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Cosmic Creation

Driving one of the most intriguing Japanese cars ever - the Eunos JC Cosmo 20B.

Words by Michael Knowling, Pix by Julian Edgar

Click on pics to view larger images

This article was first published in 2002.

The 20B twin-turbo triple-rotor is the motor every Wankel lover drools over - and from behind the wheel of a Eunos Cosmo it's easy to understand why. With no reciprocating mass, just three spinning rotors and two sequentially spinning turbos, the gangster-styled Cosmo thrusts forward as if somebody's strapped a jet turbine underneath. The mid-range is simply staggeringly good.

That Motor...

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Mazda went all-out with the development of the tripe-rotor twin-turbo. In addition to simply slapping another 654cc rotor chamber on the back of the 13B platform (bringing the capacity out to 2.0-litres), Mazda tested and tuned a complex sequential twin-turbo arrangement. With the primary turbo configured to give good throttle sensitivity and deliver boost from barely above idle, a secondary turbo chimes in to add manifold flow over about 4000 rpm. The end result is an engine that flexes some serious muscle from about 1800 rpm all the way to the 7000 rpm redline. Over 390Nm is available from around 2200 rpm and peak torque - a substantial 402Nm - arrives at 3500 rpm. A politically-correct 206kW is generated at 6500 rpm, though that figure is a bit rubbery - word is maximum power is closer to 220kW (when running on Japanese 100-octane fuel).

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Even during normal driving, when the throttle isn't fully open, the Cosmo's 'triple treat' still pushes out an awesome amount of torque. It feels like there's a monster big-cube engine lurking under the lid. And - unlike a current model Subaru Liberty B4 - it has the transitional turbo stage very well ironed out. There's no drop in torque while the second turbo is being phased into action.

Intended as a luxury sports coupe, the Cosmo comes with a standard triple-mode 4-speed automatic transmission. Shifts are positive and a handy 'Sport' mode - which locks out overdrive - ensures the engine is always ready-and-waiting to instantly deliver the goods. The rear-end reduces driveline rotational speed by a ratio of 3.909:1 and features a viscous limited slip centre - what else would you expect with an easy 206kW on tap?

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Despite having a standard automatic transmission and weighing between 1570 and 1640kg (depending on spec), the 20B Cosmo hauls its rump along very swiftly, thanks very much. After an initial hesitation off the line, the Cosmo can rip to 100 km/h in a brisling 6-ish seconds and cover the quarter in about 14.1 seconds. Terminal speed over the quarter is around 165-170 km/h - just shy of the Japanese-regulation 180 km/h speed limiter. Fuel consumption is likely to be equally rapid.

The very strong performance is a touch incongruous given the Cosmo's sedate lines. In fact, from some angles it almost looks a bit mid-Eighties 929 two-door. But it sure as hell doesn't go like an old 929....

What About The Corners?

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Not nearly as impressive as the engine is the Cosmo's rear-drive chassis. Note, however, there are two different suspension tunes on offer - the cushy-riding Type E (Elegance) model and the firmer Type S (Sports). Both share the same design - a double wishbone front-end and a multi-link rear with dual shocks per corner.

The soft suspension fitted to our test Type E.CCS made the car feel like a bowl of jelly. Boot the thing hard from low speed and the back end squats dramatically - anti-squat obviously wasn't high on the engineers' list of priorities. It also wallows and lurches when being pushed around corners, though it does remain reasonably stable. We get the feeling, however, that with this much power and this soft a suspension, it's a car you could have a major lose in. If you want to tackle corners at high speed, the firmer suspended Type S Cosmo is apparently a much more rewarding vehicle.

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Steering from the power assisted rack-and-pinion set-up is light but nicely linear. Oddly enough, Eunos 'did the cheap' in the braking department. Anti-lock single-pot calipers and ventilated discs - Mazda Astina V6 size at the front and late-929 size at the rear - struggle to manage the Cosmo's mass and accelerative urgency. Standard rolling stock on the luxury-spec Type E Cosmo are 15-inch alloys with 215/60 rubber, while the sportier Type S gets 16-inch alloys and 225/50 tyres.

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The Cosmo is a ponderously large car considering it's only - realistically - a 2-seater. It claims 1795mm of a lane width, the long snout stretches the car's overall length to 4815mm and it cheats aerodynamic co-efficiency with a 1305mm height. Its styling is unlikely to offend anyone - it's very much early '90s plain and smooth panels with sleek headlights and taught buttocks. There are no spoilers to detract from the simple lines. Paint and assembly is to a high standard.

