Mitsubishi Scorpion GJ/GK/GL

Introduction

The Mitsubishi Sigma Scorpion was originally released in 1977, and underwent several model updates and engine changes to keep it at the forefront of the then “under $10,000” coupe market. Here in Australia the Scorpion was released in March 1978 and had a sticker price of A$9800. As exchange rates moved the price was dropped to $8790. By the time the 2.6 litre version superseded the two litre, its introduction price was A$8990.

But the improved GJ saw the price drop even further - in five speed manual form with almost everything standard it had a sticker price of $9490 - $310 CHEAPER than the first two litre in 1978. The automatic cost a little more at $9990, but was fitted with variable ratio power assisted steering included in the price. The Scorpion was powered by Mitsubishi’s proven 2.6-litre 'Silent Shaft' four cylinder engine, never a motor to set the world on fire but a reliable and tractable unit that offered plenty of torque across the rev range.

But it was on the outside that the Scorpion differed from the run-of-the-mill 4 cylinder also-ran’s of the late 1970’s and early 1980’s. The 1981 GJ model, which featured a wedge-shaped nose and quad rectangular headlights. The front end treatment set it apart from its Sigma cousins, and the sheet metal from the windscreen/doors rearward was only for the Scorpion.

The new model had a revised grille featuring the tri-diamond Mitsubishi logo, while black finished exterior mirrors, new bumper stripes and a distinctive windshield moulding helped the car further distance itself from the Sigma. But the most important changes occurred inside the Scorpion. The original iteration offered less cabin, head, leg, knee, and shoulder room than the supposedly “lesser” Sigma cousins, and so the engineers set about a complete redesign of the interior, resulting in not only more space, but a much more efficient use of the available room.

By altering the car's styling, the chunky look of the GH gave way to a wedge shape that was undeniably more attractive and "international" in concept. It was a fuss free looking design that was more aerodynamically efficient. Few panels were carried over from the GH because of the designers requirement to increase internal space, height was up 25 mm, while the tumble home between waist line and roof was reduced to give better lateral head room. Leg room was been increased by extending the wheelbase a further 15 mm and by relocating the rear coil springs further back, thus reducing the intrusion of wheel arches into rear passenger space.

On the Inside

Rear passenger knee room was far better, while the wool cloth seats were more comfortable than before. This was achieved through the use of smaller front-wheel housings to provide greater front room, while the wheelbase was lengthened to allow the re-designed seats to be moved backward, thus allowing more leg room. A fractionally higher roof line and rear window helped add to the available head room (particularly for rear occupants), while modified door linings helped improve lateral shoulder space.Up front the driver's seat had squab angle adjustment, a feature missing from the GH line.

Even the position of the gear lever and handbrake were modified in an effort to increase driver comfort and control. Air-flow inside the cabin was improved and side window defrost outlets added to the control and end outlets on the dash. The fully carpeted boot was deeper and longer, and the boot lid leveled off, making for an increase of 17 per cent to 350 litres. Levers, floor mounted to the right of the driver's seat, looked after remote boot release and fuel filler cap flap, the latter being an innovation on the Scorpion. Thanks to the split lay down rear seat backrests, together with the higher boot lid, luggage space was greater by 50 litres. The boot was carpeted throughout, this, together with better sound deadening, contributing to the car's overall refinement. Interior storage space was reasonable, although the passenger side parcel shelf of the GH was deleted. In addition to the glove box, there was a centre console lidded bin and neat little pull out drawers under both front seats.

The GJ's interior was enhanced greatly by a completely revised facia and instrument design. Gone was the gimmicky single spoke steering wheel, replaced by a much better looking unit, complete with a thicker soft feel rim. Much lower than previously, the new facia added to the feeling of extra space. The instruments were contained in a separate binnacle, and grouped so that the driver's eyes didn't have to roam very far either from the vertical or longitudinal point of view. The cluster contained matching tacho and speedometer, flanked by fuel, water and oil pressure gauges along with a battery charge indicator.

