BMW S65 Carbon Fiber Plenum – Form, Function, and Sound Perfected

The Partee Racing carbon fiber plenum for the BMW S65 engine is more than a showpiece; it is a functional work of art. Constructed from multiple layers of pre-preg carbon fiber and cured in an autoclave, every plenum is handcrafted for exceptional strength, finish quality, and precision fitment. Each unit features custom billet fittings machined in-house and is available in a standard high-gloss finish, with optional matte or “show” finishes upon request.

Designed for Performance and Precision

This plenum is not only about looks. By removing the restrictive topside ribs found on the factory plenum, we increased internal air volume and created a smoother flow path. This design improvement enhances breathing efficiency and allows the included billet straight velocity stacks to perform at their full potential. The result is a cleaner, more efficient intake charge with measurable power gains.

Proven Results on the Dyno

On our in-house Dynojet XLC424, multiple back-to-back tests showed a consistent increase of 10 ft-lbs of torque below the 5250 RPM crossover point and a noticeably smoother, more linear torque curve when compared to the stock plenum. All tests were performed on the same car, same day, and same dyno to ensure accuracy. With custom tuning and an upgraded engine, these gains can be even greater.

Built for Enthusiasts

Beyond performance, the Partee Racing S65 Carbon Fiber Plenum delivers an intoxicating intake sound and a level of craftsmanship that transforms the engine bay into a statement of both power and design. This plenum is designed for discerning builders who appreciate performance without compromise.

Note: The plenum is not compatible with Turner Motorsport hybrid billet motor mounts, as they raise the engine height and may cause contact with the hood.