Ignitions and Electrical Ignition Components

Denso

IRIDIUM SPARK PLUG

$267.14

SKU: D00A 5703

Special Order
Special Order
Ships in 4–6 weeks
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Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Easy — 1–2 hours

Description

The Denso 5703 is an iridium racing spark plug designed for high-performance applications. It features a special hardened insulator that is 20% stronger, making it suitable for hard-core racing. The plug has a 0.4mm diameter iridium alloy center electrode and a 100% platinum 0.8mm ground electrode to reduce wear and improve ignition performance.

The Denso 5703 utilizes a patented self-cleaning electrode design and a silicone oil-coated insulator to repel moisture and carbon buildup. It is built to handle extreme compression and boost levels, with machine-rolled threads to prevent seizing. The purified alumina powder insulator offers exceptional strength and thermal conductivity, while the five-rib insulator prevents flashover. A copper-glass seal ensures a gas-tight connection between the center electrode and insulator.

Fitment

Fitment Guaranteed

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Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandDenso
Part NumberD00A 5703

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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