Twin Spark Firing using single CDI Box

[Mark Henry]

Originally Posted by Fred Winterburn

Jonny, You need to buy an old MSD 6A and test it (no longer made from what I hear).

Correct but IIRC the MSD 6TN/6ALN NASCAR CD Ignitions 6430 is basically a 6AL, just 2.5-3X the money.

[Henry Schmidt]

Originally Posted by Mark Henry

Correct but IIRC the MSD 6TN/6ALN NASCAR CD Ignitions 6430 is basically a 6AL, just 2.5-3X the money.

The exception was a clear base plate so the box could be visually inspected. MSD claims 'Extreme duty" whatever that means.

[dannobee]

I think the internal potting was also clear, so that the electronics could be inspected and/or offer protection from tampering. Previously the potting was black and could not be easily inspected for the aforementioned traction control by the tech officials. The potting "also" offered "vibration protection."

[Henry Schmidt]

Originally Posted by dannobee

Nascar Cup cars quit using MSD boxes when the R07 engine came out (2011?) At least that was when it was in testing.
The biggest problem with MSD boxes in the pro categories was that some (most?) teams were adding traction control internally and nascar couldn't police it effectively. Mclaren/Freescale ECU's are effectively anti tamper proof, where any modifications are traceable and detectable at the track. The MSD boxes were routinely sent back to MSD to look for any modifications. That took days.
The way that the traction control worked was in conjunction with the rev limiting software. If the engine rpm climbed above a certain rate, the ignition timing was retarded. There were no wheel speed/driveshaft speed, car speed sensors needed, only the engine speed input. And obviously the ignition box needed to see that. We all pointed fingers at each other and it all seemed to get swept under the rug with nobody ever getting "busted" for it. Until EFI and the Mclaren ECU's came out and leveled the playing field.

"The biggest problem with MSD boxes in the pro categories was that some (most?) teams were adding traction control internally"
This sounds interesting. Do you know if it's possible to use the input for the rev limiter chip to create a similar effect (IE: traction control)?

[dannobee]

The outlaw traction control was done through the circuitry designed for the rev limiter chip, inside the box, so as not to be easily detected. Davis Technologies has a box that plugs in place of the rev limiter chip, but I think MSD must have learned a lot from the confiscated boxes too, because I see that they now sell traction control on the Holley website. I have no idea what other devices it takes to make theirs work though.

https://moretraction.com/

Davis's prices are crazy high for traction control though. If you're not racing with it, you could get similar traction control for a lot less. Even some of the aftermarket EFI ECU's come with it now.

[Focker]

Originally Posted by Henry Schmidt

"The biggest problem with MSD boxes in the pro categories was that some (most?) teams were adding traction control internally"
This sounds interesting. Do you know if it's possible to use the input for the rev limiter chip to create a similar effect (IE: traction control)?

The Jordan Suzuki and Yoshimura Suzuki team were doing this back in 2007 when TC wasn't allowed. Effectively they use rate of change software and start to cut the ignition. This was done WITHOUT wheel speed sensors.

I had the add-on traction control on my racebike that was programable for sensitivity. Not sure if that actually answers the question, but once the genie was out of the bottle, they had to lift the ban.

TC now is unbelievably complex in MotoGP, even with the standard ECU. Throttle and ignition mapping is custom tailored per gear and per corner and based on lean angle. GPS was outlawed, but with the start/finish timing loop, the bike does know where it is on track.

[Focker]

Originally Posted by dannobee

The outlaw traction control was done through the circuitry designed for the rev limiter chip, inside the box, so as not to be easily detected. Davis Technologies has a box that plugs in place of the rev limiter chip, but I think MSD must have learned a lot from the confiscated boxes too, because I see that they now sell traction control on the Holley website. I have no idea what other devices it takes to make theirs work though.

https://moretraction.com/

Davis's prices are crazy high for traction control though. If you're not racing with it, you could get similar traction control for a lot less. Even some of the aftermarket EFI ECU's come with it now.

It cost me less than $1,000 for piggyback ECU, wiring harness, ignition module, quick shifter, traction control and self mapping with O2 sensor for a motorcycle. that's running 4 COP and 8 injectors. I can't understand why the Davis stuff is so expensive.

[Henry Schmidt]

New prototype Duel CD coming soon. Designed and manufactured in the USA.
Testing is on going and limited manufacturing is happening.... Now!

One CD triggering two coils. The box is small (5"x6"x2") and designed to be Porsche specific. All wiring color coding is familiar to anyone who works on the air-cooled engines.

