MX-3.com

Would it work to modify the distributor to just run 12 volts and trigger wires to each coil on plug? I could make a custom cap.

I can't see why not... Not a bad idea.

Isn't that what a distributor cap is already? I don't get it....

Instead of using a disty coil... He'd be triggering a 12v signal to his coil on plug setup, using the disty cam gear to trigger the individual coils.

In theory, it sounds great to me! Honestly, I know very little about electronics though.

the theory makes sense and it'd be freakin cool if you figured out how to do it

It would be very easy to do with a 2 wire coil set up... The problem is in the design of the ignitor... Its designed to drive 1 coil.. Not 6 at a time.. You would over load the ignitor with current...

You could do it with a 3 wire coil set up easier so long as the ignitor is intergrated into the coil.. Then having your factory ignitor driving 6 coils wont over load it with current...

Using the stock pcm and stock ignitor to do this the only gain is no more cap and rotor... The reason for running coil on plug is to get better coil saturation and better spark especially at higher rpms... You wont be changing that since all 6 coils would be firing all the time at the same time... You also still need your distributor for cam position and crank position signals...

You would need something that would sequentially fire and control the coils

I don't think a 12volt signal would travel through the disty cap. It would essentially need to jump the gap between the rotor and the cap wouldn't it? I was thinking, why not use two coils in parallel with the stock system to prevent spark degradation at high rpms. I admit I've had a rough day, brains not working any more and my 7yo daughter has been on my case for the last hour so take this with a grain of salt. lol I think if your not boosting your engine then coil packs are of no benifit. IMO On that note, Jesse have you ever been to see if you have sleep apnea? Ideas like this only come about while being wide awake at 4 in the morning.

Daninski wrote:I don't think a 12volt signal would travel through the disty cap. It would essentially need to jump the gap between the rotor and the cap wouldn't it? I was thinking, why not use two coils in parallel with the stock system to prevent spark degradation at high rpms. I admit I've had a rough day, brains not working any more and my 7yo daughter has been on my case for the last hour so take this with a grain of salt. lol I think if your not boosting your engine then coil packs are of no benifit. IMO On that note, Jesse have you ever been to see if you have sleep apnea? Ideas like this only come about while being wide awake at 4 in the morning.

haha Dan I know what thats like... my 5 year old can be just as bad.. I am sure when you rethink it all you'll see that you don't drive anything threw the cap and rotor... You would either be using the stock ignition control module or the stock ignition control signal..

The problem with using the stock control module to drive 6 coils is to much current load, you would burn the module out..

3 wire coils have an internal control module.. This way you could use either the ignition control signal or the stock control module to fire the coils...

The problem with doing all this is you can only fire all 6 coils at the same time... Do get around that you need something like megasquirt to control the coils and have the fire sequentially..

If you are having spark problems at higher rpms you need to know why... There are 2 main reasons in my opinion to go to a coil on plug system.. 1) to eliminate the distributor cap and rotor.. This will allow for better spark timing control... 2) to create a stronger spark by giving you more time between firing events to get better coil saturation at high rpms...

Coil saturation is control by the computer no the distributor..

If you are having high rpm spark problems with our cars you have 2 options.. 1) HEI mod with a higher out put coil... 2) adjusting spark plug gap..

Jesse has MegaSquirt though

MrMazda92 wrote:Jesse has MegaSquirt though

Yeah I found out about that talking to him at the meet this weekend... Having megasquirt is a different ball game.. Depending on your version you can modify it to run a COP system properly...

I have MegaSquirt too, but I'm waiting to source a good KLG4 to even install it... I have the vacuum line prepped and in position, but I want to get it all done in one go. I know it'll possibly make it hard to diagnose problems that pop up, but it'll help me to shorten the time span that I'm car-less during the swap.

This idea was to just send 12v in, and with a modified cap that wouldn't have the gaps, and have that 12v be distributed to 12v wires that would trigger the COPs.
I actually went back to the sleep doctors, and although I have apnea, it's not bad enough for my insurance to get me turbo to force air in
You don't really mind my crazy ideas, I know this I was thinking it could work for people without a stand alone EMS.

A coil pack has a constant 12v source and a separate ground and trigger wire. The miata guys have
figured out how to have a COP conversion on thier stock setups using wasted spark. For our rpm range
the wasted spark setup provides more than ample charge/dwell time. IIRC miata turbo forums have the
1.6 B6 and 1.8 BP wiring setups on their site. There is a buttload of good info on miata turbo that applies
to B6/BP engines.

Don't use the distributor as a power source for COPs - just use it as a glorified cam angle sensor. Also
buy good Toyota/Denso oem COPs if you are spending the money. No name ones burn out fast.

Oh linky: http://miataturbo.wikidot.com/cop

Thanks