NGK R5673-8 (4140) Racing Spark Plug

SKU: NGK_4140_x_1
In stock

£3.10

Why Buy?
  • We’re a genuine & direct NGK UK supplier
  • Used by many of the biggest names in motorsport today
  • Precious metals are used for greater durability and lower voltage requirements
  • Fine wire electrodes (depending on P/N) provide better sparking for enhanced ignitability
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Description

NGK R5673-8 (4140) Racing Spark Plug

From professional racers with extremely modified engines to the weekend warrior, all levels of performance enthusiasts can rely on the advanced technology that’s built into all NGK racing spark plugs. They can be found in virtually every pit lane around the globe, and with a proven track record, they’re a winning solution with unbeatable reliability and performance.

To withstand the harshest of conditions that occur in the most powerful, high-compression racing engines, NGK racing spark plugs usually differ from normal spark plugs in both appearance and performance. They usually feature precious metal electrodes such as platinum or gold/palladium for greater durability and the lower voltage requirements means easier starting.

Choosing a Racing Spark Plug:

  1. Shell design To determine what kind of shell design fits in your engine, check the serial number of regulation plugs or the plugs you are currently using to verify the thread diameter, pitch, thread length and shell seat.
  2. Firing End Design Refer to the section below on electrode design to determine which type is best for your needs.
  3. Heat range It’s important to choose a racing plug with a heat range that keeps the electrode at an optimum temperature under even the most torturous racing conditions. And remember: A higher heatrange number does not improve engine performance, it increases the plug’s ability to dissipate heat.
  4. Resistors Due to advances in ignition system technology, there is little if any difference in performance between plugs with resistors and those without. However, there are still some variations of some models that require plugs with resistors to avoid engine trouble.

Choosing an Electrode Design

Although a good rule of thumb is that the more an electrode projects into the cylinder, the better ignition it provides, it’s also true that longer projections are more susceptible to the wear and tear of extreme temperatures. High-power, high-performance engines run hotter and vibrate more, which is why we recommend choosing a firing end design that reduces exposure of the electrode and insulator as much as possible.

Projected Type

image-2

Quite similar to a standard spark plug electrode configuration, these plugs give a good overall performance in lightly tuned and naturally aspirated engines, as well as good performance in the low to medium torque range in turbo engines.

Angled Ground Strap Type

image-1

These provide superior performance in turbocharged engines with power boosts of 50% or more. The short-ground electrode is also highly durable against mechanical shock.

Semisurface Discharge Type

image

In a sense, this is the ultimate plug configuration. Nearly all insulator cracking and electrode melting can be prevented with this type. Nevertheless, service life and low-speed performance may suffer slightly.

racing

NGK & NTK are brands of Niterra Co., Ltd.See more information here

Additional Information

Brand

NGK

Compatibility

Please use the NGK Part Finder links and guides below to confirm compatibility with your vehicle. If you're unsure, please contact us:

