Racing Spark Plug 4140

【NGK R5673-8 Racing Spark Plug 4140 ngk r5673-8-4140】
Racing spark plugs, recommended for two-wheel and four-wheel vehicles, are available in various types aimed at further performance improvement when used in races, circuit driving, or with engines that have increased output due to tuning.
Consequently, their shape differs from the manufacturer's standard plugs, and the plug's lifespan and low-speed performance may be slightly compromised.
However, on the other hand, they are developed and designed to fully demonstrate their performance even in highly tuned engines and extremely severe operating conditions, with a wide range of heat ratings.
Please select the appropriate plug for your specific engine to achieve its full potential.
Important points when choosing racing spark plugs
Determine the screw size, plug type, and shape from the part number of your genuine plug or the plug you are currently using, and then select the corresponding type.
Please refer to the manufacturer's website for guidance on selecting the ignition tip shape.
The heat rating needs to be selected to maintain the optimal temperature range of the plug's ignition tip, taking into account the increased combustion temperature due to improved engine output and operating conditions.
Simply increasing the heat rating alone will not improve engine performance.
Generally, heat ratings of 7-8 are used for street driving, 8-9 for track day specifications, and 9-10 for race specifications.
The presence or absence of a resistor in the spark plug makes little difference nowadays due to improvements in ignition system performance.
Resistor types will become the mainstream in the future.
Conversely, non-resistor types may cause engine trouble in some models of certain vehicle types.
In such cases, please be sure to use the resistor type.
*The image is for illustration purposes only, and the design and specifications of the products shown may change without prior notice. Thank you for your understanding.