Is anyone running coil on plug?
10-07-2005, 01:35 AM
#2
Jane Bond 007
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Not yet, but it's on the front burner for a Fall/Winter project. I've got the coils in the carriage house, I'll post pics tomorrow.
10-07-2005, 09:31 AM
#4
Three Wheelin'
10-07-2005, 03:57 PM
#6
Three Wheelin'
Stock cap/rotor distributed ignition:
one coil for four cylinders
one spark per 2 crank revolutions (per cylinder)
primary wire
4 plug wires
DIS (distributorless ignition system):
two coils for four cylinders
two sparks per 2 crank revolutions (per cylinder) (called "wasted spark")
no primary wire
4 plug wires
COP (coil on plug):
4 coils for four cylinders
1 spark per 2 crank revolutions ("true" COP, can also do wasted spark)
no primary wire
no plug wires (coil connects directly to plug)
Advantages as you go from stock to DIS to COP include greater spark energy and the ability to run higher RPMs. In our case, RPMs are limited by the valvetrain, and the stock system has plenty of time to fire off twice per crank revolution, even at 7k rpms or more. Judging from some hi-po 951s in the past, the cap/rotor combo is also capable of handling double stock hp levels or more, but they might have used a hotter coil, I don't know.
The other advantages include eliminating the electro-mechanical wear/failure prone cap and rotor. DIS coils will last a long time.
COP is more of a "bling thing", it shouldn't give significantly more performance than you could get out of a good DIS coil like the GM LS2 coils. But the idea of getting rid of plug wires entirely and having that much cleaner of an engine bay is both asthetically pleasing and possibly four less thing that can fail.
I'm looking at COP coils mainly because I can with the Megasquirt EMS I'll be running. The stock ignition system won't run either COP or a pair of plain old DIS coilpacks, unless you get a little magical reworking from Vitesse.
one coil for four cylinders
one spark per 2 crank revolutions (per cylinder)
primary wire
4 plug wires
DIS (distributorless ignition system):
two coils for four cylinders
two sparks per 2 crank revolutions (per cylinder) (called "wasted spark")
no primary wire
4 plug wires
COP (coil on plug):
4 coils for four cylinders
1 spark per 2 crank revolutions ("true" COP, can also do wasted spark)
no primary wire
no plug wires (coil connects directly to plug)
Advantages as you go from stock to DIS to COP include greater spark energy and the ability to run higher RPMs. In our case, RPMs are limited by the valvetrain, and the stock system has plenty of time to fire off twice per crank revolution, even at 7k rpms or more. Judging from some hi-po 951s in the past, the cap/rotor combo is also capable of handling double stock hp levels or more, but they might have used a hotter coil, I don't know.
The other advantages include eliminating the electro-mechanical wear/failure prone cap and rotor. DIS coils will last a long time.
COP is more of a "bling thing", it shouldn't give significantly more performance than you could get out of a good DIS coil like the GM LS2 coils. But the idea of getting rid of plug wires entirely and having that much cleaner of an engine bay is both asthetically pleasing and possibly four less thing that can fail.
I'm looking at COP coils mainly because I can with the Megasquirt EMS I'll be running. The stock ignition system won't run either COP or a pair of plain old DIS coilpacks, unless you get a little magical reworking from Vitesse.
10-08-2005, 05:21 PM
#7
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Originally Posted by DanG
Advantages as you go from stock to DIS to COP include greater spark energy and the ability to run higher RPMs. In our case, RPMs are limited by the valvetrain, and the stock system has plenty of time to fire off twice per crank revolution, even at 7k rpms or more. Judging from some hi-po 951s in the past, the cap/rotor combo is also capable of handling double stock hp levels or more, but they might have used a hotter coil, I don't know.
The other advantages include eliminating the electro-mechanical wear/failure prone cap and rotor. DIS coils will last a long time.
COP is more of a "bling thing", it shouldn't give significantly more performance than you could get out of a good DIS coil like the GM LS2 coils. But the idea of getting rid of plug wires entirely and having that much cleaner of an engine bay is both asthetically pleasing and possibly four less thing that can fail.
I'm looking at COP coils mainly because I can with the Megasquirt EMS I'll be running. The stock ignition system won't run either COP or a pair of plain old DIS coilpacks, unless you get a little magical reworking from Vitesse.
The other advantages include eliminating the electro-mechanical wear/failure prone cap and rotor. DIS coils will last a long time.
