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Auto Shows
Date Posted 03-29-2001
Mazda RX-8
Video highlights of this vehicle
What is it?
Mazda RX-8
What's special about it?
Telling us it's closer to production than its RX-EVOLV predecessor shown
at last year's Detroit show, Mazda's rear-wheel-drive RX-8 "design engineering
model," is powered by a 1.3-liter (80 cubic inches) 250-horsepower rotary engine
such as what was found in the RX-7 last sold here in 1995.
However, the RENESIS (derived from the word "genesis") engine is a new type
of rotary with several technical advancements over the one in the RX-7. The
RENESIS actually makes almost as much power as the turbocharged engine in the
RX-7, while offering improved emissions, better fuel economy and 30 percent
less weight.
Unlike previous rotaries, which used side exhaust ports and peripheral intake
ports, the naturally aspirated RENESIS has intake and exhaust ports in the side
housings. This configuration eliminates overlap between the opening of the intake
and exhaust ports, thus improving combustion efficiency. The intake ports are
also 30 percent bigger and timing has been changed to make them open sooner.
Furthermore, the exhaust ports open later, resulting in a longer power stroke
and improved heat efficiency. The new engine also has lighter rotors that weigh
14 percent less than those in the RX-7 engine. The engine is backed by a six-speed
transmission with, as Mazda calls it, auto/manual shift.
There's much more, however, to the RX-8 than just its significantly updated
rotary powerplant. Body packaging on the car is enhanced by the fact that the
new engine is not as tall as the earlier rotary. About the same height as the
transmission, the compact engine allows it to be mounted near the center of
the body, 60 mm closer to the center than in an RX-7, resulting in a central
front mid-ship layout and a 50/50 weight distribution.
The overall structure of the RX-8 is equally innovative. By positioning the
powertrain lower, Mazda was able to improve rigidity by locating a high-mount
backbone frame on the upper part of the tunnel. This frame connects the front
and rear bulkheads through the inner center and strengthens body rigidity. It
also plays a part as a main body frame to reduce thickness of the body panels
for less weight.
The RX-8 has a double wishbone suspension at all four corners. The upper and
lower arms in both the front and rear are considerably longer than those on
the RX-7, which keeps the tires gripping the road against changes of roll and
camber, providing a smooth roll center and top-notch cornering performance.
Probably the most unusual aspect of the "8" is its four-door bodystyle and space
for four. Large door openings and a center pillar-less design allow easy access
to the backseat. The car also has lots of luggage space due to the rear suspension's
springs that are positioned lower and close to the lower control arms.
Why should you care?
Mazda will be back in the sports car game with the RX-8, even though it's
much different than the RX-7. And with the new RENESIS engine making 250 naturally
aspirated horsepower compared to the RX-7's 255-horsepower twin-turbo
motor, it'll be a thrill ride indeed. Imagine if Mazda hangs a pair of hairdryers
on this one?
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