Multiple coils

Ray Menard · 05-03-2008, 08:31 PM

I saw a racer I respect very much a few weeks ago with 8 coils on his Super Stock motor. The more I think about it, the more I wonder if this might be something worth investigating. With a Super Stock motor that sees close to 10,000 RPM in the lights, logic tells me with 8 coils (one/cylinder), each coil would only have to produce a spark 1 out of 8 times instead of 8 out of 8. This time lag, although short (at 10,000 RPM, each plug in an 8 cylinder motor fires 10 times/second). If each coil had to produce only 10 ignition events/second instead of 80 ignition events/second, surely each coil would have more time to recover between events and thus produce a better quality spark.

Does this train of thought make any sense or do I need therapy? Does anyone have any experience running multiple coils on a Super Stock motor?

G Schenck · 05-03-2008, 10:13 PM

I can't remember that far back but a SS racer that lived in Louisiana had that setup in the early eighties. Made sense to me. Larry Meaux might know , the racer lived near that area , I believe.

Greg

Kile · 05-04-2008, 12:53 AM

Not a /SS car but the Accufab BB/AT, sometimes AA/AT of John Mihovetz is running a coil per cylinder on the Ford mod motor.

Jeff Lee · 05-04-2008, 12:59 AM

I see a grey area in the rules on this....unless it is a factory "distributorless" ignition. Ray, was it?

Under SS rules it says: "any battery powered ignition permitted. Distributorless ignition must retain OEM number of coils"

Under SS/GT (and above) it reads: "any battery powered ignition permitted"

So if it was a GT or Modified, I would say no problem to anything but a magneto and as many coils as you like. Ray, I think I would pursue it since you have a Modified SS.

Under SS, could you have multiple coils only if the engine came equipped with a distributorless ignition as per OEM? Or could you convert from a distributor based ignition to a distributorless ignition and then would you only have allowance for (1) coil if that's the way it came?

SSDiv6 · 05-04-2008, 01:37 AM

He is probably running the Electromotive Ignition system.

http://www.distributorless.com/

Ray Menard · 05-05-2008, 01:29 PM

Thanks guys,

I'd like to stick with a distributor ignition system, just change from 1 coil to 8 coils. Will this require some type of software changes to my MSD Digital 7 box? How will it know how to sequence the spark from the relevant coil?

Thanks

05-03-2008, 08:31 PM	#1
Ray Menard Junior Member Join Date: Aug 2004 Location: Scottsdale, AZ Posts: 49 Likes: 0 Liked 0 Times in 0 Posts	Multiple coils I saw a racer I respect very much a few weeks ago with 8 coils on his Super Stock motor. The more I think about it, the more I wonder if this might be something worth investigating. With a Super Stock motor that sees close to 10,000 RPM in the lights, logic tells me with 8 coils (one/cylinder), each coil would only have to produce a spark 1 out of 8 times instead of 8 out of 8. This time lag, although short (at 10,000 RPM, each plug in an 8 cylinder motor fires 10 times/second). If each coil had to produce only 10 ignition events/second instead of 80 ignition events/second, surely each coil would have more time to recover between events and thus produce a better quality spark. Does this train of thought make any sense or do I need therapy? Does anyone have any experience running multiple coils on a Super Stock motor? __________________ Ray Menard SS/CS (SS/DM & SS/EM) #7386

05-03-2008, 10:13 PM	#2
G Schenck Senior Member Join Date: Mar 2007 Location: Harahan, La. Posts: 521 Likes: 41 Liked 81 Times in 35 Posts	Re: Multiple coils I can't remember that far back but a SS racer that lived in Louisiana had that setup in the early eighties. Made sense to me. Larry Meaux might know , the racer lived near that area , I believe. Greg

05-04-2008, 12:53 AM	#3
Kile Junior Member Join Date: May 2006 Location: Down South Posts: 5 Likes: 0 Liked 0 Times in 0 Posts	Re: Multiple coils Not a /SS car but the Accufab BB/AT, sometimes AA/AT of John Mihovetz is running a coil per cylinder on the Ford mod motor.

05-04-2008, 12:59 AM	#4
Jeff Lee VIP Member Join Date: Jul 2007 Location: Anthem, Arizona Posts: 2,766 Likes: 0 Liked 2 Times in 2 Posts	Re: Multiple coils I see a grey area in the rules on this....unless it is a factory "distributorless" ignition. Ray, was it? Under SS rules it says: "any battery powered ignition permitted. Distributorless ignition must retain OEM number of coils" Under SS/GT (and above) it reads: "any battery powered ignition permitted" So if it was a GT or Modified, I would say no problem to anything but a magneto and as many coils as you like. Ray, I think I would pursue it since you have a Modified SS. Under SS, could you have multiple coils only if the engine came equipped with a distributorless ignition as per OEM? Or could you convert from a distributor based ignition to a distributorless ignition and then would you only have allowance for (1) coil if that's the way it came? __________________ Jeff Lee 7494 D/S '70 AMX

05-04-2008, 01:37 AM	#5
SSDiv6 VIP Member Join Date: Feb 2003 Location: Glendale, Arizona Posts: 2,991 Likes: 693 Liked 1,457 Times in 543 Posts	Re: Multiple coils He is probably running the Electromotive Ignition system. http://www.distributorless.com/

05-05-2008, 01:29 PM	#6
Ray Menard Junior Member Join Date: Aug 2004 Location: Scottsdale, AZ Posts: 49 Likes: 0 Liked 0 Times in 0 Posts	Re: Multiple coils Thanks guys, I'd like to stick with a distributor ignition system, just change from 1 coil to 8 coils. Will this require some type of software changes to my MSD Digital 7 box? How will it know how to sequence the spark from the relevant coil? Thanks __________________ Ray Menard SS/CS (SS/DM & SS/EM) #7386