Getting a better spark @ the plugs ?
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From: SE Pennsylvania
St. Jude Donor '03 thru '26
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Getting a better spark @ the plugs ?
What can i do to get a better, fatter, higher output spark and the plugs in my 1989 coupe ? It has the original HEI ignition, I've looked a summit catalog where there is Pertonix sells a better HEI module and coils, are they enough to put out a little extra boost at the spark plugs. And I want to keep this little project on the thrifty side ? Any and all opinions are welcome, you guys are the experts. Thank you ! 
Drifting
Joined: Sep 2003
Posts: 1,363
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From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
What can i do to get a better, fatter, higher output spark and the plugs in my 1989 coupe ? It has the original HEI ignition, I've looked a summit catalog where there is Pertonix sells a better HEI module and coils, are they enough to put out a little extra boost at the spark plugs. And I want to keep this little project on the thrifty side ? Any and all opinions are welcome, you guys are the experts. Thank you !
Have you considered better wires?
Have you considered Iridium spark plugs (or at least laser platium NGKs where the platium is on the ground electrode AND the center electrode)?
Have you replaced the distributor cap?
Last edited by theadmiral94; Nov 4, 2012 at 09:00 AM.
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From: Anaheim CA
The stock coil will put out about 50,000 volts. The plugs actually use about 10,000 volts. "Upgrading" to a combination that can put out 60,000 volts does NOTHING, as the plugs are still using 10,000 volts. The spark plugs load down the coil when they fire, which is why you only get 10,000 volts.
The coil will put out maximum voltage only when the plugs are disconnected. That was a standard test that all mechanics did in the "old days" when they did a tuneup. They would pull a plug wire and see how much voltage they got on that cylinder on their trusty Sun 'scope.
To get maximum voltage at the spark plugs, make sure that the high voltage side of the ignition system is in good shape. That's mostly the plug wires. The stock GM plug wires work just fine when they are in good condition. Pulling, twisting and other abuse will definitely shorten their lifespan. Usually they go bad at the spark plug boot because of not being careful how you pull the boot off the plug. Pull on the BOOT only! I wrap my fingers around the boot and push it outward from the inside.
The coil will put out maximum voltage only when the plugs are disconnected. That was a standard test that all mechanics did in the "old days" when they did a tuneup. They would pull a plug wire and see how much voltage they got on that cylinder on their trusty Sun 'scope.
To get maximum voltage at the spark plugs, make sure that the high voltage side of the ignition system is in good shape. That's mostly the plug wires. The stock GM plug wires work just fine when they are in good condition. Pulling, twisting and other abuse will definitely shorten their lifespan. Usually they go bad at the spark plug boot because of not being careful how you pull the boot off the plug. Pull on the BOOT only! I wrap my fingers around the boot and push it outward from the inside.
