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.
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 Change gears 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.
Entering the water can be done at speeds up to 15 mph (24 km/h) if there is no step higher than about six inches (15 cm) and the beach is sufficiently firm. Some spectacular entries and exits from the water appear on the video below. Once in the water, the pilot places the four-speed in neutral, pulls a knob to switch the transfer case over to jet drive, pushes a knob to hydraulically lift the wheels and tires out of the water, and start boating. The entire procedure takes less than 15 seconds.
Once in the water, the Panther is remarkably stable for a boat that is only 15 ft (4.6 m) in length. It leans a bit in tight turns, but makes the most of the low center of gravity resulting from having both automotive and marine drive systems. This also renders the Panther a bit reluctant to get out of the hole to planing speed, but the amphib appears to handle well at its top speed of nearly 45 mph (72 km/h).