Pinned Coil On Plug conversions - COP

OK, I am going to be lazy, actually I'm not - here's your primary resistance numbers
https://www.2fiftycc.com/index.php?threads/ok-heres-a-hard-one.8819/#post-90531

OEM coil
Primary
2.5Ω - 3.5Ω
Secondary
12,000Ω) and 18K Ω (18,000 Ω)

What you've got
Primary [the only part which matters as it relates to the current draw when the coils are being charged]
1.6Ω - 1.7Ω primary
Secondary
13K Ω

White man magic resistance calculation for primary resistance when they are used in series is R1 + R2 = 3.2Ω - 3.4Ω

You're pretty much bang on the numbers there champ, the primaries will saturate and NOT overheat due to excessive dwell

I do believe that the resistance of the secondary gives some indication as to the number of turns in that winding, but I'm not sure if it's a strictly linear relationship, but again, 13K Ω is in spec

I say make it go VROOM

 

Not suggesting that you break them or modify them, as the length is no longer an issue anyway, but I am intrigued as to whether or not the rubber boot/toe on the coils is removable &/or replaceable - I don't think it would materially alter the overall length of the C.O.P. - just interested

 

Perhaps add to your profile description
"May contain traces of nuts"

 

I'm now on the ignition upgrade trail. My boosted 250 can't get above 12.5k rpm so wanting to change my ignition out. I made an ignition module using two of these https://au.mouser.com/datasheet/2/308/ISL9V5036P_F085-D-1810286.pdf connecting the MS3X coil logic outputs to the original MC22 coil packs.

If I was to change to COP running in series, would this generate a more powerful spark then the traditional coil setup?

 

I have a Coil Near Plug setup on my bike using coils from something like a LS3 I think. So far I've run it up to about 14,000rpm with a bit of boost and 18,000rpm NA. They're cheap as chips and seem to do the job. I am running a Link ECU to control them. The good thing is that they have builtin drivers so you only need a logic level control input. They have 4 wires - +12v, ground, control signal, & signal ground. I got mine from a performance shop in OZ. The crate motors arrive with the stock coils and they're often swapped out immediately leaving the originals spare, and cheap.

 

Hi mike, I was thinking of this as I can drive ls1/ls2 coils directly. Only thing I was worried about is space to mount them. Certainly would be a simplier setup wiring wise and I know I will get the power. Your 12v supply to the coils, what size wire and fuse are you running, and what about dwell times/dwell tables?

 

The supply wires aren't huge just regular automotive wire from Supercheap, and neither is the fuse. Dwell is 2.1mS across the full rev range at 14V. I think you can also get dual output coils that are very similar. Obviously they fire a waste spark which I don't need and wouldn't do even if all 4 cylinders were there.

 

It seems my coils have the designation D510c

 

Mike,

Ok thanks for that. I got my hands on 8x LS2 coils for 100 bucks so I'll be installing 4 of them and running full sequential fuel and spark. Let see how that goes

 

Bargain. I think they are pretty reasonable coils. Did you get a spec sheet with them? The dwell time is important. Too little and the primary current won't peak and too much and they can overheat. apart from the excess current draw. I was surprised how much the current drawn increased with revs

 

I've been researching that information and of course people use them in cars so the tables only go up to 8000 rpm. A lot of info on the miata forums as they're big on megasquirt (which I'm using) and ls coils.

https://www.miataturbo.net/diy-turbo-discussion-14/lsx-coil-thread-82744/page8/#post1380527
https://www.miataturbo.net/megasqui...park-duration-dwell-battery-correction-86602/

 

The Miata guys have the dwell set high. There's no advantage to doing that. Once peak current is achieved leaving it turned on longer won't increase it any further. The downside is that more current is drawn and a bit of heat in the coils. Even with a bit of boost in the previous engine and not revving properly due to valve float the ignition was never a problem.

 

Update. Ls2 coils are now running on my cbr250rr. Ill do some tuning and if all goes well Ill post some dwell settings.