High Energy Ignition Systems Jacobs MSD Mallory

[vw505]

I looked for that wireing info for two days so i could hook up my tach.

[mlaiola]

Scott, I found this system online and it does NOT have the rev limiter or anti-theft functions. Is this still a good one to use on a H.P. street VW? It does have the twisted orange & purple wires. Thanks, Mike

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[mlaiola]

I missed one of other pictures for the unit.

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[Scott Novak]

Scott, I found this system online and it does NOT have the rev limiter or anti-theft functions. Is this still a good one to use on a H.P. street VW? It does have the twisted orange & purple wires. Thanks, Mike

Yes it is a great ignition system to use for stock, street or race conditions.

I'm 99.8% sure that this does in fact have both a rev limiter and anti-theft functions. You need to look at the terminal strip underneath the Pro Street.

That looks like it's NOS in the photos.

Also be sure that you are using a NON-resistor rotor, as this ignition system has enough energy to fry a resistor rotor.

Scott Novak

[mlaiola]

Thank you so much for the reply! The backside of the box does NOT have the rev limiter & anti theft checked off? I will have to check it out as you said. Thanks again, Mike

[Jadewombat]

Why use a system like this? You're still stuck with sloppy timing scatter instead of using crank-trigger.

[Scott Novak]

Why use a system like this? You're still stuck with sloppy timing scatter instead of using crank-trigger.

The Jacobs ignition system can also be used with a crank trigger. It doesn't care where it gets it's trigger signal from. And you won't find too many systems that will produce a better spark.

Scott Novak

[Piledriver]

I have a lame RV/street relative of this Jacobs system, and it hit almost as hard as a GM truck cnp coil setup.*

If you want the old school look of a distributor, these systems kick about as good as it gets.

Sadly getting rid of the HV parts of a distributor is the biggest advantage of modern ignition systems.

*I retired it and the early vanagon distributor when I went full sequential ms2. I still use a distributor, it just only has a toothed whee/sensor in it.
There was no spark stability difference distrib vs. crank trigger as far as I could measure, a lot of averaging goes on in the ignition code with a reasonably high tooth count.

VWs dont have timing chain slop like many v8s... that amplified by oil pump load pulsations makes timing scatter a real issue on those.

[Scott Novak]

Sadly getting rid of the HV parts of a distributor is the biggest advantage of modern ignition systems.

In my case the distributor is not an issue, as I modified a huge cap Mallory Comp 9000 Vacuum Advance distributor to fit my Beetle. It can handle anything that a Jacobs ignition can throw at it, at least for 4 - Cylinder applications. It's also rated for 10,000 RPM applications.

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Here is a size comparison between a small Bosch distributor cap, a Mallory Comp 9000, and a Mallory small distributor cap.

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Scott Novak

[Piledriver]

Inspired by your setup, a few years ago I modded a std unilite vw distributor to that cap size using 460 ford cap/rotor and cap base.
Cut down the mallory cap as the adapter, and made a simple rotor adapter.
Worked great.