NGK Iridium Spark Plug
NGK Spark Plugs · Part number BR9EIX · NZ$42.00 incl. GST
G'day!
Price
NZ$42.00 including GST. Part number BR9EIX.
Fits these vehicles
- Porsche 911 (1974–1983)
- Porsche 911 (1975–1977)
- Porsche 911 (1977–1980)
- Porsche 911 (1979–1980)
- Porsche 911 (1980–1983)
- Porsche 924 (1977–1982)
Description
Give Your Classic Porsche Its Spark Back!
> Right then, let's talk spark plugs. These little legends are what kick off the whole combustion party in your engine. For classic air-cooled Porsches like your 911 SC or 924, where the engine's relying on good old airflow and oil to stay cool, knackered plugs can throw a real spanner in the works. You'll get incomplete combustion, cylinder temperatures going through the roof, and that annoying flat-spot mid-rev that just guts the legendary throttle response these beauties are known for.
Symptoms That Led You Here
• Hard starting, especially when cold on crisp NZ mornings
• Rough idle that smooths out once warm
• Noticeable hesitation or flat-spot between 3,000-4,500 RPM
• Increased fuel consumption on your weekend canyon runs
• Engine misfires under load or during spirited driving
• Failed emissions at WOF inspection
• Fouled or oil-contaminated plugs on removal
Will it pass WOF?
Yes, spark plugs themselves aren't a direct WOF inspection item, but the symptoms of worn plugs—excessive emissions, rough running, and potential catalytic converter damage—absolutely can cause a WOF failure. Classic Porsches with carburettor or CIS fuel injection are particularly sensitive to plug condition for maintaining compliant exhaust emissions.
DIY or Workshop?
Difficulty: 6/10 | Time: 1-2 hours | Tools: Spark plug socket (typically 16mm or 21mm depending on plug type), extension bar, torque wrench, anti-seize compound, feeler gauge for gap checking
The horizontally-opposed flat-six in your 911 SC means plugs are accessed from underneath or through the engine bay sides—not the most comfortable position. The 924's front-mounted inline-four is more straightforward. Either way, working on these classics requires patience and care to avoid cross-threading in aluminium heads.
Expert Recommendation
Classic air-cooled Porsches demand ignition components that can handle the thermal stress of their unique cooling design. Bob @ CARFIX recommends the NGK spark plug for this application—NGK's heritage in motorsport and their copper-core technology delivers consistent spark energy across the wide temperature ranges these engines experience. Bob @ CARFIX is always on hand to help you work out exactly what plug heat range and gap specification suits your classic Porsche. Make sure you head over to Bob's Shop for a chat!
Fitment Notes
• Confirmed fitment for Porsche 911 SC and SC Carrera variants from 1974-1983
• Also suits Porsche 924 (non-Turbo) from 1977-1982
• Always verify plug gap against your specific model's specifications—these varied across production years
• Air-cooled 911s may require different heat ranges if modified or used primarily for track days
• Replace plugs as a complete set to maintain balanced combustion across all cylinders
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🛠️ Bob's Pro Tip: Do the Job Right!
> If you're replacing this spark plug, make sure you've got the right workshop prep, protection, and safety gear ready. Taking a bit of extra time and using the proper safety stands and cleaners makes all the difference for a professional result!
🧰 What Else You'll Need:
• Safety First: Always secure your vehicle on heavy-duty safety jack stands before working underneath. Never rely solely on a hydraulic jack.
• Clean Hands: Keep a pack of Nitrile Gloves handy to protect your skin from grease, oils, and chemical sprays.
• Preparation: Have microfibre towels and a suitable parts cleaner nearby to keep components clean during installation.