Turbocharged Cordia joins sporty Celeste from Mitsubishi

Press, 25 February 1983, Page 25

Turbocharged Cordia joins sporty Celeste from Mitsubishi

BEHIND the WHEEL with

Peter Greenslade

Although turbocharged diesel engines have been a feature of the heavy transport industry for a long time, forced induction for petrol engines by this method is a relatively recent development. It is' one of the byproducts of the oil crises of the last decade or so, for turbocharging is seen at present as being the simplest method ,of obtaining a quart from a pint pot.

Mitsubishi now has a turbo version of every car it produces and Mitsubishi Heavy Industries have been developing and producing turbochargers for more than a decade. That is not really surprising, for not only has Mitsubishi an exceptionally strong background in aviation and marine engineering, but it is also the manufacturer of a very wide range of diesel-powered buses, trucks and special-purpose vehicles.

New Zealand’s Mitsubishi importer and assembler, Todd Motors, Ltd. will publicly introduce the Cordia. the Mitsubishi replacement for the sporty Celeste, on Monday. The Cordia is a slickly styled 1.6-litre, front-wheel-drive, two-door sporting hatchback built on the same floor pan as the similarly powered and driven Mitsubishi Tredia saloon, introduced towards the end of last year.

In introducing the Cordia, Todd Motors has also taken the opportunity to lauch top-of-the-line turbocharged versions of the Cordia and the Tredia. These are the first locally-assembled cars to appear with totally integrated engine-turbocharger packages. and ancillary equipment designed to cope with the substantially increased power the packages provide.

For example, although the normally-aspirated Cordia and Tredia share the 4G32 four-cylinder overhead camshaft engine with the turbo versions, the latter are fitted with larger air cleaners and larger inlet manifolds. The manifolds contain the turbo unit which, unlike most bolton turbos sold as extras, is located between the carburettor and the engine.

The Mitsubishi system draws a large volume of air

at atmospheric pressure through the carburettor, compresses the fuel-air mixture and forces it into the engine. The turbo, driven by exhaust gases, starts to flex its muscles at about 2000 r.p.m. and shows its strength in no uncertain fashion from an engine speed of about 3000 r.p.m. Power lag, normally associated with turbocharging, is minimised by locating the carburettor close to the inlet ports, this being achieved by bringing the exhaust manifold around the side of the engine and through the turbo unit.

The control system, required to make the turbo operate efficiently and to ensure that it does not exceed its maximum design speed of 175,000 r.p.m., is less evident. It includes a waste gate, boost control, vacuum switch and ’ control unit, knock sensor and engine spark control. This control system enables the standard compression ratio of 8.5 to 1 to be maintained in the interests of optimum low speed performance. Inside the engine itself there is a heat-treated crankshaft to cope with the greater loads and stronger pistons fitted with hard chrome-plated rings. A heavy duty radiator has a capacity almost 150 per cent greater than the standard version. There is also a thermostatic fan and an oil cooler.

An electromagnetic fuel pump replaces the standard mechanical pump and stronger body cross-mem-bers are used to increase the rigidity of the engine mounts. To give handling that is compatible with the improved performance of the turbo cars, the half shafts have been modified and the rack and pinion steering has been geared to swing the car from lock to lock with 3.6 turns of the steering wheel rather than 4.2 turns.

Also, firmer springs, a rear stabiliser bar and stiffer gas-filled shock absorbers have been fitted.

Turbocharging increases the power output from the standard 55 kW to 84 kW (112.6 b.h.p.) and to cope with that a brake booster with a diameter of 203 mm, instead of 178 mm, is fitted, along with ventilated front disc brakes.

The mechanical specifications of the turbocharged versions differ widely from those of the normally-aspi-rated Cordia and Tredia and this is reflected in their prices. The Cordia GSR Turbo retails for $18,168, compared with $15,168 fpr the “unblown" version which is also fitted with Mitsubishi’s Super Shift 4-speed x 2 transmission system. Similarly, the Tredia GSR Turbo, at $17,830, costs $3OOO more than the comparable norm-ally-aspirated car.. In deference to the Minis-

try of Transport, motoring writers sampled the Cordias and the Tredias on the rather tight Manfeild motor racing circuit at Feilding earlier this month. A race track is not the best place at which to appraise a road car, although it does enable one to assess the absolute parameters of handling capabilities and the effectiveness of brakes, as well as a car's ability to accelerate, without causing any concern to public road users. I found that the Cordia possessed almost neutral steering, there being only a trace of understeer, the common characteristic of frontdrive cars, and almost no front-wheel-drive feedback through the steering. The brakes proved to be up to their job; there was little sign of fade in nearracing conditions, although there was considerable heat build-up. Mitsubishi claims that the Cordia Turbo will accelerate from rest to 96.5 km/h in 9s and one did not have to treat it brutally to get within fractions of the claimed figure. Top speed is claimed to be just on 190 km/h (118 m.p.h.), but Manfield’s straights were far too short for verification of the figure and I certainly did not see more than 150* km/h on the speedometer before braking heavily for the bends out of the two straights.

As I drove the Cordia Turbo before the normallyaspirated version, I found the latter to be a somewhat docile beast. It is, however, a very sprightly 1600 cu cm car and superior in every way to the similarly sized Celeste which it replaces. These cars are tastefully and practically appointed. The individual front seats are generously proportioned and have a good range of adjustment. There is good leg-room in the rear compartment although, perhaps, taller folk would be happier with more head room. Access to the rear compartment through the wide doors

is about as good as one would expect in the case of a two-door coupe. I was particularly impressed with the upholstery — a heavy-duty tweed of discreet check with a colourkeyed stripe in it. However, the trim was not up to the usually high standards of Todd Motors, particularly around the door openings. The instrument panel contains everything that the most discerning owner would demand, the instruments being back-lit in orange. Conspicuous by its absence is a turbo boost gauge, but as the whole turbo system is electronically controlled, and boost pressure is limited to a comparatively lowly 7 p.s.i.. a gauge is not necessary. This is perhaps the appropriate place to mention that the turbocharger requires no maintenance, being, to all intents and purposes, a sealed-for-life unit. However, it should be treated with respect. In other words, it is wise to allow a few seconds to elapse to enable reasonable engine warm-up before making big demands on the car and also to let the engine idle or at least run at modest speed before switching off. After spending the day on the race track mainly with the Cordias, I was fortunate enough to return to Wellington in the turbocharged Tredia. This is a surprisingly flexible and responsive family saloon and I found that it had sufficient power to drive very comfortably in the Super Shift’s long-legged set of ecomony ratios on the open road. In short, it feels like a car with a 2.6, rather than a 1.6litre engine and I’ve no doubt that, driven in a sensible fashion, it would return petrol consumption figures that would be a constant source of delight to folk with I Shylock dispositions. ! The thing about these tur- j bocharged Mitsubishis is thatl they provide power on de-j mand to, for example, tow a s bigger boat or caravan safely, with adequate power and sufficient braking, without paying a penalty in fuel consumption during normal i motoring. Dynamometer i testing shows that these cars are the equal of the norm-ally-aspirated versions under the same driving conditions. Although the spectacular performance will impress the “go faster brigade" their real merit lies in the fact that they will carry out the heavy duty work that in the past has been regarded as a task for cars of twice the engine capacity. What is equally important, they do the work economically.

Todd Motors and its dealer network are taking a bold step in introducing these cars at this time, when the market is in such a depressed state, but, no matter how you look at it. the GSR Turbo versions of the Tredia and Cordia are cars for our times.