Replacement CDI Unit

[mysocal911]

My friend recently purchased a replacement CDI on his '73, which had a PermaTune CDI.
He had to buy a Bosch core, as the company (P....K......) uses the Bosch castings for their
electronics. Has anyone used that CDI and compared it to a Bosch or MSD? Maybe one of the
other CDI suppliers or those that have designed CDIs could comment on the physical design,
layout, and part types used.

Here are images of it:

[Jonny H]

I can offer a similar view of our CDI+ internals:





There is no shortcut to delivering robust and reliable electronics. It is a time consuming and expensive process.

People are sometimes quick to criticise the price of CDI+ but you are paying for:

1) 1000+ Hours of design time.
2) 1 year of road and race trials before launch.
3) Dyno and engine cell testing.
4) $10,000 on CE/FCC Test and Approvals.
5) First class and rapid technical support.
6) Continual improvements. E.g. features added via firmware updates.

Classic Retrofit CDI+

[Indescikov]

What are the three additional wires (yellow, red, blue) used for?

[Jonny H]

Originally Posted by Indescikov

What are the three additional wires (yellow, red, purple) used for?

Red/black - shift light output
Yellow/black - launch / flat shift limiter input
Purple/black - calibrated tacho output.

The calibrated tacho output can be used to trim out the indicated readings. Also, A 10k tacho can be made from a cheap SC tacho with a face swap, without need to send it off.

The detail is all in the PDF manual in the 'Downloads' section here 911 CDI+ (3 Pin) - Classic Retrofit

[911T70]

Nice, tidy design, Jonny! I've done a lot of circuit design and PCB layout in my career and I'm impressed by your work. I'm curious - what is the purpose of the clear tube? Also, will your board fit in a Bosch CDI box? I'm also considering modernizing the CDI circuitry in my 1970 911T, even if it seems to work just fine at the moment. I'm truly impressed that 47 year old electronics just keeps putting out all that energy!

[mysocal911]

Originally Posted by Jonny H

I can offer a similar view of our CDI+ internals:





There is no shortcut to delivering robust and reliable electronics. It is a time consuming and expensive process.

People are sometimes quick to criticise the price of CDI+ but you are paying for:

1) 1000+ Hours of design time.
2) 1 year of road and race trials before launch.
3) Dyno and engine cell testing.
4) $10,000 on CE/FCC Test and Approvals.
5) First class and rapid technical support.
6) Continual improvements. E.g. features added via firmware updates.

Classic Retrofit CDI+

You haven't posted an image of the backside of your unit's circuit board? No comments
on my friend's CDI unit and the components being used, component mounting, and the layout?

[Jonny H]

Originally Posted by mysocal911

You haven't posted an image of the backside of your unit's circuit board? No comments
on my friend's CDI unit and the components being used, component mounting, and the layout?

To post comments about another company's design on a public forum 'just isn't cricket'.

I won't post pictures of the other side of our board either, IPR and all that. I can tell you it is just as tidy as the topside.

I am happy to answer questions about our design.


911T70,

The plastic 'tube' is a light pipe that transmits the status led to the top of the case. The led is used to indicate distributor trigger input and also the 4 special modes for setting rev limiters using the in car tacho as a display. See the manual for 'jogwheel functions'.

Yes, our board does fit in the standard Bosch case and we will shortly be offering a CDI+ update service for the USA through Pelican!

[mysocal911]

Originally Posted by Jonny H

I won't post pictures of the other side of our board either, IPR and all that. I can tell you it is just as tidy as the topside.

Most likely someone will obtain one of your units and then technically analyze it with images of both sides
of the circuit board & other internals over time. We'll have to wait.

[Jonny H]

Originally Posted by mysocal911

Most likely someone will obtain one of your units and then technically analyze it with images of both sides
of the circuit board & other internals over time. We'll have to wait.

Maybe, but most folks just put them on their cars and enjoy.

[mysocal911]

Originally Posted by mysocal911

Most likely someone will obtain one of your units and then technically analyze it with images of both sides
of the circuit board & other internals over time. We'll have to wait.

A closer look at your unit indicates that your CDI, as is the case for the other unit, uses an electrolytic
capacitor in the harsh temperature environment of a 911's engine compartment, especially in
a 911 Turbo. As you mostly likely know, electrolytic capacitors have a high fail rate especially
in high temp environments.

[Neil Harvey]

As important as looks should also be the function.

Performance Developments has used and sold the M&W product for over 20 years and recently we have added the Classic Retrofit product to our product line.

The products we sell are products we use in our own engine projects. They have to meet our high level of quality and performance. The classic retrofit unit meets everyone and more.

The Classic Retrofit CDI unit offers several features that are unavailable in other CDI units, that make this unit stand out from the rest.

