914-6 Warning Label on Coit, Why is this? Options

[jrrobertson]

Anyone know why this warning is on the coil for a 914-6?

[Cairo94507]

Don't know; but, I need 2 sets of those decals for my coils. (IMG:style_emoticons/default/beerchug.gif)

[Ninja]

Possible reason...

CDI ignition systems might fry your test equipment/fingers if a capacitor discharges during testing.

I've seen warnings like this before on CDI ignition systems.

[DennisV]

Anyone know why this warning is on the coil for a 914-6?

I think that is because you need to make sure the signal is routed through the CDI. Not directly to the coil.

I destroyed a coil on my test stand because I wired ignition directly to the coil instead of through the CDI. (IMG:style_emoticons/default/excl.gif)

@Cairo94507 Aase has a good selection of decals, including coil bracket decal.

[TP914]

I have that bracket , picked it up at a 914 swap meet .

[Superhawk996]

Possible reason...

CDI ignition systems might fry your test equipment/fingers if a capacitor discharges during testing.

I've seen warnings like this before on CDI ignition systems.

(IMG:style_emoticons/default/agree.gif)

Let’s put number to this. A normal inductive coil with points has 12v applied across the coil.

When operating a coil with CDI, the coil will have 200-600v applied across it. It will usually have multiple firing impulses in fast succession instead of just one.

That will destroy typical 12v dwell meters, it will destroy old school analog multi-meters if they were set to 12vdc, and it will give you a heck of a wake up call if you touch the terminals when it’s operating.

The sticker says - you’ve been warned. (IMG:style_emoticons/default/laugh.gif)

[johnhora]

It's there to let you know not to hook up your meter so you don't blow it up and get a nasty shock yourself. It's different than a regular coil.

Classic Porsche 911 (1969–1983) and 930 Turbo models use a specialized Capacitor Discharge Ignition (CDI) coil—technically a step-up transformer rather than a traditional inductive coil—designed to work with Bosch CDI units

A Porsche CDI coil is a pulse transformer rather than a traditional inductive ignition coil.
While they look identical on the outside, they work in fundamentally opposite ways to generate the spark.
The Structural Differences
Feature Traditional Inductive Coil CDI Coil (Pulse Transformer)
Primary Voltage Receives a constant 12V from the battery. Receives a massive, brief pulse of 300V to 450V from the CDI box capacitor.
Primary Resistance High (typically 1.5 to 3.0+ Ohms) to limit current draw. Ultra-Low (typically 0.4 to 0.8 Ohms) to allow an instant dump of power.
Secondary Resistance High (typically 5,000 to 10,000+ Ohms). Low (typically 600 to 900 Ohms).
Spark Generation Fires when the 12V circuit is broken (magnetic field collapses). Fires when the high-voltage pulse is delivered (magnetic field expands instantly).

How it Works (The Breakdown)
1. The Energy Storage: In a regular car, the coil stores energy inside its own magnetic field over milliseconds. In a Porsche CDI system, the energy is stored inside a capacitor inside the Bosch CDI box.
2. The "Hammer" Pulse: When it is time to fire, the CDI box acts like a hammer, releasing 300V to 450V instantly into the low-resistance primary winding of the coil.
3. The Instant Step-Up: Because the CDI coil has an incredibly fast rise time, it steps that 450V pulse up to up to 40,000V on the secondary side in microseconds.
Why you cannot swap them
• Putting a regular coil on a CDI box will result in a weak spark or no spark because its high internal resistance blocks the fast 450V pulse.
• Putting a CDI coil on a regular 12V system will instantly draw too much current due to its ultra-low resistance, overheating the coil and melting your ignition points or electronic ignition module.