Engine

Active filters
- Bolt-on power: +40–50% on stock 107", 114" and 117" M‑Eight motors.
- Compressor and turbine housing with Garrett internals; plenum with integrated blow-off valve.
- Includes injectors, spark plugs, boost gauge with mount, oil feed/drain lines, custom cam cover, tune files, hardware and gaskets.
- Requires Thundermax ECM (sold separately). Does not fit Twin Cooled or non-removable fairing lowers. Offroad use only.
- Made in the USA.
Transparent cam cover that matches Assault series air cleaners and allows internal inspection. Made in the USA.
Transparent cover for viewing internal engine components. Matches the Assault series air cleaners. Made in the USA.
Transparent cover for viewing internal engine components; matches Assault series air cleaners. Made in the USA.
State-of-the-art compression release valves that reduce hot starts and lower starter and battery loads. Sold as a set and made in the U.S.A.
State-of-the-art design to reduce hot starts and starter/battery loads. Custom molded knobs, sold in pairs, made in the U.S.A.
Designed for HD® Evolution OEM replacement. Machined from high‑grade metal with a corrosion‑resistant dark finish. Multipurpose alignment pins. Made in the USA.
PTFE valve guide seals with twin-spring tension for reduced friction and reliable valve control. Made in USA.
- Precision-machined bronze construction for durability
- Tapered nose to reduce port obstruction and improve flow
- Compatible with unleaded fuel and a range of valve‑stem materials
- Accepts top‑hat valve seals (sold separately)
- Made in the USA
Precision-machined valve guide accepts special seals and works with no-lead fuel; made in the U.S.A.