Road test - Porsche 944 Turbo- Stuttgard Slingshot

That "turbo" tag is one which has been much misused applied to many an ordinary car in an attempt to convey glamour performance and power, it has frequently denoted instead an unbalanced amalgam of high power and low refinement, and over-advertised with loud badges to boot. But there are some companies which strive towards a programme of model development which results in their cars progressing steadily on all fronts.

Such a company is Porsche. While there have arguably not been any "failures" from the company in recent years, such criticisms as occur outside or inside the firm are usually answered in a succeeding version — visual differences within each range may be minimal, but the sum of the changes is always apparent on the road. This constant progress percolates steadily down through the range with the added bonus that the existing customer is constantly tempted by the next model. Porsche is very proud of its customer loyalty.

Porsche's range of cars is an extravagant one — three entirely distinct lines, all offering rapid 2+2 motoring. No fast four-seaters to chivvy BMW, no mid-engined two-seaters to alarm the Italian exotics, merely beautiful engineering applied to unconventional layouts, and thorough development to rival that of any car manufacturer in the world.

It is that development which has seen the 924 evolve from the baby the starter model of no particular pedigree, through the phenomenally successful 944, the touchstone of executive success, into the 944 Turbo — an easily-guided missile which now threatens the pedestal on which sits its own relative, the 911 Carrera For the two cars are now comparable both on price and performance — both are claimed to make 152 mph, both cost around £27,500, and while the bigger, engined 911 can shave a couple of tenths off the standing-start times, the Turbo's sensational mid-gear acceleration quickly redresses the balance.

So why should the wealthy driver be tempted by the unremarkable lines of the 940-series car? He might need those rear seats, for instance; although they are barely tall enough to squeeze adults into, they do make better emergency accommodation than those of the rear-engined car, and folded down also provide reasonably practical, if shallow, boot space. Perhaps, bank balance depleted by the expensive Porsche option list, he needs to watch his fuel bills; four cylinders consume the stuff at a very restrained 23-25 mpg, while six are some 3-5 mpg thirstier. If he lives in a country with emission controls, he can content himself knowing that the 944 Turbo is the first car to offer identical performance in all markets — where a catalytic converter is fitted, the boost is slightly higher and the Bosch Motronic intention system is reprogrammed to suit. Should he be interested in technical innovation, the Turbo boasts a water-cooled turbocharger, a charge intercooler, gearbox oil cooler, the advanced TOP cylinder head, and the Bosch Motronic engine management system. In addition to all this, the inherent balance of the transaxle chassis removes that faint but perhaps distracting doubt about whether the driver will be quick enough to catch the weighty tail of the 911 if he discovers a patch of diesel on a roundabout.

Based on the all-alloy 944 unit with its twin contra-rotating balance shafts, the 2.5-litre four-cylinder single-cam engine with its TOP (Thermodynamically Optimised Porsche) combustion chamber shape runs at a healthy 8.0:1 compression ratio. A knock sensor retards the ignition if low-octane fuel should cause pre-detonation, even releasing the wastegate completely if necessary, while conversely the engine management system will close the gate under maximum acceleration allowing overboost to push the torque up by 10% for a short period. Forged pistons, high-temperature valve components, ceramic inserts in the exhaust ports and the intake air cooler help the Bosch electronics to optimise combustion. Whereas many turbo units place the turbine near the exhaust ports to reduce response time. Porsche have mounted theirs on the opposite side to reduce the heat gain, without inducing turbo-lag, while two water-cooling circuits dispel the waste heat from the turbine. One is part of the main system and operates while the car is running, and the other cuts in when the ignition is switched off to pump coolant around the turbine's bearings, preventing the lubricant from being burnt away in the first fiery seconds when the oil stops circulating.

Weissach designers even work on the underbonnet appearance, on top of the 30 degree canted block sits an unusually shaped intake / injection manifold which dominates the packed engine bay. Cam drive is by toothed belt, while that for other ancillaries is ribbed inside and out so as to drive the balance shafts in opposite directions.

With a torque peak of 243 lb ft at 3,500 rpm and a full-bellied power curve which soars to 220 bhp at 5,800 rpm while punching out an impressive 145 bhp even at 3.000, the urge of this engine is sensational. Sadly, sensations were all I could depend on to gauge the accuracy of Porsche's performance figures, as heavy snow on the Bruntingthorpe test track prevented its use. However. experience with previous test cars suggests that the maker's 0-62 mph time of 6.3 sec is probably conservative.

The Turbo shares the transaxle layout of the 924S and 944, but the five-speed gearbox between the rear wheels has been strengthened and its ratios raised. Clutch diameter has also been increased. Suspension layout remains the same but now uses the alloy front wishbones and rear semi-trailing arms which replace the steel ones throughout the four-cylinder range. A front anti-roll bar has been added, together with stiffer shock absorbers, and four-pot calipers on four vented discs look after stopping the car. Only one tyre combination is offered —205/55 VR16 on the front, 225/50 VR16 behind — but the 928-style alloy wheels can he replaced at extra cost by forged black 911-pattern ones of the same 7J and 8J widths. Sport seats, shock absorbers, and a limited slip differential are also available.