The controls were very similar to the previous version, well placed for easy use. The multiplicity of driver's seat adjustment, combined with the steering column angle adjustment, made it almost impossible for any driver not to find a comfortable, safe, commanding position. Gone was the aircraft type roof mounted console. There was just a small bank of switches above the windshield to control a pair of map lights and an interior light. The centre console, finished in matt black, contained radio cassette player, heater controls and a neat ash tray. Driving controls were much as before, save that the parking brake – which was moved to the driver's side of the transmission tunnel from the top. Exterior rear vision mirrors were fitted to both sides and had remote control. A digital clock was mounted in the centre of the console just below the windshield.

Improved Visibility

Apart from the thick rear pillars, all round visibility was excellent. Even the rear pillars did not obscure much as they were set well forward. There was a little distortion through the radically curved section of the heated back light, where it took on the job of continuing rear body shape on the corners. But it was minimal. In the redesign, Mitsubishi took the opportunity to improve fresh air ventilation – as on the GJ many owners had complained that it was not up to an Aussie summer. These changes made the heater more effective too, giving a widespread flow of air throughout the car rather than barbecuing the front passenger's feet and leaving those at the rear shivering.

An attractive feature in the Scorpion's design was the ability to wind all side windows down – a rare feature on coupes from the era, and even today. In this “open pillarless” coupe form, passengers weren't blown about too much by the air stream, which said a lot for the aerodynamic efficiency of the body shape. With all windows up there was very little wind noise to be heard on the inside. The engine's smoothness, when linked through Mitsubishi's excellent five speed transmission made the whole car a delight to drive, especially under otherwise arduous city and suburban conditions. Efficiently located, the gear shift fell readily to hand, and its movement through the gate (using the standard H pattern for the lower four ratios, with fifth to the right and forward opposite reverse) was like the proverbial knife through butter.

The relationship between clutch and shifter was such that it encouraged gear changing too, just for that feeling of precision. Ratios were the same as the GH, with fifth representing a .856 overdrive. This dropped revs right back for effortless highway cruising, and could be used around town if you were not in a hurry. The Scorpions controls were wonderfully progressive, including the brake pedal. Whether used fiercely or gently, it provided the driver with confidence, and encouraged selective operation to provide the smoothest possible travel.

Front suspension, while still basically the same in layout to the GH, featured revised linear rate springing and shock absorbing, together with reduced steering scrub radius that came close to being neutral. This was aimed at improving straight line stability over rough going, although there were other mechanical features which conspired to negate any advantages in that direction. The steering was still, unfortunately, by recirculating ball – but with the addition of the anular bearing atop the sector shaft to allow more pre-load. It had a variable ratio which provided fairly stiff on-centre feel, with progressively weighted pressures as lock was applied – but it was way behind a rack-and-pinion setup. Another area where things conspired against the ultimate directional stability was the rear suspension.

The live axle was coil sprung with linear rate and located by what was close to semi trailing lower control arms with upper radius rods which were angled in towards the chassis. For the GJ with its revised spring position the lower control arms were redesigned with axle mountings to the rear of the axle tubes rather than to the front as in the GH. This allowed a larger radius through which the axle could move. By using more compliant rubber bushing in all the various attachments, however, some untoward axle movement was present. It didn’t affect the handling too much, but nearly every motoring journalist of the time noted that the system did not exactly inspire confidence either.

Axle movement in the lateral plane could be felt to a small extent, which perhaps could have been negated by the use of a Panhard rod or some form of Watts linkage to maintain central location. But despite the disadvantages, the suspension bushing did contribute greatly to the Scorpion's ride refinement. So did the two piece propeller shaft with a central constant velocity joint. It was similar to that used on the TF Cortina, and before that, in the Commodore. It prevented the transmission of rear axle noise and vibration, something which certainly detracted from the GH Scorpion. It was also effective in smoothing out the drive from gearbox to differential. Brakes all round were disc as before, while the same type of aluminium fourteen inch wheel was featured.

