NGK Racing Spark Plug – R7437-8 (Stock No. 4901)
The NGK R7437-8 is a purpose-built racing spark plug designed for tuned performance engines running Stage 1 maps and beyond. If you’re pushing your engine harder than standard and want to keep ignition consistent under load, this is the plug to fit. As an authorised NGK dealer, we supply only genuine NGK Racing plugs.
Sold individually. Please remember to add the correct quantity to your cart for your engine (typically one per cylinder).
Why fit the NGK R7437-8?
Tuning your car increases cylinder pressures and combustion temperatures, which can overwhelm standard spark plugs. When that happens, you can experience misfires, hesitation, or a noticeable drop in performance under boost. The R7437-8 is a colder, race-grade plug that handles those higher demands, helping to deliver a stable spark when the engine needs it most.
The fine wire iridium centre electrode produces a focused, reliable spark and resists wear far better than standard nickel plugs. A copper core helps shift heat away from the tip, while corrugated ribs on the insulator help prevent voltage tracking (known as flashover) at high loads.
- Fine wire iridium centre electrode for a strong, consistent spark
- Heat range 8 – a colder plug suited to tuned and high-output engines
- Copper core for efficient heat dissipation
- Trivalent metal plating to resist corrosion and seizing
- Triple gasket seals to prevent combustion gas leakage
- Pure alumina silicate ceramic insulator for strength and heat transfer
Gap Setting
Always consult your tuner for the gap they recommend for your specific map. As a general guide, we advise setting the gap to 0.6mm (+/- 0.05mm). Most performance tuners prefer a tighter gap than standard, as this helps the ignition system fire cleanly under boost and prevents misfires. Check the gap with a feeler gauge before fitting and adjust carefully if needed.
Technical Specifications
| Thread Size | 14mm |
| Thread Pitch | 1.25mm |
| Reach | 26.5mm (1.04″) |
| Hex Size | 16mm (5/8″) |
| Seat Type | Gasket |
| Heat Range | 8 (colder) |
| Resistor Value | 5K Ohm |
| Terminal Type | Solid |
| Centre Electrode | Iridium, Fine Wire, 0.6mm, Projected |
| Ground Electrode | Nickel, Taper Cut |
| Factory Gap | 0.7mm (adjust as advised by tuner) |
| Torque (Aluminium Head) | 18 – 21.6 lb-ft |
| Torque (Cast Iron Head) | 18 – 25.3 lb-ft |
Fitment
The R7437-8 is a popular choice across a wide range of tuned VW, Audi, SEAT, Skoda, BMW and other turbocharged petrol applications running uprated software. Please use the vehicle lookup tool on our site or refer to the Vehicle Fitment tab to confirm suitability for your car, and always cross-check with your tuner’s recommendation.
About NGK Racing Spark Plugs
NGK is the world’s leading spark plug manufacturer, supplying both original equipment to major car makers and ignition components to top-tier motorsport including F1, WRC and MotoGP. NGK Racing plugs are built specifically for the harsh conditions inside a competition engine, with fine-wire electrodes for improved sparking, a zinc-dipped shell to prevent corrosion, and special insulator profiles that help throttle response and reduce fouling.
For tuners and enthusiasts running modified cars, NGK Racing plugs are the proven, reliable choice to keep your ignition working properly when your engine is making more power than the factory ever intended.
Applications
Please note, customers are wholly responsible for checking fitment for their vehicle.



