Granatelli Precision Spark Plug Gapping Tool for Turbo, Supercharged & Performance Engines – 540109

GRANATELLI PRECISION IGNITION TOOLS

DON’T EYEBALL YOUR SPARK PLUG GAP — SET IT.

The Granatelli 540109 Spark Plug Gapping Tool gives racers, engine builders and performance enthusiasts a controlled way to accurately adjust spark plug electrode gap without relying on crude bending or guesswork.

Designed for repeatable spark plug gap adjustment, it is especially useful for turbocharged, supercharged and high-boost engines where the correct plug gap can make the difference between clean ignition and a misfire under load.

IGNITION BASICS THAT ACTUALLY MATTER

Why Spark Plug Gap Matters

Spark plug gap directly affects how the ignition system fires the air/fuel mixture. On high-performance, turbocharged and supercharged engines, increased cylinder pressure can make the spark harder to maintain. A properly set plug gap helps support consistent ignition and reduces the chance of misfire under load.

Precision Without the Guesswork

Built for the Workbench, Race Trailer or Garage

● Turbocharged Engines    ● Supercharged Engines    ● High-Boost Builds    ● Race Engines    ● Street Performance    ● Engine Builders

Why Use a Dedicated Spark Plug Gapping Tool?

TOOL DETAILS

Product Specifications

SPARK PLUG SETUP NOTE

There is no universal “best” spark plug gap. Always set the plug gap according to the engine combination, spark plug manufacturer, ignition system, boost level and tuner or engine-builder recommendation. Measure the final gap with a proper spark plug gap gauge after adjustment.