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.
Includes top and second compression rings plus three-piece oil control rings; supplies enough rings for two pistons for reliable sealing and oil control.
Complete replacement ring set with top and second compression rings plus three-piece oil control rings. Restores compression, controls oil, and improves oil economy. Includes enough rings for two pistons. Made in the USA.
Complete set of top, second, and three-piece oil control rings for two pistons. Barrel face top rings and Napier second rings provide improved sealing and heat transfer; three-piece Flex Vent oil rings ensure positive oil control. Made in the USA.
Complete replacement piston ring set with PVD coating: barrel face top rings, Napier second rings, and three‑piece flex vent oil control rings. Includes enough rings for two pistons.
Complete mounting kit with all required hardware for inner primary installation. Made in the USA.
Plug and plug kits for various Harley‑Davidson oil systems; includes washers or O‑rings as required. Made in the U.S.A.
Heat-treated, plated adjuster bolts with included chrome lock nuts. Made in the USA.
Durable button-head Allen drain screws with copper compression washers for fork sliders.
Stem bolt with washer; complete hardware kit, made in the U.S.A.