Anyone running this coil on their LT1? Thinking about installing due to the fact on the dyno in the upper rpms(4.5k +) my graph started getting erratic(most likely spark blow-out)

Anyways, currently I'm running the stock coil(autozone special) and was seeing if anyone has this coil on their car?


I'm using the digi 6, ngk tr6's gapped at .035", stock coil right now.

Thanks

 

I ran it in my 396 with 12.5:1 compression (a touch under 9:1 DCR).

It, along with a MSD Pro Billet Opti would miss around 5000 rpms and never get above 5500 once they warmed up. Swapped out the opti for a new GM unit and she made it to 6000 then got a miss again... though it finally reved to 7000 when cold.

Swapped in a new GM coil (10489421) and she ran GREAT clean up to 7000 rpms.

Sending the MSD opti and coil back to summit with a "polite" review. :/

Seems the LT1/Vortech MSD coil is weaker than stock (though it says it'll run more volts, a spark plug will usually spark before the max voltage is reached... the field colapse rate or the spark dwell might be different.. I dunno, don't care... they're going back).

It seems GM really knows how to make an ignition system. (This is total deja vu to those who keep up with the LS1 coil situation... GM truck packs are the ticket there as well).

Get the GM unit.

 

BTW, I run NGK TR5's gapped to 0.040"... getting pretty good at changing them with AS&M headers thanks to troubleshooting this issue.

The MSD coil that was giving me problems tested at 6700 ohms, while the two GM coils I tested were 5200 and 5300 ohms. I'm not sure what's considered acceptable resistance in the OBDII coils (I've read 8500 or less is about right for the OBDI coils), but I don't think this resistance difference is indicative of problems.

Just thought I'd pass it on... coil continuity testing isn't enough to know if you have a good one. :/ (I'd expect the extra windings on higher-voltage aftermarket coils WOULD be higher than GM by the extar length of wire needed... but its just a guess.)