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How would you get the factory system to work if your distributor is locked out? The only reason to replace the Bosch CDI would be because it failed at some point so the decision to go non-stock the the very slight improvement a modern CDI can give. Maybe worth, it maybe not.

MSD might have some noted failures but compared to the volume I would like to know the percentage of these failures. Since I have not read about constant failures of MSD boxes my injmpression is that it is very small.


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Old 02-28-2018, 06:49 PM
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Originally Posted by Jonny H View Post
I still donít quite understand what the exact requirement is and why the factory system isnít good enough.
Because the factory "system" is not much more than some wonky weights in the distributor. Surely you'd understand that retarding the timing electronically is superior?

I mean, you're in the electronics business, right?
Old 03-01-2018, 05:28 AM
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^^^ I was going to let it go.
I don't even understand how someone who makes a distributor lockout part and designs a programmable ignition system would make that statement.
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Old 03-01-2018, 05:59 AM
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Quote:
Originally Posted by Mocker View Post
Because the factory "system" is not much more than some wonky weights in the distributor. Surely you'd understand that retarding the timing electronically is superior?

I mean, you're in the electronics business, right?
No, the boost retard is controlled by pressure and is a separate mechanism in the distributor.

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Originally Posted by 1979-930 View Post
^^^ I was going to let it go.
I don't even understand how someone who makes a distributor lockout part and designs a programmable ignition system would make that statement.
You both misunderstand what I am asking.

Yes, the CDI+ replaces the main timing curve which is controlled by the weights and springs. You can change the curve to what ever you want with our system.

The Turbo has two further mechanisms controlled by vacuum/pressure. One is to advance the timing for fuel economy cruising. The second is to retard the timing under boost.

My question specifically is what is wrong with the factory boost retard system? My understanding is that it takes off 8 degrees at 1 bar of boost. Is it that you want to control that amount more accurately?
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Last edited by Jonny H; 03-01-2018 at 01:04 PM..
Old 03-01-2018, 01:00 PM
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That's actually a bit of a misconception. It does not have boost retard per se, what it does have is a vacuum advance pot that loses vacuum when you hit boost. The point of going with a programmable system is to get rid of all the weights, pots, etc.

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Originally Posted by Jonny H View Post
No, the boost retard is controlled by pressure and is a separate mechanism in the distributor.



You both misunderstand what I am asking.

Yes, the CDI+ replaces the main timing curve which is controlled by the weights and springs. You can change the curve to what ever you want with our system.

The Turbo has two further mechanisms controlled by vacuum/pressure. One is to advance the timing for fuel economy cruising. The second is to retard the timing under boost.

My question specifically is what is wrong with the factory boost retard system? My understanding is that it takes off 8 degrees at 1 bar of boost. Is it that you want to control that amount more accurately?
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Old 03-01-2018, 01:08 PM
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It does not retard. It only cancels out advance.
So you have a very restricted curve and advance retard system.
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Old 03-01-2018, 01:08 PM
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Originally Posted by dos531 View Post
That's actually a bit of a misconception. It does not have boost retard per se, what it does have is a vacuum advance pot that loses vacuum when you hit boost. The point of going with a programmable system is to get rid of all the weights, pots, etc.
Thanks for clearing that up!

So you want to be able to 'map' boost against retard, right?
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Old 03-01-2018, 01:22 PM
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Quote:
Originally Posted by Jonny H View Post
Thanks for clearing that up!

So you want to be able to 'map' boost against retard, right?
Yeah that would be ideal. There are also other devices like the j&s safeguard that can add boost retard functions.

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Old 03-01-2018, 01:26 PM
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We would like to have a NA timing curve and 32-34* total advance off-boost.
These engine have low compression and a better advance curve will help them RPM quicker and get better fuel mileage when cruising.
But we need to pull timing out accurately and quickly with a MAP on boost to avoid detonation.
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Old 03-01-2018, 01:30 PM
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Originally Posted by 1979-930 View Post
We would like to have a NA timing curve and 32-34* total advance off-boost.
These engine have low compression and a better advance curve will help them RPM quicker and get better fuel mileage when cruising.
But we need to pull timing out accurately and quickly with a MAP on boost to avoid detonation.
Gotcha.

Required range for boost pressure and retard?

Is there already a tap off point/pipe for boost pressure?
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Old 03-01-2018, 01:35 PM
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So often, a question about a part or its use gets lost in the multiple opinions of what is good and what isn’t. What is good is often lost in the extra cost required, the quality is often dismissed, or the lack of quality more often than not, never known or understood.

Let me be clear, MSD is not high-quality merchandise. But, neither is anything else sold at that price point. Never forget, you get what you pay for.

I have formed this opinion and had it proven over and over, from years in the business where high quality was expected and demanded. When buying quality, you are not just buying a high-quality part, you are actually buying a company’s reputation.

Opinions often loose track of the original question too. Many seem to get lost in the reality, often the function or part(s) ability or control, is misunderstood. In this case, overrated.