[Neil Harvey]

As a user of CDI ignition systems for these Porsche engines, in all the years we have been in business building engines, we have never found a Bosch CDI or any aftermarket repaired or modified unit to perform anywhere close to the M&W and now the Classic unit.

As a engine provider we rely upon external systems like Ignition CDI unit components to perform. An engine is useless without these critical components doing the job we expect them to do. Our reputation is at stake and we place this squarely in the hands of companies that provide these critical components. This is why we are careful of what we use and sell.

We have tested just about every CDI on the market over the years and have never had one of the repaired or modified Bosch units out perform or come close to the M&W unit and now the Classic unit.

[911T70]

[QUOTE=mysocal911;9766275]My friend recently purchased a replacement CDI on his '73, which had a PermaTune CDI.
He had to buy a Bosch core, as the company (P....K......) uses the Bosch castings for their
electronics. Has anyone used that CDI and compared it to a Bosch or MSD? Maybe one of the
other CDI suppliers or those that have designed CDIs could comment on the physical design,
layout, and part types used.

I am surprised by how few components there are. That's usually a good thing - simple=better and it reduces the odds of failure. I've been researching CDI alternatives to my original unit and everything I've read about P....K...... has been very positive.

[911T70]

Originally Posted by Neil Harvey

As a user of CDI ignition systems for these Porsche engines, in all the years we have been in business building engines, we have never found a Bosch CDI or any aftermarket repaired or modified unit to perform anywhere close to the M&W and now the Classic unit.

As a engine provider we rely upon external systems like Ignition CDI unit components to perform. An engine is useless without these critical components doing the job we expect them to do. Our reputation is at stake and we place this squarely in the hands of companies that provide these critical components. This is why we are careful of what we use and sell.

We have tested just about every CDI on the market over the years and have never had one of the repaired or modified Bosch units out perform or come close to the M&W unit and now the Classic unit.

I just re-read all the posts on this thread and can't figure out what M&W is. Did I miss something?

[911T70]

Originally Posted by Jonny H

To post comments about another company's design on a public forum 'just isn't cricket'.

I won't post pictures of the other side of our board either, IPR and all that. I can tell you it is just as tidy as the topside.

I am happy to answer questions about our design.


911T70,

The plastic 'tube' is a light pipe that transmits the status led to the top of the case. The led is used to indicate distributor trigger input and also the 4 special modes for setting rev limiters using the in car tacho as a display. See the manual for 'jogwheel functions'.

Yes, our board does fit in the standard Bosch case and we will shortly be offering a CDI+ update service for the USA through Pelican!

Does this mean you can sell the internals only, to be fitted by the costumer in their original Bosch boxes? I'd be very interested if this was the case!

[Jonny H]

Originally Posted by 911T70

Does this mean you can sell the internals only, to be fitted by the costumer in their original Bosch boxes? I'd be very interested if this was the case!

We can't do that for DIY unfortunately, the liability is too great. Remember, this is a high voltage DC power supply, quite capable of causing serious electric shock, possibly even death.

[Jonny H]

Originally Posted by mysocal911

A closer look at your unit indicates that your CDI, as is the case for the other unit, uses an electrolytic
capacitor in the harsh temperature environment of a 911's engine compartment, especially in
a 911 Turbo. As you mostly likely know, electrolytic capacitors have a high fail rate especially
in high temp environments.

That capacitor is rated 125 deg C and recommended for automotive applications.

Next issue is vibration. That's why all our components are low profile SMT.

[mysocal911]

Originally Posted by Jonny H

That capacitor is rated 125 deg C and recommended for automotive applications.

Next issue is vibration. That's why all our components are low profile SMT.

Would you consider that those two design issues as key in any automotive system and especially
critical when that system is in the engine compartment? Given that, have you observed any aftermarket
replacement CDIs that lack compliance to those design issues recently, i.e. given that I would assume
you evaluate competitive products? And do you think that Bosch adhered to those design constraints
with their 911 CDI units? If not, where in their design?

You haven't shown how the under side (image) of your product complies with the above.

[rwest]

Originally Posted by mysocal911

Would you consider that those two design issues as key in any automotive system and especially
critical when that system is in the engine compartment? Given that, have you observed any aftermarket
replacement CDIs that lack compliance to those design issues recently, i.e. given that I would assume
you evaluate competitive products? And do you think that Bosch adhered to those design constraints
with their 911 CDI units? If not, where in their design?

Dave,

You seem to have a lot knowledge of the CDI design and frequently post on these type of threads, would you please be kind enough to list your education, degrees, certifications etc.?

Most importantly, do you have any business or financial connections to any companies or do you profit from the design, manufacturing, sales or repair of ignition devices?

Thanks

[Helix8]

I would like to know why mysocal911 always seems to hijack threads as soon as Jonny H posts information which may be useful to OP's question? I for one appreciate an uncluttered thread -'kindly stay on topic.