Tags/OE Part Numbers

Quick Comparison

SettingsNGK R5673-8 (4140) Racing Spark Plug removeNGK BKR7EIX (2667) Iridium IX Spark Plug removeNGK BKR8EIX (2668) Iridium IX Spark Plug removeNGK CR8EHIX-9 (3797) Iridium IX Spark Plug removeNGK DR9EIX (4772) Iridium IX Spark Plug removeNGK BR8ECMIX (3520) Iridium IX Spark Plug remove
NameNGK R5673-8 (4140) Racing Spark Plug removeNGK BKR7EIX (2667) Iridium IX Spark Plug removeNGK BKR8EIX (2668) Iridium IX Spark Plug removeNGK CR8EHIX-9 (3797) Iridium IX Spark Plug removeNGK DR9EIX (4772) Iridium IX Spark Plug removeNGK BR8ECMIX (3520) Iridium IX Spark Plug remove
Imager5673 8bkr7eix.jpgbkr8eix.jpgcr8ehix-9.jpgdr9eix.jpgbr8ecmix.jpg
SKUNGK_4140_x_1NGK_2667_x_1NGK_2668_x_1NGK_3797_x_1NGK_4772_x_1NGK_3520_x_1
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Price£3.10£10.43£10.77£11.60£11.11£12.10
AvailabilityIn stock1 Working Day(s) Until Dispatch1 Working Day(s) Until Dispatch5 Working Day(s) Until Dispatch1 Working Day(s) Until Dispatch5 Working Day(s) Until Dispatch
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Description
Why Buy?
  • We're a genuine & direct NGK UK supplier
  • Used by many of the biggest names in motorsport today
  • Precious metals are used for greater durability and lower voltage requirements
  • Fine wire electrodes (depending on P/N) provide better sparking for enhanced ignitability
Why Buy?
  • 100% genuine NGK spark plugs
  • 0.6mm fine iridium centre electrode tip
  • Easier engine starts - Great for freezing winter mornings.
  • Superior anti-fouling
  • Proven track record and used in millions of vehicles around the world.
  • Long lifespan
  • Superior design and tooling
  • No flashover
  • No need for copper grease
  • https://www.ngkpartfinder.co.uk/
Why Buy?
  • 100% genuine NGK spark plugs
  • 0.6mm fine iridium centre electrode tip
  • Easier engine starts - Great for freezing winter mornings.
  • Superior anti-fouling
  • Proven track record and used in millions of vehicles around the world.
  • Long lifespan
  • Superior design and tooling
  • No flashover
  • No need for copper grease
  • https://www.ngkpartfinder.co.uk/
Why Buy?
  • 100% genuine NGK spark plugs
  • 0.6mm fine iridium centre electrode tip
  • Easier engine starts - Great for freezing winter mornings.
  • Superior anti-fouling
  • Proven track record and used in millions of vehicles around the world.
  • Long lifespan
  • Superior design and tooling
  • No flashover
  • No need for copper grease
  • https://www.ngkpartfinder.co.uk/
Why Buy?
  • 100% genuine NGK spark plugs
  • 0.6mm fine iridium centre electrode tip
  • Easier engine starts - Great for freezing winter mornings.
  • Superior anti-fouling
  • Proven track record and used in millions of vehicles around the world.
  • Long lifespan
  • Superior design and tooling
  • No flashover
  • No need for copper grease
  • https://www.ngkpartfinder.co.uk/
Why Buy?
  • 100% genuine NGK spark plugs
  • 0.6mm fine iridium centre electrode tip
  • Easier engine starts - Great for freezing winter mornings.
  • Superior anti-fouling
  • Proven track record and used in millions of vehicles around the world.
  • Long lifespan
  • Superior design and tooling
  • No flashover
  • No need for copper grease
  • https://www.ngkpartfinder.co.uk/
Content

NGK R5673-8 (4140) Racing Spark Plug

From professional racers with extremely modified engines to the weekend warrior, all levels of performance enthusiasts can rely on the advanced technology that's built into all NGK racing spark plugs. They can be found in virtually every pit lane around the globe, and with a proven track record, they're a winning solution with unbeatable reliability and performance.

To withstand the harshest of conditions that occur in the most powerful, high-compression racing engines, NGK racing spark plugs usually differ from normal spark plugs in both appearance and performance. They usually feature precious metal electrodes such as platinum or gold/palladium for greater durability and the lower voltage requirements means easier starting.

Choosing a Racing Spark Plug:

  1. Shell design To determine what kind of shell design fits in your engine, check the serial number of regulation plugs or the plugs you are currently using to verify the thread diameter, pitch, thread length and shell seat.
  2. Firing End Design Refer to the section below on electrode design to determine which type is best for your needs.
  3. Heat range It's important to choose a racing plug with a heat range that keeps the electrode at an optimum temperature under even the most torturous racing conditions. And remember: A higher heatrange number does not improve engine performance, it increases the plug's ability to dissipate heat.
  4. Resistors Due to advances in ignition system technology, there is little if any difference in performance between plugs with resistors and those without. However, there are still some variations of some models that require plugs with resistors to avoid engine trouble.