I read here, some say that you must have a boost retard function, or they would never buy a CDI unit unless it had one. Let’s be clear, the factory boost retard function is better than nothing, as long as it works. But this is where I think the system is overrated.

This is not a detonation sensing system. It retards the timing based upon MAP, by mechanically rotating the distributor base plate with arms and springs. As the manifold pressure increases, the timing is supposedly retarded. The only difference between controlling the timing this way as opposed to having a timing curve do this, is when the engine is put under load, eg, same RPM but going up a hill. (example of added load). The timing curve option would only change with engine speed. The timing would not change if the engine speed was constant, but the engine was put under added load.

But how much added load do these engines see going up hills. Not much, and the retard function is slow, possibly not even working as it should.

Detonation is fast, and the control of this antiqued system is extremely slow. You hope that the MAP and engine speed and this retardation control match the onset of any detonation. Without a sensing device and extremely fast and accurate retard function, any system is a guess, a hope and a prayer at best.

The Classic system gives you the ability to leave the factory system in place and working as best it does now. You get the rev limiter adjustability as well.

It also gives the ability to lock out the distributor and program your own timing curve. For NA engines, this is a great option as the timing can be tailored up to and just back from knock with no MAP issues, as everything is vacuum to atmo based.

I think for turbo engines this is also a workable part. You can easily log the MAP v RPM under normal driving load and create a timing curve just back from knock. You can measure knock easy today with simple knock sensing devices. We sell one that works well that you can adjust out the noise and set your own detonation threshold. Then you can load the engine further and build into the timing curve further safety. I would bet this would be more accurate and net more performance than relying upon the factory mechanical system.

I think many owners over think the ability of the factory system and overrate its ability. The engine last because of low static engine compression numbers and very conservative ignition timing numbers. A lot of the engine capable performance is lost, unfortunately.

Don’t get me wrong, the Classic CDI units are not EFI ECU’s. but when applied correctly will outperform the factory systems all day long. And they are made to a very high standard, lacking in the older factory units, many of the new aftermarket replacements and for sure, well above anything MSD sells.
Old 03-01-2018, 01:52 PM
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Yesssss

Correct !

Quote:
Originally Posted by Neil Harvey View Post
So often, a question about a part or its use gets lost in the multiple opinions of what is good and what isnít. What is good is often lost in the extra cost required, the quality is often dismissed, or the lack of quality more often than not, never known or understood.

Let me be clear, MSD is not high-quality merchandise. But, neither is anything else sold at that price point. Never forget, you get what you pay for.

I have formed this opinion and had it proven over and over, from years in the business where high quality was expected and demanded. When buying quality, you are not just buying a high-quality part, you are actually buying a companyís reputation.

Opinions often loose track of the original question too. Many seem to get lost in the reality, often the function or part(s) ability or control, is misunderstood. In this case, overrated.

I read here, some say that you must have a boost retard function, or they would never buy a CDI unit unless it had one. Letís be clear, the factory boost retard function is better than nothing, as long as it works. But this is where I think the system is overrated.

This is not a detonation sensing system. It retards the timing based upon MAP, by mechanically rotating the distributor base plate with arms and springs. As the manifold pressure increases, the timing is supposedly retarded. The only difference between controlling the timing this way as opposed to having a timing curve do this, is when the engine is put under load, eg, same RPM but going up a hill. (example of added load). The timing curve option would only change with engine speed. The timing would not change if the engine speed was constant, but the engine was put under added load.

But how much added load do these engines see going up hills. Not much, and the retard function is slow, possibly not even working as it should.

Detonation is fast, and the control of this antiqued system is extremely slow. You hope that the MAP and engine speed and this retardation control match the onset of any detonation. Without a sensing device and extremely fast and accurate retard function, any system is a guess, a hope and a prayer at best.

The Classic system gives you the ability to leave the factory system in place and working as best it does now. You get the rev limiter adjustability as well.

It also gives the ability to lock out the distributor and program your own timing curve. For NA engines, this is a great option as the timing can be tailored up to and just back from knock with no MAP issues, as everything is vacuum to atmo based.

I think for turbo engines this is also a workable part. You can easily log the MAP v RPM under normal driving load and create a timing curve just back from knock. You can measure knock easy today with simple knock sensing devices. We sell one that works well that you can adjust out the noise and set your own detonation threshold. Then you can load the engine further and build into the timing curve further safety. I would bet this would be more accurate and net more performance than relying upon the factory mechanical system.

I think many owners over think the ability of the factory system and overrate its ability. The engine last because of low static engine compression numbers and very conservative ignition timing numbers. A lot of the engine capable performance is lost, unfortunately.

Donít get me wrong, the Classic CDI units are not EFI ECUís. but when applied correctly will outperform the factory systems all day long. And they are made to a very high standard, lacking in the older factory units, many of the new aftermarket replacements and for sure, well above anything MSD sells.
Old 03-02-2018, 12:24 PM
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Our SafeGuard unit has boost retard AND individual cylinder knock retard. And an adjustable rev limiter, and Bosch-like dwell controlled ignition...
Old 06-06-2018, 07:54 AM
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