Ajusting Dwell
07-21-2009, 08:15 AM
#1
Ajusting Dwell I am having trouble and I wondered about adjusting the dwell tables to get a hotter spark?
What tables to adjust and how much?
I just got my setup running. GT55, 410 gen 3 LS motor. 9-1 comp. I have a decent base tune from before I switched to FI and i am using e98. Every time I get into it it falls flat on its face. As soon as the PE mode engages, it comes out of closed loop. Once the A/F drops below 12.0 it fall flat on it's face. I am using a retracted tip tr7 gapped at .028, it appears to me to be blowing the spark out? I put a set of tr8 gapped at .020 but havent gotten to test it.
What tables to adjust and how much?
I just got my setup running. GT55, 410 gen 3 LS motor. 9-1 comp. I have a decent base tune from before I switched to FI and i am using e98. Every time I get into it it falls flat on its face. As soon as the PE mode engages, it comes out of closed loop. Once the A/F drops below 12.0 it fall flat on it's face. I am using a retracted tip tr7 gapped at .028, it appears to me to be blowing the spark out? I put a set of tr8 gapped at .020 but havent gotten to test it.
07-21-2009, 01:41 PM
#2
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Adjusting dwell will not necessarily give you a hotter spark. The dwell is set by the factory for proper coil charge time. If the ignition coil becomes "saturated", you will get a full charge, and as much spark energy as that coil can provide. Increasing dwell beyond coil saturation will only cause the coil to run hotter and fail sooner with no corresponding increase in spark energy at the plug. If you truly suspect ignition wash-out, the only way to know for certain is to perform a secondary ignition voltage/oscillation test along with a current test on the coil primary circuit. If washout is occuring, you will see multiple jumps to the spark-initiation KV output, and a clamped primary ignition current waveform. If this is the case, you'll benefit from going to a multi-channel ignition amp that uses conventional coils. It's and expensive upgrade, but the only true and valuable upgrade from the stock coil setup.
07-25-2009, 07:55 PM
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Adjusting dwell will not necessarily give you a hotter spark. The dwell is set by the factory for proper coil charge time. If the ignition coil becomes "saturated", you will get a full charge, and as much spark energy as that coil can provide. Increasing dwell beyond coil saturation will only cause the coil to run hotter and fail sooner with no corresponding increase in spark energy at the plug. If you truly suspect ignition wash-out, the only way to know for certain is to perform a secondary ignition voltage/oscillation test along with a current test on the coil primary circuit. If washout is occuring, you will see multiple jumps to the spark-initiation KV output, and a clamped primary ignition current waveform. If this is the case, you'll benefit from going to a multi-channel ignition amp that uses conventional coils. It's and expensive upgrade, but the only true and valuable upgrade from the stock coil setup.
