is not worth the effort put upping the timing.
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