Recreational amphibious vehicles are nothing new, but most are one-offs and most tend to be boats that can creep on land, or cars that slosh slowly through water. There are exceptions, notably entries from Gibbs, but arguably, amphibious vehicles have not made the grade as true all-round vehicles that can be driven to work during the week, and on the lake on weekends. WaterCar's new Panther straddles the divide.
Take a Jeep CJ-8, put a Honda Acura 3.7-liter V6 in the back to provide 305 hp, add a fiberglass hull, retracting wheels, and a jet boat drive and you've got the new Panther from WaterCar, which it claims is the world's fastest amphibious car. Capable of doing over 80 mph (127 km/h) on the road and 44 mph (70 km/h) on the water, the Panther is equipped with a long-travel off-road suspension that allows access to less user-friendly lakes. The appearance of the Panther takes after the Jeep CJ-8 Scrambler, with a stretched wheelbase that provides extra interior room.
Because the Jeep chassis proved too heavy, so WaterCar designed a lightweight chassis made of chromoly steel. Having properties (weldability, formability, strength, ductility and toughness) that greatly exceed those of regular carbon steel, the choice of chromoly steel, while pricey, solved the Panther's weight problem.
The Panther's chassis was designed to slip neatly into a fiberglass hull, and is secured therein by modern epoxies, thereby reducing noise and shimmy during hard handling. The hull and chassis incorporate advanced composites where extra strength and toughness is required, and the hull is filled with closed-cell styrofoam, rendering the Panther nearly unsinkable.
What goes inside the hull and chassis includes a powerful powertrain that provides motive force both on land and water. The engine for the Panther is the latest-generation Acura 3.7-liter VTEC V-6 engine. An all-aluminum powerplant, the V-6 is equipped with single overhead camshaft cylinder heads and 24 valves. Both intake and exhaust valves are controlled by Acura's Variable valve Timing and lift Electronic Control (VTEC) system.
This 3.7-liter engine is a bored and stroked version of the Acura 3.5-liter engine. As this left little clearance between the cylinders, the cast-in iron cylinder liners of the 3.5 liter were replaced by high-silicon aluminum liners. This results in better cooling and tighter piston ring seals. The compact and efficient 3.7-liter engine produces 305 horsepower at 6,300 rpm with special emphasis on mid-range torque giving this VTEC a peak torque of 274 lb-ft (371 Nm) at 4,500 rpm.
The Panther uses WaterCar's own transfer case with Winter's Quick Changegears and components to transfer power between a model 091 VW Vanagon bus four-speed manual transaxle driving the rear wheels, and the H450 Panther Jet drive. WaterCar's transfer case is rated at 1,000 hp, so should have a long service life in the Panther. The H450 Panther Jet drive is rated to 500 hp input.
Enough tech specs – how does the Panther perform? On the road the Panther is capable of a maximum speed somewhere north of 80 mph (128 km/h). Acceleration times are not yet available, but with 305 hp (232 kW) driving a car weighing just under 3,000 lb (1,340 kg), it is reasonable to expect snappy, if not extreme, acceleration. The VTEC engine has a compression ratio of 11.1:1, and requires 91-octane premium gasoline to avoid detonation.