Power-assisted steering is standard on the 944T, and no-one could quibble about that. The system is absolutely superb, preserving an ideal weight in the driver's hands whether he is reversing into a parking space one-handed or balancing the car through the fastest of bends, and all the time there is as much feel as anyone could hope for. Assistance varies with both load and speed, and the leather wheel is lust the right size. It is also better placed than before, a little higher, and the new Recaro seats are about an inch lower so that the wheel is no longer in the driver's lap. A new dash layout (which will become standard on the 944 Lux too) has easily read instruments, though sunlight causes severe reflections on the minor dials, and the switches and stalks borrowed from the Golf are replaced by much smarter 911 items, giving a better quality feel. Most of these are easily reached, though the rear wiper switch is obscured by the leather gear-lever, but that handbrake is still exceedingly badly positioned, too low and too far away. Other fitments include air-conditioning operated by a neat and logical panel above the gear-knob, and an electrically tilting steel sunroof, which can be removed and stowed in a bag in the boot. A sophisticated Panasonic radio ./ cassette with four speakers and an aerial concealed in the windscreen, and a central cassette holder-cum-armrest round out the interior fittings.

External differences from the normally-aspirated 944 are restrained: the deeper sill-panels are almost unnoticeable, and the under-bumper rear wing is subtly integrated into the body. But the svelte new nose suddenly out-dates all other 944s. Shaped in deformable polyester and glass-fibre, it incorporates auxiliary lamps and brake cooling ducts in one smooth panel, a lovely piece of design which markedly improves the car's looks. As in all other areas, Porsche has been very thorough over the aerodynamic details, engine bay floor panels smooth the passage of air under the car to the new rear apron, which the company says helps to cool transmission, exhaust, and petrol tank. External vents for the cabin are avoided by extracting used air via the door shutline.

All the changes which mark out the turbo are, inevitably, subservient to its new power-plant, and what a magnificent engine it is. Start it up (it fires instantly every time) and a new gruff exhaust note is apparent, under load this turns into a mild snarl which is most unlike a turbo.

Clutch take-up is progressive, not at all heavy and the gearchange is quick, if not of the smoothest, so that the flow of power is almost constant through the new longer ratios. Most delightful of all, is the part-throttle performance: the flaw in many turbo systems is the difficulty of smoothly controlling the acceleration at less than full throttle, but the 944T surges ahead with even middling pedal pressure. What delay there is in spinning up the turbine below 3,000 rpm is no greater than letting any normally-aspirated engine get on cam, and it is only the dramatic build up of acceleration once the throttles are wide open winch underlines that this is indeed a turbo.

On dry roads the traction of the rear tyres is almost unbreakable and where mud, water, or a severe bump momentarily separate road from rubber, any slide which results is brief and predictable almost self correcting. Instantly obedient to small steering movements, the chassis displays the mildest understeer as the car settles into a corner then balances itself effortlessly as the throttle opens. It feels quite neutral as the lateral forces build up and the amount of grip available is terrific: push it harder and harder and the tail begins to hint at oversteer, but this happens at such high speeds that it would be almost impossible to find a bend on the road long enough to push it that far. Lifting off makes the nose drop and tuck in but not enough to upset the rear, making this a safe method of fine adjustment to back up that delicate steering.

Neither is the poise of the car upset by Government cut-backs, made manifest in potholes; the firm damping insulates the shell from all but the worst shocks, and despite their width, the tyres ignore most interruptions. The result is a chassis which feels utterly confident under all conditions, and which manages to feel taut cornering at 100 mph without giving the occupants an uncomfortable ride in town. It is robust, rather than silky smooth, but it is what a sportscar should feel like.

Even in fifth gear the car is very quick; play with the well-spaced pedals to slot into third and it bolts forward, gulping the longest straights without pausing for breath. There is an electronic fuel cut-out at 6,500 rpm, should the driver be too busy looking at the road to notice the tach needle, but with acquaintance one learns to select one gear higher than normal and let the turbo do the work. With 2nd, 3rd, and 4th gear speeds of 66, 97, and 132 mph, there is plenty of headroom. The brakes feel very strong, well able to control the car.

Cabin comfort is good, wind and mechanical noise being well suppressed, though, like in any wide-tyred sportscar, cats eyes and road-joints invoke loud thumps. Air temperature and flow are controlled electronically and are quickly altered and there are four large fascia vents of which the outer ones also look after side window demisting; there is, however, no facility for fresh air while the heater is on. Seat height and backrest adjustment are electric, and the seats give good side support, very valuable in a car which can corner as fast as this one. Leather seat facings are standard, though the test car had full leather seats (which incidentally make it much easier to slide in wearing a kilt!) and electric windows, central locking, remotely adjustable heated door mirrors, and heated windscreen washer nozzles are all part of the package. One safety feature easily missed is that the wipers have been reversed for the UK market.

Calling the Porsche 944 Turbo a luxury car would be misleading: that term usually implies that comfort is the primary factor, even above performance. What then does one make of a car which has phenomenal abilities, and allows its driver to exploit them surrounded by all the material symbols of luxury? True, it is not silent in the way of a Jaguar XJS, and aspects of its capabilities are naturally short of the handful of true supercars costing considerably more but it is beautifully assembled so that the doors click dosed and every control feels firm. It is also expensive. For those who value aesthetics. £28,000 is a huge sum for a car which recognisably derives from the bulbous 924, when the same would purchase the venerable 911's lovely curves.

It is said that car enthusiasts aspire either to a Porsche or a Ferrari; I confess to a strong Mediterranean leaning amongst the normal run of test cars, but a week with the 944 Turbo has suddenly put me in danger from that mythical creature the two-horned dilemma. — G.C.