Spark Plugs

Spark Plugs are a very important part to tuning your engine. Many tuners here in Japan say that in countries where gas quality is less than here in Japan, ignition and spark plugs have even more importance in tuning. The key factors to high horsepower is good quality gas, good ignition, and ignition timing and because good gas is not always accessible you will definitely need good spark plugs.

The Spark Plug has a two major requirements, one is to provide a good spark and the other is to keep cool. If a spark plug becomes too hot due to high boost or high compression it may cause detonation or knock. Detonation, knock, or also called pre-ignition will destroy your engine and should be avoided like the plague.

Spark plugs are rated with a heat range from 6 to 10. This is not the case with the Wankle engine as rotary engines are rated at 9 to 11. A heat rating of 6 is for stock piston engined cars and 10 is for highly modified cars. While there is no specific formula we can offer in determining what plug heat range you need most mildly tuned piston engines use one heat range higher than the stock 6. The most popular and widely used plugs here in Japan are the HKS M Series plugs. There are many other types of spark plugs out there and many different types of engine tunes so it sort of comes down to personal choice for many. We always recommend HKS M Series over all others.

You can view these JDM parts Spark Plugs