I've seen a lot of adverse comments on the the GMS COPs in this forum and I installed a set of their Pro series X on my F-150 when I installed the supercharger last year. Today, I lost one on a trip this evening. When it crapped out, I turned around and came home and after reading the code, I knew which one to replace. At right at 12,000 miles on the set, I'm not impressed. High voltage is not as important as reliability. Should I forget the warranty and install the stock COPs back on my truck? I may rob the cores from the GMS coils and put them on the stockers, if the consensus if to bail.

 

The stock coils are enough to handle the lightning spark plugs so they should be fine. I am running a set of Global Automotive off of ebay.
http://cgi.ebay.ca/IGNITION-COIL-199...item5d2c346a2f

 

stockers are the only way to go

 

Mine found the trash I had 4 replaced by GMS in the first year, and after the warranty was gone I had nothing but problems with them. The stock COPs work fine.

 

What I'm worried about is additional failures and I'll choose reliability over some performance increase. I'm probably going to get that COP replaced under warranty and just change them out for the stock COPs with a new set of plugs in a month or two. But I'm going to keep a stock COP in my tool box until I change them out.

If anyone else has had issues with these COPs post up.

 

I had 4 go out under warranty and after the warranty was up I used the cores with my stock COP's and have had no issues since then. Biggest waste of money.