COP is more of a "bling thing", it shouldn't give significantly more performance than you could get out of a good DIS coil like the GM LS2 coils. But the idea of getting rid of plug wires entirely and having that much cleaner of an engine bay is both asthetically pleasing and possibly four less thing that can fail.
I'm looking at COP coils mainly because I can with the Megasquirt EMS I'll be running. The stock ignition system won't run either COP or a pair of plain old DIS coilpacks, unless you get a little magical reworking from Vitesse.
Geoff
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10-08-2005, 08:06 PM
#10
Three Wheelin'
Right you are Geoff. We'll get to test that out on the briggs soon enough. I'm not sure what the motronic is capable of spark table wise with re-worked code. John, will you have 8x8 or 12x12 or some other spark tables?.
10-08-2005, 08:21 PM
#11
Campeck Rulez
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on the briggs. lol
are you sure testing a lawnmower engine is good grounds to then use on a car.
whats the compression on that thing? and whats the head layout?
just wondering.
are you sure testing a lawnmower engine is good grounds to then use on a car.
whats the compression on that thing? and whats the head layout?
just wondering.
10-09-2005, 03:45 AM
#12
Three Wheelin'
Its not like I'm going to use the VE or spark tables from the Briggs on my 951. I'll just use it to test out all the nifty functions of the EMS.
And its a generator engine, not a lawnmower one.
http://www.perkart.com/vtwin.htm
Compression is about 9 or 10:1? Stock is 8.3:1. I'm not quite sure as our engine is a "hi-po" built version from a race builder and I didn't order it. Its either bored and/or stroked from 570cc to 590cc, and has bigger Ti valves, roller rockers, stiffer springs, and maybe a few other tricks. I'm going to have to get a solid answer as to what it has and what its specs are before slapping the turbo on it.
And its a generator engine, not a lawnmower one.
http://www.perkart.com/vtwin.htm
Compression is about 9 or 10:1? Stock is 8.3:1. I'm not quite sure as our engine is a "hi-po" built version from a race builder and I didn't order it. Its either bored and/or stroked from 570cc to 590cc, and has bigger Ti valves, roller rockers, stiffer springs, and maybe a few other tricks. I'm going to have to get a solid answer as to what it has and what its specs are before slapping the turbo on it.
10-09-2005, 07:05 AM
#13
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Originally Posted by geoffct
You neglected to mention the other significant benefits of being able to setup a timing/advance map and spark energy map. Yes bling, but only relatively to DIS.
Geoff
Geoff
Doesn't all ignition systems have ignition advance maps and adjustable coil charge time / dwell angle? At least the Motronic does.
11-15-2005, 06:02 PM
#14
Three Wheelin'
COP here I come. I just bought these puppies off ebay...
They're from a CBR F4i. I've been told (by geoffct above, also known as the guy that helps MichelleJD with her engine work) that they fit into the 951 head perfectly. The other plus is they have internal current limiting/dwell control, so they'll be easier to configure.
Update on the briggs project. Its running beautifully now. I've decided to just do Coil-Near-Plug on it since a 5-6" long COP unit would look silly hanging out the side of the engine. BTW, its 10:1 compression. Here's a short vid of it running last night...
http://evilallianceracing.com/ipw-we...quirt/MVI_2740
More details on it here...
http://www.msefi.com/viewtopic.php?t=13081
They're from a CBR F4i. I've been told (by geoffct above, also known as the guy that helps MichelleJD with her engine work) that they fit into the 951 head perfectly. The other plus is they have internal current limiting/dwell control, so they'll be easier to configure.
Update on the briggs project. Its running beautifully now. I've decided to just do Coil-Near-Plug on it since a 5-6" long COP unit would look silly hanging out the side of the engine. BTW, its 10:1 compression. Here's a short vid of it running last night...
http://evilallianceracing.com/ipw-we...quirt/MVI_2740
More details on it here...
http://www.msefi.com/viewtopic.php?t=13081
11-23-2005, 03:09 AM
#15
Three Wheelin'
Booya!
http://evilallianceracing.com/ipw-web/gallery/951COP
So they fit. They're a tad long, I'm not sold on it being robust enough for lots of miles yet. But man, it looks sweet!
http://evilallianceracing.com/ipw-web/gallery/951COP
So they fit. They're a tad long, I'm not sold on it being robust enough for lots of miles yet. But man, it looks sweet!