beast94

I just got off the phone with Davis Unified Ignition and they were saying that the dwell in their 8 pin GM HEI Dyna-module is about twice that of the stock ICM. I have been running this and recently when I was trouble shooting a failed coil, I placed a stock ICM in place of my Dyna-module. I noticed that there was a huge difference in how the engine ran. Do I need to change anything a parameter in TunerPro to compensate for the added dwell? I am running an EBL Flash 7747 ECM. Thanks

Chris

RBob

iTrader: (1)

The dwell times are not in the calibration, they are hard-coded. On the stock GM computer controlled distributor ignition systems the ECM controls the dwell. The only thing the ICM does is limit the maximum current.

Not sure why Davis would want to double the dwell time... Which of course is limited in time by the current engine RPM. At 4800 RPM on an 8-cylinder the time between plug firings is 3.125 msec. Subtract the .6 msec minimum firing time and the maximum dwell period is 2.525 msec.

RBob.

beast94

Would it be wise to just switch back to the 396 ICM? Also, I just purchased the Pertronix Second Strike ignition controller. Is there anything special I should do with the EBL?

RBob

iTrader: (1)

Have to wonder if the Dyna-module contributed to the demise of the coil.

I use nothing but GM ICMs. For the pick up coil, cap & rotor, good premium aftermarket pieces. For coils, mostly GM, with one car having a made in USA oil filled canister coil.

RBob.