HKS SUPER FIRE RACING M40i HKS HKS50003-M40I
HKS SUPER FIRE RACING M40i HKS HKS50003-M40I
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HKS SUPER FIRE RACING M40i

HKS
HKS50003-M40I
4957266720240
Spark Plugs
18 Units In Stock - Ships Next Business Day
$ 270.00
FREE Ground Shipping!
$ 270.00

SKU: 50003-M40I | UPC: 4957266720240

HKS SUPER FIRE RACING M40i for Nissan Skyline R33-R34 RB25DET Toyota JZX100 1JZ-GTE Subaru WRX

HKS Super Fire Racing M40i is a high-performance iridium spark plug for turbocharged JDM engines. It fits Nissan Skyline R33-R34 RB25DET, Toyota Mark II Chaser Cresta JZX100 1JZ-GTE, Subaru Impreza WRX GC8 EJ20 and more. This plug provides focused spark energy for quicker combustion, sharper throttle response, and added power in high-rev setups.

Key Features

  • 0.4mm Iridium Center Electrode: Pinpoint spark concentration ignites lean mixtures reliably at redline speeds
  • Platinum Ground Electrode with Taper Cut: Accelerates flame growth while minimizing quenching for fuller combustion chamber fill
  • M40i Heat Range: Resists fouling in boosted applications with elevated cylinder temps and pressures
  • OEM Dimensions: 14mm thread, 26.5mm reach, 16mm hex for drop-in replacement without clearance issues
  • Racing Durability: Outlasts nickel plugs under extreme track conditions with consistent output

Product Notes

  • For modified or racing engines. stock use possible but performance shines in tuned setups
  • Factory gapped to 0.8-0.9mm. verify with feeler gauge before install
  • Single plug packaging. order sets of 6 for inline-6 or 4 for inline-4 engines

Installation Notes

  • Professional installation recommended.
  • Torque to 20-25 Nm (15-18 ft-lbs) using anti-seize on threads
  • Works with OEM ignition coils and plug wires

This Part Fits

Year Make Model Submodel
1993-1998 Nissan Skyline R33 RB25DET
1998-2002 Nissan Skyline R34 RB25DET
1999-2002 Nissan Silvia S15 SR20DET
1996-2000 Toyota Mark II JZX100 1JZ-GTE
1996-2000 Toyota Chaser JZX100 1JZ-GTE
1996-2000 Toyota Cresta JZX100 1JZ-GTE
1991-2000 Toyota Aristo 2JZ-GTE
1996-2000 Subaru Impreza WRX GC8 EJ20

Why Choose HKS?

  • Motorsport-proven components trusted in JDM racing circuits
  • Exact tolerances from Japanese factory production
  • Advanced materials extend service intervals in demanding conditions

Frequently Asked Questions

  • Q: Will this plug fit my RB25DET swap?
    A: Yes, direct OEM replacement for stock plugs in R33-R34 Skyline RB25DET engines with no modifications
  • Q: What material is the center electrode?
    A: Pure iridium alloy, 0.4mm diameter for superior spark focus and anti-fouling resistance
  • Q: What is the warranty and lifespan?
    A: HKS 1-year limited warranty. expect 40,000+ miles in street use, longer with proper maintenance

Shipping & Handling

  • Method: UPS or FedEx Ground
  • Availability: In stock - ships same or next business day
  • Packaging: HKS OEM box, 3.1 x 1 x 1 inches
  • Weight: 0.1 lbs

Request For Information

Have questions about HKS SUPER FIRE RACING M40i? Fill out the form below and we'll get back to you by the next business day.
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