: Aftermarket Replacement Ignition Coils? Step in!



fubar569
04-04-07, 11:27 AM
So i happen to be browsing for more ideas for modifications and noticed a few places make direct replacement coils for our DIS system.

summit
jegs
MSD
Accel

has anyone upgraded the coils to aftermarket replacements and seen positive results? they range in price from 32 to about 47 dollars a piece and we require 4 to do the job...

summit is 40,000 volts - same as MSD...and Accel and JEGS are 45,000 volts

as far as other stats, jegs only seems to claim lower resistance, accel lists these stats on jegs site: Specifications include: 11% peak increase in energy over OE. 21% peak increase in voltage over OE. 21% peak increase in dwell over OE. 12% peak increase in current over OE. this information on the accel coils was pulled from summit:

Maximum Voltage: 45,000 V Turns Ratio: 75:1 Primary Resistance: 0.500 ohms Secondary Resistance: 8K ohms

the MSD coils list this information on jegs site:
Primary Resistance: .35 ohms
Secondary Resistance: 7.8K ohms
Maximum Voltage: 40,000 volts
Induction: 4.2 mH
Turns Ratio: 80:1

the summit coils list these stats:

Maximum Voltage: 40,000 V Primary Resistance: 0.380 ohms Secondary Resistance: 5,850 ohms Inductance: 4.5 mH-5.6 mH

now...alot of this is a bit over my head, but i'll assume lower resistance is better...i wish jegs had more stats listed so i could better compare...

even with 5,000 more volts out of the accel coil, it has a higher resistance. we're prolly talking mute points on a stock vehicle, but in this case what would matter more? the 45,000 volts of the slightly lower resistance of the competition?

however, which would seem to be the better selection based on what i can drag up so far? i'd do the wires within a short period of time afterwards, and i dont think the northstar would benefit a whole bunch from too much ignition work but every little bit seems to help or add up...

JimD
04-04-07, 12:47 PM
....
summit is 40,000 volts - same as MSD...and Accel and JEGS are 45,000 volts...What is the voltage figure from the OEM coil?

Not sure what you are trying to accomplish, but--- all the coil has to do is produce the voltage required to arc across the plug gap. Any voltage above that point is not doing anything usefull (or measureable). You could wind a coil that develops 100,000 secondary volts and not see any difference in engine operation as a result.

If the plug arcs at 34,567 Volts when your engine is at WOT at 6,000 RPM under a full load, more voltage is not relevant.

fubar569
04-04-07, 12:55 PM
What is the voltage figure from the OEM coil?

Not sure what you are trying to accomplish, but--- all the coil has to do is produce the voltage required to arc across the plug gap. Any voltage above that point is not doing anything usefull (or measureable). You could wind a coil that develops 100,000 secondary volts and not see any difference in engine operation as a result.

If the plug arcs at 34,567 Volts when your engine is at WOT at 6,000 RPM under a full load, more voltage is not relevant.


if the accel figures are right, 21% more peak than OEM, it puts the stock ones at a max of 35,550ish volts...

eldorado1
04-04-07, 04:41 PM
buy the red ones, that's like 30 more hp.

:leaving:

Ranger
04-04-07, 05:25 PM
I agree with JimD. All it has to to is light the plug. More is not better, but the people selling them won't tell you that.

aamusls06
04-05-07, 01:59 AM
I was actually thinking about this today, and I was gone actually post about this for some ideas. Would it be worth it?

01STS
04-05-07, 09:10 AM
If your coil packs are dead then replace with MSD or Accel. Otherwise unless you really need the few extra volts for NOS or boost then forget it. That is what I tell my customers.

fubar569
04-05-07, 09:41 AM
If your coil packs are dead then replace with MSD or Accel. Otherwise unless you really need the few extra volts for NOS or boost then forget it. That is what I tell my customers.

i would want to eventually run nitrous, but probably less than a 100hp shot...

Mountie
04-05-07, 11:11 PM
If I needed better coils, it would be MSD. I was told, the accuracy was important. I am not sure about North* coils, but in my older GMC, OEM is only 80% accurate some of the time. My MSD is a big improvment.

As high tech the North* is, do you need an upgrade? I don't know if the cost is noticable?

Ranger
04-06-07, 10:51 AM
Accuracy? Please explain.

Mountie
04-06-07, 11:25 AM
Accuracy? Please explain.

I was told by an ignition specialist that manufacturer's standard coils don't always fire accuratly. ....The spark was not consistant.

On one of our vintage dragsters, we changed to an MSD & it ran better. The components are better.

Also, there is a difference with sparkplug quality. They are not made in the same place. There are the mass produced, & the ...produced.

( China, verses the other same brand)

PepBoys purchased plugs have had cracked ceramics, where a local speedshop plug ( same brand) will not have the problem.

I have seen this!!

I have seen a Corvette shop troublshoot a miss. Not realizing the new plug was already bad. They stopped getting them at the big parts houses.