Petronix or MSD coil for a 964 motor?
 

On my Rat Rod I am going through the ignition system. I know everyone says the currently available Bosh coils are junk. Just curious why no one seems to use popular canister coils like an MSD, Petronix, etc that are very well respected in the American iron world?

You’re fine Chris. The much maligned Bosch coils are only fitted to engines with CDI. That’s 69 - 83 and Turbos to 89. Your 964 has inductive coils, completely different animals.

The Bosch Silver Coils (Made In Brazil) are junk, only time my car has been flat bedded was because of one of these, brand new coils..most 964 owners aware of the problems with the Silver coils are converting to the 993 coil pack

I've been converting 964s to use the 993 twin E-coils. Just order a couple of new ends for the coil wires to fit the new coils, and it's basically a direct swap.

Coil packs: 993.602.071.01 (Quantity 1)

Could wire ends: 928.602.557.00 (quantity 2)

rubber protection caps: 993.602.801.00 (quantity 2)

The 964 silver coils are junk too? Wow.

It’s understandable that the small silver CDI coils are prone to failure since they deal with 400V on the primary winding. Inductive coils like the 964 only handle 12V so there really is no excuse for failure!

Remember, when the inductive coils (964/993) develop the spark, the primary voltage developed can be 300-350 volts
and for a longer duration (5-10X the CDI spark).