On the Road

Once you had a little time behind the wheel there was no doubting that the GJ had an improved level of ride. Suspension movement was well damped and even the roughest of roads would fail to bottom the shock absorbers. As with any car from the era, the rear end could be caught out on the odd sharper bump, but unlike the GH there was little tendency for it to hop sideways. Handling at high speed was also precise. There was basic understeer and this could become accentuated in tight corners taken a little too fast which was, arguably, just as it should have been. Because of the steering geometry revisions, the steering felt a bit more responsive, and never seemed to become particularly heavy even at parking speeds. Turning into a corner was a positive operation with acceptable feel coming back through the wheel. Reasonably balanced, only minor correction was required when cornering close to the limit. Roll oversteer could be experienced under high lateral pressures, but it was very gentle and gave plenty of warning of its approach. No rear sway bar was fitted as standard.

As with the GH, there was no way that the GJ Scorpion could have been considered as even to be approaching the sports car class. Rather, it was a boulevard cruiser, based on attractive style and a high level of equipment. Better than that, however, it represented a marked improvement over the older model. Noise and vibration attenuation was particularly successful in relation to the engine and transmission. More so than on the two litre Astron unit, the 2.6 always used to be a fairly harsh sounding operator, even though it was as smooth as the marketing men claimed it to be. But on the GJ, thanks to an excellent sound deadening package added to the chassis improvements, it could be heard only when revs were approaching the red line.

Further demonstrating just how far the engineers went with the redesign, even the spare tyre was indented into the fuel tank, and to make the available space more useable the wrap-around rear lamp housings were re-designed to minimise their intrusion into the boot space. Both the front and rear suspension were redesigned to improve handling and road-holding, the changes including a reduced king-pin offset at the front and a redesigned four trailing-link and coil rear suspension. The 2.6-litre engine with its unique counter-revolving balance shafts was the largest four-cylinder motor then available on the Australian market.

More Torque

Changes to carburetion and ignition increased power marginally with a slight drop off in torque. The overall result was a smooth range of operation from low down lugging all the way to maximum engine speed. Everyone who wrote about the GJ was convinced the new model was more tractable than the old – which probably accounted for the marginally improved acceleration figures. Zero to 100 km/h would come up in 10.5 seconds, and the standing start 400 metres in 17.8 seconds. It was the gutsy torque that was the key to the 2.6 Astron's astounding fuel economy though. It allowed greater use of fifth gear under a wide range of conditions, and around town it was possible to achieve around 10.5 litres/100 kms. On the open highway it would dip to under 9.0 litres/100 kms. For the record, Mitsubishi’s AS 2077 claim was 7.2 litres/100 kms – but we have mentioned in many other articles here on Unique Cars and Parts just how inaccurate that figure was.

Behind the Wheel

The main advantage of the extra torque was in towing situations – something that the 2.6 litre engine was well suited to – almost approaching 6 cylinder territory. For long distance travel the GJ Scorpion was extremely good. Very low interior noise levels and effortless performance produced fatigue free driving over extended periods. But it was easy to exceed the speed limit too. Such was the quality of the sound deadening, and the effortless nature of the engine, that it was easy to find the speedo creeping into the speeding fine territory.

Behind the wheel you soon realised the Scorpion offered good, but not breathtaking, performance, affording a top speed of around 175 km/h and acceleration to 100 km/h taking 13.7 seconds. If driven (very) carefully it could return consumption figures around 10 litres/100 km. Most important to the 1981 revision was the all-new variable rate power steering that employed a principle pioneered by the European car manufacturers. At parking speeds full assistance was given, but as speed increased the assistance decreased thus retaining precise steering with good road feel. The sophisticated twin-circuit brake system employed a pressure-sensitive load-proportioning valve to ensure that the four-wheel discs worked to maximum effectiveness.

In all, the Scorpion was a good car, but not great car. Interest soon declined in the model, and has never been rekindled by enthusiasts to the extent that the car could be considered either classic or collectable, which is a shame, the Scorpion deserved better. Being a fully imported vehicle, the Scorpion was subject both to import quota licence restrictions, and to fluctuations in currency exchange rates.