Fab9 Tuning Coil on Plug Upgrade

Difficulty: 2/5

Time to install: 20 mins for immediate install and test, plus whatever time left you want to spend removing remaining OEM parts or wire looms

Tools Required:

    • Socket and Ratchet set to install new spark plugs,

    • Drill and/or screwdriver to mount the coil driver.

Replacement Parts

Like many boutique Miata parts sometimes vendors come and go. So priority 1, document a few things for future maintenance:

  • Ignitor

    • Bosch 0227100211 or 4D0 905 351 - I've used this ignitor and confirm it works.

    • Or the Meyle equivalent brand

  • Coil Packs/Coil on Plugs

    • Denso 129700-5150

    • Denso 129700-5140

    • Coil on Plugs for a 2008-2009 or 2012-2019 Suzuki GSXR 600

  • Spark Plugs

    • The most important part here is that the plug connector can screw off.

    • Bosch Super Plus 7956 - This is 1 step colder for a 1991 Miata - I've used these plus and confirm it works.

    • Bosch 9652


Original Part Notes

    1. Should the igniters die in the future, it's a Denso and printed on the side is: 129700-5230 JO523 03P0512028. Not sure if that's the whole part number, or some of it and other numbers are a manufacturing lot number. I guess I'll figure that out someday should they need to be replaced.

    2. The kit uses one of 3 Denso "Iridium Power" spark plugs, depending on your application:

      1. Naturally Aspirated: IK16

      2. Forced Induction < 16psi: IK22. Note, I bought this setup. Here's other info from the box:

        1. 0.4mm gap

        2. IK22#4 / 5310#4 / I03

      3. Forced Induction > 16psi: IK24

Instructions attached at bottom (no PDF available on vendor site).