[Neil Harvey]

May I throw my hat in the ring now too.

Great more are becoming available for the market to choose from. What I am pleased about is this new one is also CDI.

I have been selling CDI Ignition for years from these large hemi chamber engines and found in our own testing, that these engines start easier, run better and make more torque with CDI. We have tested about every other Inductive system available and found nothing that comes close.

Maybe others have found the opposite result, as I see many engines running Inductive Ignition. I often think its all about simplicity and cost. The engine runs and make power so why the need for CDI? Its in our name, Performance Developments!

We have been selling this system for years that drives two coils simultaneously. This is well proven, we have been selling this product and the other options for over 25+ years without any failures.

Check out M&W Pro 14 dual coil for Porsche. We make up a simple small adapter harness that plugs right into the stock harness. Single channel system for both Points or reluctor triggered engine are also available.

Keep them coming as more is always better.

[Neil Harvey]

We mate the CDI with its own made for CDI Coils.

[Jeff Alton]

M&W has been producing great products for many years, great choice.

[Henry Schmidt]

Originally Posted by Neil Harvey

We mate the CDI with its own made for CDI Coils.

What could be better?
More options to enhance my twin plug distributors.

[Henry Schmidt]

[Fred Winterburn]

Nice and neat looking. And there is a real call for two channel CDI systems. Looks like something Bob Ashlock might have done. I'm not going to build a two channel unit. If someone wants to fire two coils they will need two boxes. I'm even going to go more retrograde on a handful of units by using some NOS 1963 germanium power transistors that have aged well. But those units won't be going on race cars. Fred

Originally Posted by Henry Schmidt

New prototype Duel CD coming soon. Designed and manufactured in the USA.
Testing is on going and limited manufacturing is happening.... Now!

One CD triggering two coils. The box is small (5"x6"x2") and designed to be Porsche specific. All wiring color coding is familiar to anyone who works on the air-cooled engines.

[Henry Schmidt]

You are correct. Bob is the genius behind this clean little system.
I designed the housing and wiring components to incorporate his electronics into an easy to use, cost effective, high energy system.
Even the wiring codes will be Porsche compatible.
I spoke with M&W ignitions (highly recommended) but elected to work with a small, home grown company nearer to my location.
I like the thought of working with local technicians with the drive and willingness to nibble around the edges.

[Fred Winterburn]

Believe me when I say it was an educated guess that this was Ashlock's work. The simplicity and layout of the board, for the work it has to do was the clue. You've partnered with a good man. Fred

Originally Posted by Henry Schmidt

You are correct. Bob is the genius behind this clean little system.
I designed the housing and wiring components to incorporate his electronics into an easy to use, cost effective, high energy system.
Even the wiring codes will be Porsche compatible.
I spoke with M&W ignitions (highly recommended) but elected to work with a small, home grown company nearer to my location.
I like the thought of working with local technicians with the drive and willingness to nibble around the edges.

[Rosco_NZ]

Originally Posted by Rosco_NZ

It seems to me it should be possible to produce twin HV spark output from a single primary / twin secondary winding coil such as MSD 8224. This coil appears to have suitable primary resistance at 0.35 ohms so as not to overload the CDI box driver output. Each secondary spark would go to the twin distributor HV input terminal and fire each pair of cylinder plugs.

However I am sure I am not the first to think of this, however all vintage 911 twin spark implementations seem to double up on CDI units and 2x single coils. I get there may be some redundancy benefits for racing, but that's not me / many of us. I understand ignition timing could be adjusted independently with 2x CDI boxes, however from my investigations, twin ignitions for performance are fired simultaneously. (And any engine forced to drop to single plug with only 26 deg. advance will be very sluggish)

I am thinking this can only be the vintage crowd staying traditional ... any other good reasons????

For anyone interested, I did end up installing twin CDI boxes into my build .. rubber mounted Daytona Sensors CD-1.

[Rosco_NZ]

But I have yet to install a Twin Plug distributor. If anyone knows of spare JB Racing distributor, love to hear from you.

[H-viken]

Originally Posted by Rosco_NZ

But I have yet to install a Twin Plug distributor. If anyone knows of spare JB Racing distributor, love to hear from you.

Why not get one from Henry?

[Henry Schmidt]

Here is our new twin CD. Small size [5"X6"], long harness for mounting diversity, state of the art electronics. Custom adjustable rev limiter.
Our distributors are custom built per/application in Bosch or Marelli options.