Ignition timing @ WOT
Team Owner
Joined: Jan 2007
Posts: 29,063
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From: cookeville tennessee
But to get back to your question are you talking about a 100% stock LT1 more r what here. Robert
Drifting
Joined: Apr 2015
Posts: 1,276
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Robert is right. You need to datalog some WOT pulls to see where it’s happy. You’re going to find a point where it may not detonate, but you still don’t want max tolerable timing but rather a couple deg less. I’m hitting 28deg advance on an lt4 but that same timing for another combination could spell disaster. Cylinder pressure and octane are only part of the equation, but they are big players.
John
John
Thread Starter
Racer
Joined: Feb 2004
Posts: 455
Likes: 11
From: Roanoke VA
Robert is right. You need to datalog some WOT pulls to see where it’s happy. You’re going to find a point where it may not detonate, but you still don’t want max tolerable timing but rather a couple deg less. I’m hitting 28deg advance on an lt4 but that same timing for another combination could spell disaster. Cylinder pressure and octane are only part of the equation, but they are big players.
John
John
Logging 1/8 mile passes with EFI Live the advance varies between 17 to 20 degrees at WOT.
It pulls timing up to -10 degrees at shifts.
Drifting
Joined: Apr 2015
Posts: 1,276
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Timing pull during shifts is normal, as some tuners command 10deg or so of min timing between shifts. I don’t like that, but it stops the car from falling on its face during a shift. I’m not so sure it’s the best thing for clutch pack life (at least on the very high HP stuff). Actual min timing would be a negative number during a shift. I would also GUESS that you should be between 20-24deg depending if you are looking around peak torque of peak HP. If you don’t think it’s happy, throw. 2 Deg in it and make a pass data logging. If you want to be on the edge, make it tickle the knock sensors and come back a degree in those areas, but even that won’t be night and day performance and it’s not worth the risk IMO.
Safety Car
Joined: Mar 2004
Posts: 4,048
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From: South Florida
Timing should peak around 24 degrees before peak torque and taper off to about 22 degrees at redline for that setup. Some cars will like a little more, some won't. Depends on how the car responds with your mods and the fuel you use.