Choosing an Electrode Design

Although a good rule of thumb is that the more an electrode projects into the cylinder, the better ignition it provides, it's also true that longer projections are more susceptible to the wear and tear of extreme temperatures. High-power, high-performance engines run hotter and vibrate more, which is why we recommend choosing a firing end design that reduces exposure of the electrode and insulator as much as possible.

Projected Type

image-2

Quite similar to a standard spark plug electrode configuration, these plugs give a good overall performance in lightly tuned and naturally aspirated engines, as well as good performance in the low to medium torque range in turbo engines.

Angled Ground Strap Type

image-1

These provide superior performance in turbocharged engines with power boosts of 50% or more. The short-ground electrode is also highly durable against mechanical shock.

Semisurface Discharge Type

image

In a sense, this is the ultimate plug configuration. Nearly all insulator cracking and electrode melting can be prevented with this type. Nevertheless, service life and low-speed performance may suffer slightly.

racing

NGK & NTK are brands of Niterra Co., Ltd. - See more information here

NGK BKR7EIX (2667) Iridium IX Spark Plug

The Spark Plug Serious Enthusiasts Rely On.

NGK Iridium IX spark plugs have achieved global recognition and success. Since their initial introduction, NGK Iridium IX spark plugs have consistently proven to be an exceptional upgrade, and they have now become a preferred choice in millions of vehicles worldwide.

 

The Winning Combination

The reason behind their immense popularity lies in their unique design, which features a smaller albeit harder center electrode. This design enables a more complete and unobstructed burn in the combustion chamber. As a result, these spark plugs offer several advantages such as enhanced throttle response, superior anti-fouling properties, improved fuel efficiency (MPG), easier cold starts, and an extended lifespan.

The winning combination contributes to an overall increase in performance, surpassing the capabilities of standard nickel spark plugs. Moreover, the Iridium IX spark plugs excel in all areas where traditional spark plugs made of nickel may encounter limitations.

The exceptional melting point of iridium, which is significantly higher than that of other materials, makes it perfectly suited for modern high-temperature engines. This characteristic ensures outstanding acceleration, fuel efficiency, and durability, further solidifying the reputation of NGK Iridium IX spark plugs as a top choice for automotive enthusiasts and professionals alike.

 

Iridium IX Benefits:

  • The fine iridium tip ensures high durability and a consistently stable spark
  • Iridium alloy has an extremely high melting point, perfect for today's high-tech, high-performance engines
  • Trivalent Metal Plating - superior anti-corrosion and anti-seizing properties - no anti-seize lubricant needed!
  • Outstanding acceleration, high fuel efficiency and durability
  • Ultimate design, technology and performance.
  • Longer service life than nickel spark plugs
  • Improves idling & throttle response.
  • Better electrode anti-oxidation
  • Better electrode anti-erosion
  • Improved ignition
  • Easier engine starts due to a lower required voltage means less load on the battery.
  • Allows the use of an extremely small diameter electrode (0.6mm) without compromising the spark plug's service life
  • Superior anti-fouling

 

iridium ix

NGK & NTK are brands of Niterra Co., Ltd. - See more information here

NGK BKR8EIX (2668) Iridium IX Spark Plug

The Spark Plug Serious Enthusiasts Rely On.

NGK Iridium IX spark plugs have achieved global recognition and success. Since their initial introduction, NGK Iridium IX spark plugs have consistently proven to be an exceptional upgrade, and they have now become a preferred choice in millions of vehicles worldwide.

 

The Winning Combination

The reason behind their immense popularity lies in their unique design, which features a smaller albeit harder center electrode. This design enables a more complete and unobstructed burn in the combustion chamber. As a result, these spark plugs offer several advantages such as enhanced throttle response, superior anti-fouling properties, improved fuel efficiency (MPG), easier cold starts, and an extended lifespan.

