Harddrive HD Performance Coils - 40v-HP Single Fire Coil Twin CAM EFI — Harley-Davidson Road King, Road King Classic, Electra Glide (2001-2017)

Harddrive HD Performance 40V single-fire coil for Twin Cam EFI Harley-Davidson models, engineered to deliver 30,000 volts with ION Sense feedback compatible with stock EFI systems. Increases peak spark voltage by 20% or more to improve cold starts, eliminate high-speed misfires, and boost fuel economy.

Features

• 30,000-volt high-power output
• ION Sense feedback for stock EFI ECU compatibility
• Single-fire and dual-fire application support
• Increases peak spark voltage 20% or more
• Improves cold-weather starting and high-speed stability

Specifications

• Brand: Harddrive
• Manufacturer Part #: 10-2003
• UPC: 191361439452
• Voltage Output: 30,000 volts
• Dimensions: 5 in L × 3 in W × 4 in H
• Weight: 3 lbs
• Country of Origin: China (Mainland)

Fitment

Fits V-twin motorcycles with Twin Cam EFI engines and stock Harley-Davidson fuel management systems.

Frequently Asked Questions

Will this coil work with my stock Harley EFI?

Yes — ION Sense feedback is engineered for direct compatibility with Harley's stock EFI ECU without additional tuning or modules.

Does this fit both single-fire and dual-fire systems?

Yes — this coil supports both single-fire and dual-fire ignition applications.

How much hotter is this spark compared to stock?

Peak spark voltage increases by 20% or more over OEM specs, resulting in faster ignition and stronger combustion.

Will this improve my fuel mileage?

Yes — improved spark performance typically increases miles per gallon and overall engine efficiency, especially at highway speeds.

Is installation difficult?

Single coil swap — disconnect the OEM coil and plug in the Harddrive unit. No ECU reflash or tuning required.