UK Autotest - Colt Cordia Turbo (Page 1 of 3)

Article from UK Autocar Magazine dating back to 30 October 1982. Article supplied by Derk Henderson

Mitsubishi have put their faith in turbocharging as a means of improving the performance of their cars and the efficiency of their engines. Turbo Colts have been popping up thick and fast in recent years - the Lancer, Sapporo, the rather brutish Starion and more recently the 1400 GLX, also known as Mirage (Autotest 14 August, 1982), and now the Cordia, one of a pair of all-new Colts which have been available in Japan since the middle of the year but are launched in Britain this week at the Motor Show.

The Cordia features fastback, coupe styling, with a bustle tail; in general terms it contrives to look very much like any other Japanese coupe, with sloping grille flanked by slightly taller headlamps and wrap-round sidelights, thick pillars, high waistline and ugly faired-in plastic bumpers. Its sister car is the Tredia, which uses the same floor pan and has the same 96.3 in. wheelbase, but takes the form of a somewhat unobtrusive medium size booted saloon which competes with - and will presumably eventually replace Colt's own Lancer.

Mechanically the Cordia follows the pattern of the 1400 GLX with strut front suspension and separate anti-roll bars, and with Colt's unusual trailing link rear suspension in which one arm Pivots on the cross-tube of the other. There is also a rear anti-roll bar. Steering is rack and pinion, and there is 6mm of negative offset.

The engine is Colt's 1,597 c.c. G 32 single overhead camshaft unit, which in turbocharged form delivers an impressive 112 bhp (DIN) at 5,000 rpm and a remarkable 125 lb. ft. of torque at 3,500 rpm.

The Mitsubishi Heavy Industries TC-04 turbocharger as used in the Cordia has blades only 1.9in. in diameter, and it revs up to 90,000 rpm to give a boost pressure of about 8psi. The turbocharger sucks through the carburettor, rather than blowing through as on most other car installations.

Performance: What You'd Expect

The Cordia started immediately cold or hot, with no more than a mild hesitancy for a few minutes after driving away from cold on a chilly autumn morning. Response to the throttle is good while the car is being driven lightly, for example while easing through bustling early morning suburbia on the way to the open, road. However, when you need sharp, hard acceleration, such as when picking a way through stop-start commuter traffic or joining a busy highway from a side road, the Cordia's performance seems initially disappointing. A normal pull-away, starting with engine revs at around 2,000 rpm, flooring the throttle and dropping the clutch, doesn't work. Engine revs die and the car inches forward; a combination of low compression ratio and the lack of turbo boost at that engine speed. Disappointment vanishes when you learn to drive around the off-turbo flat spell - get the revs up to at least 3,500 before you drop the clutch and the Cordia - lurches off with a chirp of wheel spin. During our performance testing we found the best standing starts were achieved by dropping the clutch at 4,500 rpm in the low ratio and 5,500 rpm in the high ratio, to generate sufficient wheel spin to keep the turbo well on, and making changes at the red-lined 6,000 rpm mark holding more throttle than usual during the changes, again so as not to lose boost during acceleration.

That is a rather brutal way to treat a car, since it results in lots of driveline shudder, tramp from the front wheels followed by noisy wheel spin and quite a bit of engine noise. Fortunately it is not necessary to adopt this extreme procedure to achieve reasonably quick performance on public roads. While initial acceleration might be on the slow side, the turbo comes in with a will from 3,500 rpm onwards, giving a strong surge of acceleration.

In spite of the eight available forward speeds, the Cordia Turbo does not seem to have an ideal top gear. In fourth in the low range comes up just on the red line, indicating under gearing, while in fourth in the high range even the one-way best speed of 116 mph session comes up 400 rpm below the 5,500 rpm power peak, indicating a small degree of overdrive.

An examination of the eight available ratios shows an interesting overall progression from sportingly low to economically high, but it is not practicable to use all eight gears in order, because of the number of two- lever shifts that would require, with the additional problem that some of them would require the levers to be shifted in different directions.

We tended to use the range-change lever either as a sort of overdrive or as an alternative to the dog-leg change from third to second in fast cross-country motoring.

Starting in the low range allows more positive getaway, bearing in mind the engine's relative sluggishness at lower revs, and staying in the low range until fourth allows the quickest practical acceleration to cruising speeds. Then selecting high range offers a more economical top gear. If you need more revs for a corner, shift down to third, which gives a ratio close to the low range top. For a slower corner shift to low range, giving a ratio roughly half way between the high range second and third. a useful drop gained with a slick forward snick of the range-change lever instead of that awkward zigzag back to second.

If that lot sounds complicated don't worry about it. It is also feasible to think of the range change facility as providing two - separate gearboxes, low range for town use, high range for the open road. Either way it takes only minutes to become accustomed to using that second lever.

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