Engine

Active filters
Compact universal fitting for joining flare and threaded connections. Easy install and durable performance.
- 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.
Designed for twin plug heads. Accepts .650"/10mm x 1.0 compression release valves. Sold each.
High-performance camshaft with Endurance Ramps for broad torque, reduced valve train noise, and billet steel construction.
Forged performance replacement for stock hydraulic roller lifters. 100% tested and made in the U.S.A.
Adjustable front stabilizer link for HD Touring frames with reverse-thread rod end and ARP stainless bolts; available in black anodized, gold anodized, or machined finish. Made in the USA.
Mounts S&S E/G or Keihin CV style air cleaners to Mikuni HSR 42/45 carburetors. Made in the USA.