Opulence in Abundance

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Despite its size, the Mazda is very tight for interior space. In the front, the tailshaft tunnel is very obtrusive, though there are still adequate amounts of head, shoulder and feet room. Access is made easier thanks to a steering column that tilts up when the key is removed from the ignition. The back seat is another story. There's minimal access, minimal headroom and - depending on front seat position - zero leg or feet room.

Even a desperate hitchhiker would turn down a free ride in the back of a Cosmo...

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The interior design is very elaborate - it's straight out of the most obscure Italian sportscar you can think of. The trims are heavily sculpted, the dashboard houses Honda Prelude-ish wide-view back-lit instruments and the steering wheel is completely out of this world. It contains controls for demist, air recirculate, climate control, cruise control, audio system and phone (which was offered as an option in the top-line model). Never before has the humble steering wheel been so complex - the only thing it doesn't have is an airbag.

The Cosmo interior comes in four luxury levels - Type S, Type SX, Type E Midrange and Type E.CCS.

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The Type S - the most basic - gets fabric trim, electric seats, push button climate control and ventilation, power windows and mirrors, trip computer, an AM/FM cassette and optional CD. A slight step up is the later Type SX (Sport Extra). This adds a combination of leather and fabric trim to the basic Type S formula.

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Absolute top of the Cosmo range is the Type E.CCS (Car Control System), which comes with full leather and a central touch screen to control everything from a 6-speaker sound system, ventilation, climate and demister. The screen is also used to talk to a global positioning system. The early Type E Midrange offers everything except for the CCS touch screen. It replaces this with a single tuner/cassette/single CD and push-button climate control and ventilation.

Buyers' Guide

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The first JC Cosmos (dubbed the Series 1) were released in April 1990. There were three spec levels initially on offer - the Type S (with firm suspension, 16s and 'base' trim), the Type E Midrange and Type E.CCS. These were the big-yen luxury floaters.

A subtle update - now known as the Series 2 - was carried out in '93. The update saw the headlights slightly altered, a few exterior colours were dropped, the top-line Type E.CCS received heated mirrors, trim was changed slightly and the 20B motor copped beefier rotor plates. Interestingly, the Type E Midrange was dropped from the line-up and the Type S became the slightly more up-spec Type SX (Sport Extra).

The entire Cosmo line-up was axed in late '95, with the very last vehicles sold during '96.

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Only around 9000 Cosmos were built during its 5-year lifespan. This is largely because it was tremendously expensive - a Type E.CCS cost 6 million yen in 1990, which is around the same price as a current Nissan Skyline GT-R...

Today, however, you can pick up your own second-hand Japanese import 20B Cosmo that's fully ADR'd and ready-to-go for around $25,000-ish. Sydney's DMRH - an approved Cosmo compliance agent - supplied our test vehicle, which was a 30,000 kilometre Type E.CCS, which (due to its low kilometres) is expected to be sold for $33,000.

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DMRH stock a range of second-hand spare parts and can access new parts directly from Japan. Some parts - such as the diff centre - are interchangeable with the local Series 6 RX-7 and the brakes share many components to local Mazda models. However, the Cosmo would be much harder to find parts for than many other run-of-the-mill Japanese imports. There's also lots of stuff that might one-day decide to call it quits - from the tilt steering column to the touch screen to the digital dash, it's a very complex machine. Accordingly, potential buyers should be sure to have a Cosmo thoroughly inspected prior to purchase.

The 13B Cosmo Option

About 40 percent of all Cosmos come powered by a sequentially turbocharged 2-rotor 13B. Although lacking the raw brute of the 20B, the 13B motor is rated at 172kW and 294Nm and can propel the Cosmo over the quarter in 15.3 seconds. Not bad at all.

A 13B Cosmo sells for around $17,000 - 25,000.


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Rip off the standard exhaust, bung on a couple of high-flow cold-air intakes and the Cosmo will give you around 15 percent more power without placing too much stress on its driveline. The next obvious areas for improvement are the intercooler and increased boost. Replace the factory air-to-air intercooler with something much larger and tweak the boost to - say - 14 psi (up from the standard 8.5 psi max figure) and you'll have a very tough street performer. Expect to enjoy around 30 percent more power and all the driveability of the standard car. Not too many cars would be able to stay alongside its door handles.

As mentioned, the standard brakes are not up to the performance of the rest of the car. Series 6 RX-7 anchors will certainly go on, however - keep in contact with DMRH for an up-coming kit. David of DMRH also tells us manual gearbox conversion - using either a Mazda or a Tremec 5-speed - is also not too far off.

There's big potential lurking in the Cosmo. Of course, even in standard form it'll blow most other streetcars into space...


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