SKU: 76145787795

HKS Super Fire Racing Spark Plug 50003-M525RE

Sale price$57.28 Regular price$63.64
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Description

HKS Super Fire Racing Spark Plug 50003-M525REM Series Super Fire Spark Plugs HKS M Series spark plugs are high performance Iridium plugs designed to provide improved ignition performance, durability and anti carbon build up. 0. 6mm Iridium Alloy Center Electrode Outer Electrode with Platinum Chip Short Type Outer Electrode (Anti Vibration) Thermal Edge Spark Support Gap M Series is recommended for reliable ignition, durability and anti carbon buildup under high load. The Iridium alloy is used

M-Series Super Fire Spark Plugs

HKS M-Series spark plugs are high performance Iridium plugs designed to provide improved ignition performance, durability and anti-carbon build-up.

  • 0.6mm Iridium Alloy Center Electrode
  • Outer Electrode with Platinum Chip
  • Short Type Outer Electrode (Anti-Vibration)
  • Thermal Edge
  • Spark Support Gap

M Series is recommended for reliable ignition, durability and anti-carbon buildup under high load.

The Iridium alloy is used because of its durability and reliability.  On an average plug, a narrow core typically shortens life span of plug but with the intense durability of iridium there is no sacrifice in any longevity.  With a high melting point of 2454 degrees C, opposed to the 1769 degrees C of white gold, the electrode can tolerate the high levels of compression and minor knocking without any deterioration. A nickel coating on the housing also prevents the spark plug from premature deterioration.  The Iridium plugs are available for multiple applications and offered in "colder" heat ranges of 7 and up and specifically for rotary, heat ranges of 9 and up are offered.

Heat Range: NGK # 10.5
Thread Size: 14mm × 12.7mm
Wrench Size: 20.8mm

Fits:

1983 - 1985 MAZDA RX-7 ALL ALL From 10/1983 Thru 9/1985 Production Date  SA22C Chassis  Stock Plug/Heat Range: ROTARY:9
1985 - 1988 MAZDA RX-7 R2 1.3 From 10/1985 Thru 8/1988 Production Date  FC3S/FC3C Chassis  Stock Plug/Heat Range: ROTARY:10,11
1988 - 1991 MAZDA RX-7 R2 1.3 From 9/1988 Thru 12/1991 Production Date  FC3S/FC3C Chassis  Stock Plug/Heat Range: ROTARY:7,9
1993 - 1995 MAZDA RX-7 R2 1.3 From 12/1991 Thru 8/2002 Production Date  FD3S Chassis  Stock Plug/Heat Range: ROTARY:7,9
Shipping Notes
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Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
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SKU: 76145787795

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4.6 ★★★★★
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Nick
Alexandria, US
★★★★★ 5
Good inexpensive sound deadening
Model: 36 Sqft
This stuff works great, it's easy to apply, sticky, easy to cut. 36 ft.² was enough to do the inside and outside of my doors the roof, the wheel wells and rear fenders. Plus, it's a lot cheaper than others.
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Reviewed in the United States on February 8, 2026
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Saif addeen hakouz
Boise, US
★★★★★ 5
Very good quality
Model: 36 Sqft
Very good quality, noticeable difference after installation. The sound deadening effect is clear, with a great reduction in road noise and vibrations. Installation was quick and easy.
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Reviewed in the United States on May 2, 2026
M
Verified Purchase
Mike mcmillion
Grantham, US
★★★★★ 5
just as good as twice price ones
Model: 36 Sqft
super sticky and work phenomenal just as good as name brand ones.just get these and save money for emblem stamps
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Reviewed in the United States on February 18, 2026
H
Verified Purchase
Homer Simpson
Draper, US
★★★★★ 4
Good quality
Model: 36 Sqft
Got it to deaden noisy furnace. Thin galvanized metal sheet feels sturdier and not flexing when blow fan started and stopped. Heavy duty and feel like real butyl material.
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Reviewed in the United States on May 3, 2026
B
Verified Purchase
Bradley
Bozeman, US
★★★★★ 5
Excellent product high quality.
Size: 36 sqft, Size: 36 sqft
This stuff definitely suprised how easy it was to work with. Not to mention it sticks very well. Don't put it on anything you may need to get back into. It will take the paint off of a service area. I have a 2018 dodge durango. I just had a aftermarket audio sytem installed. It was rattling so bad it was driving me crazy. I seen this stuff and decided to give it a try. Its a night and day difference no moore rattling. I box will be enough to do my back gate and all front and rear doors also. For the price you honestly can not beat it. If your on the fence about trying it don't be. You definitely won't regret getting it. Its worth every penny. You don't realize how much something rattling in your vehicle robs you of spund quality. Glad I made the decision. Now off to the other 4 doors. ,and then the roof. One of the things I really like was the fact it has multiple line to help you make even better cuts. Definitely will buy a gen.
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Reviewed in the United States on February 28, 2026

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