In celebration of its 50th anniversary, Mercury Racing revealed the new 500R outboard and two drives for the V8 package during a gala event on Wednesday in Charleston, South Carolina.
By Gregg Mansfield
The supercharged 500-hp outboard marks Mercury Racing’s second major product launch this year, following the debut of the 400R V10 outboard at the 2023 Miami International Boat Show.
After more than three years in development, the 500R comes equipped with numerous new features, including a redesigned crankshaft, a sturdier midsection, and humidity compensation technology.
“We’re incredibly proud of this flagship model. With our two normally aspirated engines (the 300R and 400R), the step up to the 500R delivers supercharged performance,” said Stuart Halley, general manager of Mercury Racing, after the introduction of the new outboard. “We required a new gearcase, our team accepted the challenge, and they developed the R-Drive.”
The gala drew notable figures from the high-performance boating industry. Celebrated attendees at the Mercury Racing event included industry icons such as Peter Hledin of Skater Powerboats, John Cosker from Mystic Powerboats, Randy Scism of Marine Technology, and John Tomlinson from TNT Custom Marine.
West Coast builders represented included Jake Fraleigh of Eliminator Boats and Jeff Johnston and Tony Chiaramonte from DCB Racing.
According to Mercury Racing, the 500R produces over 500 horsepower, which is 50 more than the 450R model and delivers 10 percent more torque. Its 4.6-liter 64-degree V8 FourStroke powerhead is enhanced by a supercharger from Mercury Racing, and it runs on at least 89-octane fuel.
To manage this power, upgrades were made to the powerhead, cooling system, midsection, and steering system. Engineers created a new gearcase specifically for the 500R, called the R-Drive.
The R-Drive, available in both base and sport configurations, features a crescent-shaped leading edge and a long aspect torpedo that is hydrodynamically optimized for high speeds, according to Mercury Racing. The new 5.9-inch gearcase accommodates propellers up to 17 inches in diameter, one inch larger than the 450R gearcase. Both drives are designed for semi-surfacing or full-surfacing applications with a 1:60:1 gear ratio.
“This gearcase was completely designed from scratch specifically for this product,” stated Chris Jenks, Mercury Racing’s technical development manager for the 500R. “It features a larger input shaft, a larger prop shaft, and larger internal components and bearings. We concentrated on optimizing water pickups and hydrodynamics.”
The 500R boasts the first humidity compensation technology for a marine engine. A new sensor integrated into the intake attenuator gauges the humidity of incoming air. This data allows the engine’s ECM to synchronize reported humidity with air pressure and temperature, calculating optimal spark timing for current conditions.
According to Mercury Racing, boaters will experience a notable power increase in humid conditions. This technology can contribute an additional 30 horsepower that typically would be lost due to high humidity.
The 500R is tailored for catamarans, center consoles, and pontoon boats and includes a three-year warranty. While the industry anticipated a 500-hp outboard debut at the Mercury Racing gala in Charleston, many were surprised that it was derived from a V8 platform rather than the V10 platform of the 400R introduced in Miami.
Halley indicated that planning for the 500R began post-2019 following the release of the 400R, which is based on a V8 platform. Mercury Racing now provides six outboards ranging from 60 to 500 horsepower.
“There were elements considered during the 450R development that could not be implemented at that time,” Halley remarked. “We always understood a sequel was in the works.”
