Tokyo 2009: Mazda RX-500 still awesome nearly 40 years later
1970 Mazda RX-500 Concept - Click above for high-res image gallery
One of the coolest concept cars here at the Tokyo Motor Show isn't even new. In fact, it's almost forty years old. Originally displayed at the Tokyo show in 1970, this Mazda RX-500 Concept features styling similar to the legendary Ferrari 250 GTO Breadvan, gullwing doors that swing forward, and a 491cc rotary engine just behind the seats. Weighing in at just 1873 pounds, the 247-horsepower concept was said to have reached nearly 150 mph on Mazda's test track.
The car was recently restored in partnership with the Hiroshima City Transportation Museum where it has apparently been on display for the last year. Lucky for us, they decided to bring it to the show for us to enjoy as well. Check out this unique bit of retro-conceptual genius in our high-res gallery below.
Photos copyright ©2009 Drew Phillips / Weblogs, Inc.
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Reader Comments (Page 1 of 2)
mk15 10:24AM (10/22/2009)
Looking at the rear, I'm sort of expecting flames to roar out like a fighter jet's when they start up the car.
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kaslings 10:33AM (10/22/2009)
that is AWESOME. it looks like a fairly big car to only weigh 1800 lbs. so cool.
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Sofa King Fast! 11:39AM (10/22/2009)
I was thinking the same thing- how does that thing weigh just 1800 lbs?
Dondonel 11:54AM (10/22/2009)
These 60s and 70s lightweight specials had fiberglass body over backbone chassis. They are extremely light, drive well, but offer very little protection to the driver (usually they have only a basic roll bar).
Alex 10:32AM (10/22/2009)
i love those old wheels.
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paul 11:17AM (10/22/2009)
Exactly the same thought I had when looking at them. They are so simple and clean looking compared to today's overdone wheels.
Paul
Marcello 10:33AM (10/22/2009)
BEAUTIFUL!!! Old school rotaries rock my world!
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Luso 10:35AM (10/22/2009)
Old school "Dogs Bo11ocks"!
Now that's a nice piece of car.
http://www.carnorama.com
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turbo-quattro 10:54AM (10/22/2009)
want!
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David 10:59AM (10/22/2009)
Seriously, that car wouldn't look entirely out of place on display at a modern auto show. I like it!
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louisnoa 11:04AM (10/22/2009)
That is one small rotary engine. Is that power figure accurate?
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Marcello 11:17AM (10/22/2009)
from reading other sources on this car they all register the 10A rotary engine to have about 247hp. How they did that I am not entirely sure. There has to be some huge porting done to the engine I bet. Also i would not be surprised it they added some forced induction as well. Either way about 250hp out of a 10A engine is F**king incredible!
montoym 11:59AM (10/22/2009)
It will also depend on how many rotors the engine has. The way they measure rotary engines, the displacement cannot be directly compared to piston engines because they only account for the displacement of a single rotor face. That's similar to only counting the displacement of a single cylinder in your car and marketing that as the displacement.
Here's more info about how they measure displacement on rotaries and what needs to be done to compare it to a piston engine.
http://en.wikipedia.org/wiki/Pistonless_rotary_engine#Comparisons
Marcello 12:09PM (10/22/2009)
@ montoym:
the 10A engine in this concept is a twin rotor design. The thing that is crazy is that NA two rotor engines do not produce alot of HP in stock form. These engines need to have huge portings done to the housings to get alot HP out of them......and considering that this 10A engine is a small engine to begin with (i think in stock form the 10A got like 100hp from the factory) this concept having 247hp from that 10A is amazing!
montoym 12:14PM (10/22/2009)
Did some more quick research, appears that the 10A is a 2-rotor design.
Using the displacement calculation approach in my previous comment above, this engine would be equivalent to a roughly 2.0L piston engine.
Considering that the turbo 13B in the 3rd-gen RX-7 displaced 654cc on a single rotor face and produced up to 280hp(officially, wink wink), I think it's a safe bet that the 10A had the help of forced induction. Especially cosidering it came out a few decades earlier.
Nateb123 1:39PM (10/22/2009)
Yeah, it's 654cc per rotor face but that's a bit misleading. When you factor in the frequency of a spark in terms of revolutions of the crank/output shaft and how a piston engine's displacement is calculated, you find this:
The e-shaft turns 3 times faster than the rotor, this means 1 rotor face experiences a combustion cycle per output shaft rotation or 2 e-shaft rotations=2 combustion cycles. For a piston engine each cylinder gets a spark every 2 crank rotations so 4 cylinders would be required for there to be 4 sparks per 2 crank rotations.
Now a piston engine has displacement calculated by using the swept volume of the piston. So despite having to go up and down that same displacement of say .25L twice, that piston still is said to displace .25L. So to count a rotary's displacement you count two faces as only two faces of each rotor will experience a spark over 2 rotations. So a 13B is a 2.6L engine.
As for the engine in this car, is it a 10A? I can't find if it's 1 or 2 rotor, turboed or not, nothing.
MDX 11:21AM (10/22/2009)
Looks like ARK II.
Good looking anyway, the coolest thing for it's time.
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MrLlamaLlama 11:22AM (10/22/2009)
Utter beauty. It's so fantastically boyish and spaceship- like. I'm a huge sucker for the flat - back aswell (love my early 90's CR-X Hondas! )
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Shiftright 11:27AM (10/22/2009)
Soo-eet! I just bought a detailed scale model of the black and yellow version last week!
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imoore 12:12PM (10/22/2009)
Is it the model produced by Matchbox in the '70's? I still have the one I bought back then and found another one last year at a yard sale. You can't beat the old "Leaney-Made in England" models.