Moroso 28322 Ultra 40 Spiral Core Spark Plug Wire Set for Harley-Davidson Softail, FXD, FL

The Moroso Ultra 40 Spark Plug Wire Set (PN 28322) is a race-proven, high-performance ignition wire set engineered specifically for Harley-Davidson Softail, FXD, and FL models. Built to the same exacting standards used in professional motorsports — from dual-mag Top Fuel dragsters to NASCAR Cup Series — this wire set delivers maximum spark energy and superior noise suppression for street and performance riding alike.

Key Features:

• 8.65mm diameter spiral-wound construction for optimum energy transfer and durability
• 40 ohms resistance per foot — spiral-wound nickel/copper alloy conductor wrapped at the optimum ratio for maximum spark energy and minimum EMI/RFI interference
• Kevlar® core rated four times stronger than standard aramid fiber cores, delivering exceptional tensile strength and dielectric strength
• Extra-thick EPDM layer provides greater dielectric strength and UV resistance to resist cracking
• Closely woven fiberglass insulation impregnated with high-voltage leak-resistant silicone — adds up to 8,000 volts of additional insulation protection
• High-temperature silicone boots withstand heat up to 600°F, protecting against exhaust header heat, chafing, and contaminants
• Locking stainless steel terminals maintain a secure connection under high vibration and are fully compatible with Harley-Davidson ION sensing coils
• Made in the USA

The Moroso Ultra 40 wire set is a direct-fit upgrade for Harley-Davidson Softail, FXD Dyna, and FL models, replacing OEM wiring with race-level ignition performance. Whether you're building a performance machine or simply upgrading aging factory wires, the Ultra 40 delivers reliable, high-energy spark delivery in one of the most demanding ignition wire sets available.