The winning combination contributes to an overall increase in performance, surpassing the capabilities of standard nickel spark plugs. Moreover, the Iridium IX spark plugs excel in all areas where traditional spark plugs made of nickel may encounter limitations.

The exceptional melting point of iridium, which is significantly higher than that of other materials, makes it perfectly suited for modern high-temperature engines. This characteristic ensures outstanding acceleration, fuel efficiency, and durability, further solidifying the reputation of NGK Iridium IX spark plugs as a top choice for automotive enthusiasts and professionals alike.

 

Iridium IX Benefits:

  • The fine iridium tip ensures high durability and a consistently stable spark
  • Iridium alloy has an extremely high melting point, perfect for today's high-tech, high-performance engines
  • Trivalent Metal Plating - superior anti-corrosion and anti-seizing properties - no anti-seize lubricant needed!
  • Outstanding acceleration, high fuel efficiency and durability
  • Ultimate design, technology and performance.
  • Longer service life than nickel spark plugs
  • Improves idling & throttle response.
  • Better electrode anti-oxidation
  • Better electrode anti-erosion
  • Improved ignition
  • Easier engine starts due to a lower required voltage means less load on the battery.
  • Allows the use of an extremely small diameter electrode (0.6mm) without compromising the spark plug's service life
  • Superior anti-fouling

 

iridium ix

NGK & NTK are brands of Niterra Co., Ltd. - See more information here

NGK CR8EHIX-9 (3797) Iridium IX Spark Plug

The Spark Plug Serious Enthusiasts Rely On.

NGK Iridium IX spark plugs have achieved global recognition and success. Since their initial introduction, NGK Iridium IX spark plugs have consistently proven to be an exceptional upgrade, and they have now become a preferred choice in millions of vehicles worldwide.

 

The Winning Combination

The reason behind their immense popularity lies in their unique design, which features a smaller albeit harder center electrode. This design enables a more complete and unobstructed burn in the combustion chamber. As a result, these spark plugs offer several advantages such as enhanced throttle response, superior anti-fouling properties, improved fuel efficiency (MPG), easier cold starts, and an extended lifespan.

The winning combination contributes to an overall increase in performance, surpassing the capabilities of standard nickel spark plugs. Moreover, the Iridium IX spark plugs excel in all areas where traditional spark plugs made of nickel may encounter limitations.

The exceptional melting point of iridium, which is significantly higher than that of other materials, makes it perfectly suited for modern high-temperature engines. This characteristic ensures outstanding acceleration, fuel efficiency, and durability, further solidifying the reputation of NGK Iridium IX spark plugs as a top choice for automotive enthusiasts and professionals alike.

 

Iridium IX Benefits:

  • The fine iridium tip ensures high durability and a consistently stable spark
  • Iridium alloy has an extremely high melting point, perfect for today's high-tech, high-performance engines
  • Trivalent Metal Plating - superior anti-corrosion and anti-seizing properties - no anti-seize lubricant needed!
  • Outstanding acceleration, high fuel efficiency and durability
  • Ultimate design, technology and performance.
  • Longer service life than nickel spark plugs
  • Improves idling & throttle response.
  • Better electrode anti-oxidation
  • Better electrode anti-erosion
  • Improved ignition
  • Easier engine starts due to a lower required voltage means less load on the battery.
  • Allows the use of an extremely small diameter electrode (0.6mm) without compromising the spark plug's service life
  • Superior anti-fouling

 

iridium ix

NGK & NTK are brands of Niterra Co., Ltd. - See more information here

NGK DR9EIX (4772) Iridium IX Spark Plug

The Spark Plug Serious Enthusiasts Rely On.

NGK Iridium IX spark plugs have achieved global recognition and success. Since their initial introduction, NGK Iridium IX spark plugs have consistently proven to be an exceptional upgrade, and they have now become a preferred choice in millions of vehicles worldwide.

 

The Winning Combination

The reason behind their immense popularity lies in their unique design, which features a smaller albeit harder center electrode. This design enables a more complete and unobstructed burn in the combustion chamber. As a result, these spark plugs offer several advantages such as enhanced throttle response, superior anti-fouling properties, improved fuel efficiency (MPG), easier cold starts, and an extended lifespan.

