M&W Ignitions Multi-Channel CDI

Tom_in_NH · 10-12-2021, 01:33 PM

Any experience in the collective with M&W, specifically the 6-channel device? They look interesting from the standpoint of a CDI ignition combined with coil packs, and integration with a stand alone ECU. Specifically their Pro-16 model.

For now, it looks as though they only offer single tower coils, which would make my twin plug application cumbersome at best.

I have an email into them asking about twin tower coils (waste spark) availability, or at least a recommendation.

Peter M · 10-12-2021, 02:22 PM

Tom,
Recent discussion on this has sparked (sorry!) my interest in how a distributorless CDI installation would cost and how practical it would be in the limited space available, particularly running twin plugs like you say.

I notice on their website a reference to CDI compatible CoP's. This would make it very easy but I wasn't able to locate a source of new units.

Look forward to hearing what recommendation you receive back.

Arlo911 · 10-12-2021, 09:35 PM

You might want to check with Neil Harvey from Performance Developments, He mentioned M&W in one of the engine build threads.

winders · 10-12-2021, 09:48 PM

I would contact Mission Ignition Systems (https://www.missionignitionsystems.com). They are state of the art as they make ignition systems fro NASA and military rockets as well as for race cars and street cars.

Yes, Mission sells inductive ignition setups only. Why? Because their inductive setups made more power on any engine (including NASA and military rockets) than any CDI system they tested, including their own....

Peter M · 10-12-2021, 11:07 PM

Interesting. Hard to separate out the BS from the facts

A potential source of a CDI compatible CoP though.

mysocal911 · 10-13-2021, 08:43 AM

Quote:

Originally Posted by winders

Yes, Mission sells inductive ignition setups only. Why? Because their inductive setups made more power on any engine (including NASA and military rockets) than any CDI system they tested, including their own....

Furthermore, a CDI system becomes overly complex, costly, and less reliable for a COP system.

trond · trond's Garage

i got a M&W CDI system on Neil Harveys advice and I believe it is good. No issues with the install and would not call it complex. At least not in any way that affects me. 2 CDIs, 2 coils, MS2 and VR sensor with spark distributed through 12 point distributor. I considered two 6 channel CDIs (M&W) for 12 plugs and waste spark but the number of coils was too much to relate to. Apart for the number of coils needed I would have gone that way.

mysocal911 · 10-13-2021, 09:28 AM

Quote:

Originally Posted by trond

i got a M&W CDI system on Neil Harveys advice and I believe it is good. No issues with the install and would not call it complex. At least not in any way that affects me. 2 CDIs and a 12 point distributor.

So, the same approach was used for twin plugged 911 engines for the last 50 years!
But it's not a COP system, which was the key point.

trond · trond's Garage

no it is not a COP. CDI and COP, is that even available ? Much as I like the looks of that distributor and how the engine compartment now is full of cables I would have been interested in not having rotor phasing to think of. Not that it is limiting very much. Just another thing to consider is all

winders · 10-13-2021, 10:32 AM

Here is twin plug CoP inductive.....370 HP at the wheels from a 3.6L:

David · David's Garage

I use a M&W 4 channel CDI controlled by a Motec ECU on my 930. I don't have a 6 channel because they didn't make one when I installed it many years ago. M&W is very high quality with the only drawback being price.

Honestly, I'm surprised more people don't use a single channel M&W CDI on their 911.

David · David's Garage

You mentioned coils too so here's a pick showing the 6 waste spark M&W coils.

Tom_in_NH · 10-14-2021, 09:08 AM

David,

That's interesting to see M&W twin tower waste spark coils. I emailed Wayne at M&W a few days ago specifically requesting those, as they are not listed on their site. How old is this build? His response indicated that they are not available from them, and he went on to recommend a Bosch Motorsport twin tower that is actually two separate coils driven from a single channel. This would then hark back to another raging debate on this forum regarding driving two coils from a single CDI channel. Ugh. As far as I can see, and from Wayne's responses to me, the only option from M&W would be two of the 6 channel CDI's, driving 12 of their single tower coils!

A true waste spark twin tower coil is a single coil, with each of the two spark plugs fired from opposite ends of the secondary coil winding.

I think I'm in Scott Winders camp at this point. Inductive........

David · David's Garage

The build was at least 12 years ago. I wonder why they quit selling them?

As far as driving 2 coils off each channel, I’ve had no issue. I have pretty good sized twisted wires.

winders · 10-14-2021, 08:30 PM

Quote:

Originally Posted by David

As far as driving 2 coils off each channel, I’ve had no issue. I have pretty good sized twisted wires.

That's not the issue. The issue is you are halving the power to the coil...

David · David's Garage

Well, I’m making 475 hp at the wheels at .95 bar so not too bad. One of these days I’ll put a 6-channel CDI on it but there wasn’t one available when I built the engine.

winders · 10-15-2021, 03:31 AM

Ok. It may be perfectly fine to run that way. Which M&W ignition unit are you using? Do they support running two coils on a single channel?

David · David's Garage

It's a Pro-14 CDI. I'm not advocating using a 4-channel now since obviously a 6-channel is better and available but at the time there wasn't much else in a quality CDI. I did work with folks way more knowledgeable than myself to spec out the system and they felt it would work fine.

With that said, I don't see any issue driving 12 coils off a 6-channel CDI because you can wire it so that 1 coil is firing on a power stroke and the other coil is firing on an exhaust stroke. I would not wire two coils off one channel to one cylinder.

rdimarco · rdimarco's Garage

The Bosch twin coil 0221503035 recommended by Wayne at M&W has 2 separate coils in a single housing. Each coil is fired independently so they can be wired to two Pro16b units for twin plug applications. One Pro16b fires the upper plugs and the second Pro16b fires the lower plugs. Each plug has it's own coil and CDI channel, not wasted spark with this arrangement. The twin coil is not a CDI specific coil, but will work and makes a do-able coil-near-plug install if you choose to go CDI without a distributor. Wayne did not recommend any of the pencil coils for use with their multichannel units.

winders · 10-15-2021, 07:19 AM

Quote:

Originally Posted by David

It's a Pro-14 CDI. I'm not advocating using a 4-channel now since obviously a 6-channel is better and available but at the time there wasn't much else in a quality CDI. I did work with folks way more knowledgeable than myself to spec out the system and they felt it would work fine.

With that said, I don't see any issue driving 12 coils off a 6-channel CDI because you can wire it so that 1 coil is firing on a power stroke and the other coil is firing on an exhaust stroke. I would not wire two coils off one channel to one cylinder.

It’s still putting out half the power to the coils so I don’t see how that makes any difference.