Recommended for all rotary engines used in racing applications.
Use with thinner spark plug washer to move flash point closer and increase power.
NGK recommends that you start your vehicle and bring up to operating temperature with stock heat range plugs, then switch to the racing plugs.
NGK part numbers:
Product Safety Information
Responsible Person in the EU
Niterra EMEA GmbH
Balcke-Dürr-Allee 6, 40882 Ratingen, Germany
https://www.ngkntk.com/contact 