The winning combination contributes to an overall increase in performance, surpassing the capabilities of standard nickel spark plugs. Moreover, the Iridium IX spark plugs excel in all areas where traditional spark plugs made of nickel may encounter limitations.

The exceptional melting point of iridium, which is significantly higher than that of other materials, makes it perfectly suited for modern high-temperature engines. This characteristic ensures outstanding acceleration, fuel efficiency, and durability, further solidifying the reputation of NGK Iridium IX spark plugs as a top choice for automotive enthusiasts and professionals alike.

 

Iridium IX Benefits:

  • The fine iridium tip ensures high durability and a consistently stable spark
  • Iridium alloy has an extremely high melting point, perfect for today's high-tech, high-performance engines
  • Trivalent Metal Plating - superior anti-corrosion and anti-seizing properties - no anti-seize lubricant needed!
  • Outstanding acceleration, high fuel efficiency and durability
  • Ultimate design, technology and performance.
  • Longer service life than nickel spark plugs
  • Improves idling & throttle response.
  • Better electrode anti-oxidation
  • Better electrode anti-erosion
  • Improved ignition
  • Easier engine starts due to a lower required voltage means less load on the battery.
  • Allows the use of an extremely small diameter electrode (0.6mm) without compromising the spark plug's service life
  • Superior anti-fouling

 

iridium ix

NGK & NTK are brands of Niterra Co., Ltd. - See more information here

NGK BR8ECMIX (3520) Iridium IX Spark Plug

The Spark Plug Serious Enthusiasts Rely On.

NGK Iridium IX spark plugs have achieved global recognition and success. Since their initial introduction, NGK Iridium IX spark plugs have consistently proven to be an exceptional upgrade, and they have now become a preferred choice in millions of vehicles worldwide.

 

The Winning Combination

The reason behind their immense popularity lies in their unique design, which features a smaller albeit harder center electrode. This design enables a more complete and unobstructed burn in the combustion chamber. As a result, these spark plugs offer several advantages such as enhanced throttle response, superior anti-fouling properties, improved fuel efficiency (MPG), easier cold starts, and an extended lifespan.

The winning combination contributes to an overall increase in performance, surpassing the capabilities of standard nickel spark plugs. Moreover, the Iridium IX spark plugs excel in all areas where traditional spark plugs made of nickel may encounter limitations.

The exceptional melting point of iridium, which is significantly higher than that of other materials, makes it perfectly suited for modern high-temperature engines. This characteristic ensures outstanding acceleration, fuel efficiency, and durability, further solidifying the reputation of NGK Iridium IX spark plugs as a top choice for automotive enthusiasts and professionals alike.

 

Iridium IX Benefits:

  • The fine iridium tip ensures high durability and a consistently stable spark
  • Iridium alloy has an extremely high melting point, perfect for today's high-tech, high-performance engines
  • Trivalent Metal Plating - superior anti-corrosion and anti-seizing properties - no anti-seize lubricant needed!
  • Outstanding acceleration, high fuel efficiency and durability
  • Ultimate design, technology and performance.
  • Longer service life than nickel spark plugs
  • Improves idling & throttle response.
  • Better electrode anti-oxidation
  • Better electrode anti-erosion
  • Improved ignition
  • Easier engine starts due to a lower required voltage means less load on the battery.
  • Allows the use of an extremely small diameter electrode (0.6mm) without compromising the spark plug's service life
  • Superior anti-fouling

 

iridium ix

NGK & NTK are brands of Niterra Co., Ltd. - See more information here

Weight0.04 kg0.05 kg0.05 kg0.03 kg0.04 kg0.05 kg
DimensionsN/AN/AN/AN/AN/AN/A
Additional information
Brand

NGK

Brand

NGK

Brand

NGK

Brand

NGK

Brand

NGK

Brand

NGK