Compatibility of Black Bosch Coil 0 221 121 010 Coil

[1986911]

I would like to know if this # Bosch coil can be used in our 911's and 930's.

I did some searches and did come up with one post from our departed Friend, the Early S Man. He mentioned that the above coil number was interchangeable with 0 221 121 001 coil. Something to do with the 100:1 winding?

I bought a box with some of the 001 coils in it and this one was mixed in with the bunch. Looks to be NOS but cannot claim 100%. Scuffs were from being loose in a box with other coils. Its my last one.

[1986911]

Reaching out to see if anyone has any info on this coil.

[1-ev.com]

I think "010" at the end is the revision number. Here is good Pelican article
History of Bosch CDI ... toubleshooting info, parts list changes, and schematics ...

[wwest]

Originally Posted by 1-ev.com

I think "010" at the end is the revision number. Here is good Pelican article
History of Bosch CDI ... toubleshooting info, parts list changes, and schematics ...

Both of Ops cars use a solid state version of the Kettering ignition system.

The ECU powers the switching power transistor in accordance with engine RPM.

At low RPMs the switch on time is delayed enough that the coil is fully charged at spark time. At the high end there is just enough time to charge the coil between sparks so the ECU doesn't delay the on time.

So the correct coil primary impedance is critical to ignition operation, especially in the high engine RPM range.

Best to stick with the exact one that the factory specified.

[Porchdog]

So with the factory replacement Bosch coils apparently being junk, what to buy if we need a replacement? I don't see many of the original black coils coming up for sale in the classifieds.