Adding timing
Thread Starter
Staging Lane
Joined: Oct 2015
Posts: 86
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Adding timing Ok, I know in advance that I'll get a ration of crap for asking this question... (Kinda stupid) But my quest for knowledge has outgrown my concern of embarrassment. Kinda new to the whole tuning deal but trying to learn. I hear the phrase all the time - "Add timing" What does it mean to add timing? Considering the variables we can adjust - fuel and spark- what variable (if not both) are we manipulating when we "add timing?" And how do we know when timing needs to be "added" and how much is too much? So when everybody stops laughing at my ignorance 😃, maybe you can square me away. Thanks in advance.
Please don't ever feel the need to apologize from an honest question to gain knowledge. All of us are in a continuing quest to learn more from each other.
Ignition timing is the point in the crankshaft rotation when the ECM triggers the coil to send voltage to the sparkplug. Most often this ignition timing point will be a certain number of degrees before top dead center on the compression stroke. It takes some amount of time for the flame front to extend from the spark plug across the combustion chamber. At slower engine speeds you don't need as much ignition advance (advance is a way of saying degrees before top dead center) as you will need with faster engine speed.
A typical LS1 engine will idle with 15° - 20° ignition advance and make best power at 28° to 30° advance. With the early LS engines, the ECM limited ignition advance in order to prevent detonation at high ambient temperatures, high loads, poor fuel quality. For a performance application where the user is willing to use premium gas the ECM can be re-calibrated to add more ignition timing which in turn increases power up to a point.
Ignition timing is the point in the crankshaft rotation when the ECM triggers the coil to send voltage to the sparkplug. Most often this ignition timing point will be a certain number of degrees before top dead center on the compression stroke. It takes some amount of time for the flame front to extend from the spark plug across the combustion chamber. At slower engine speeds you don't need as much ignition advance (advance is a way of saying degrees before top dead center) as you will need with faster engine speed.
A typical LS1 engine will idle with 15° - 20° ignition advance and make best power at 28° to 30° advance. With the early LS engines, the ECM limited ignition advance in order to prevent detonation at high ambient temperatures, high loads, poor fuel quality. For a performance application where the user is willing to use premium gas the ECM can be re-calibrated to add more ignition timing which in turn increases power up to a point.
Thread Starter
Staging Lane
Joined: Oct 2015
Posts: 86
Likes: 0
Please don't ever feel the need to apologize from an honest question to gain knowledge. All of us are in a continuing quest to learn more from each other.
Ignition timing is the point in the crankshaft rotation when the ECM triggers the coil to send voltage to the sparkplug. Most often this ignition timing point will be a certain number of degrees before top dead center on the compression stroke. It takes some amount of time for the flame front to extend from the spark plug across the combustion chamber. At slower engine speeds you don't need as much ignition advance (advance is a way of saying degrees before top dead center) as you will need with faster engine speed.
A typical LS1 engine will idle with 15° - 20° ignition advance and make best power at 28° to 30° advance. With the early LS engines, the ECM limited ignition advance in order to prevent detonation at high ambient temperatures, high loads, poor fuel quality. For a performance application where the user is willing to use premium gas the ECM can be re-calibrated to add more ignition timing which in turn increases power up to a point.
Ignition timing is the point in the crankshaft rotation when the ECM triggers the coil to send voltage to the sparkplug. Most often this ignition timing point will be a certain number of degrees before top dead center on the compression stroke. It takes some amount of time for the flame front to extend from the spark plug across the combustion chamber. At slower engine speeds you don't need as much ignition advance (advance is a way of saying degrees before top dead center) as you will need with faster engine speed.
A typical LS1 engine will idle with 15° - 20° ignition advance and make best power at 28° to 30° advance. With the early LS engines, the ECM limited ignition advance in order to prevent detonation at high ambient temperatures, high loads, poor fuel quality. For a performance application where the user is willing to use premium gas the ECM can be re-calibrated to add more ignition timing which in turn increases power up to a point.
there's a few tables in HPT that affects the spark timing. the 2 main ones off the top of my head are the High and Low octane tables followed by the IAT Spark table. the pcm generally looks in the High octane table but if it sees constant knock retard/detonation, it'll revert to the Low octane table.
Thread Starter
Staging Lane
Joined: Oct 2015
Posts: 86
Likes: 0
there's a few tables in HPT that affects the spark timing. the 2 main ones off the top of my head are the High and Low octane tables followed by the IAT Spark table. the pcm generally looks in the High octane table but if it sees constant knock retard/detonation, it'll revert to the Low octane table.
