New Mercury Racing R-Drive and R-Drive Sport Gearcase Designed for Extreme Power and Speed
Optimizing the performance of the new Mercury Racing V8 500R outboard required development of a number of new components to complement the incredible power of its supercharged 4.6-liter V8 engine. The all-new R-Drive gearcase, available in R-Drive and R-Drive Sport configurations, is designed specifically to complement the speed and power of the 500R outboard in submerged, semi-surfacing and full surfacing applications.
Both versions for the R-Drive gearcase feature a similar crescent leading edge and long aspect torpedo hydrodynamically tuned for high speeds. The new 5.9-inch gearcase is able to fit propellers up to 17 inches in diameter, one inch larger than the 450R gearcase. 
The R-Drive gearcase is designed to perform well in submerged and semi-surfacing applications, with a 1.60:1 gear ratio and a standard skeg length. The new skeg has a very efficient parabolic cross-section shape and is offered with left- or right-hand camber to balance steering force with standard and counter rotation props. This drive was engineered with low water pick-ups, a nose cap pick-up, and a torpedo shape to thrive in transition applications on boats capable of speeds between 85 and 100 mph, beyond the speed range of the Mercury Racing 5.44 HD gearcase. A new intermediate spray plate is designed to reduce drag in semi-surfacing applications, such as high-speed center console boats.
R-Drive Sport
The R-Drive Sport gearcase is intended for very high-speed surfacing applications, primarily high-performance catamarans and center
Nose Cone Pick-Up
Both versions of the gearcase incorporate a low water pickup under the front of the torpedo and a new adjustable nose pick-up to dial in ideal water flow for a specific application. The nose cones come in two basic shapes – one for submerged/semi-submerged applications which have several water inlet hole variations, and another that is shaped to run in surfacing applications. An all new water pump increases capacity 57 percent to ensure optimal flow to this high-performance engine.
Beefy Inside
For both gearcase models the driveshaft diameter is increased to 1 inch from 7/8 inch and the propshaft diameter is increased to 1.5 inches from 1.25 inches, compared to the gearcase options offered for the 450R. The R-Drive Sport gearcase is equipped with a propshaft made from an ultra-high-strength aerospace stainless steel alloy similar to the material used for the Mercury Racing M6 and M8 model sterndrive propshaft, selected specifically to better endure the vibratory stress caused with the loading/unloading of a surfacing propeller.
The Mercury Racing 500R is covered by a three-year limited factory warranty with up to five additional years of Mercury Product Protection extended factory warranty available. Learn about the Mercury Racing Wide Open lifestyle and all Mercury Racing high-performance products at Mercuryracing.com.
LEARN MORE: Mercury Racing Advanced Racing Core (ARC) midsection is the strongest, stiffest and most-durable midsection ever created by Mercury Racing.
