Asked what angle shows a Turbo off best, one can only reply: "there aren't any angles but all voluptuous curves." A trend the new Turbo continues and fortifies.

The designation "reasonable supercar" is either an oxymoron or a Porsche 911 Turbo 3.6. Probably both. It's certainly a fair title for the king of the most highly developed lineup in sportscar history. The flat-six, air-cooled 911 is just turning thirty and proud of it. Originally innovative, this 911 range, topped by the Turbo version for two-thirds of its long life, has given new meaning to "thoroughgoing development."

Since its 1963 debut Porsche has nearly doubled the displacement and nearly tripled the output of its unusual engine, without losing the car's basic shape or its unique aura. True: nobody else has followed their lead so it's hard to call the 911 a pathfinder, as Porsche does. Maybe no other car builder had the nerve to build a 911 copy. At least Porsche never felt any compunction about that.

It's hard to credit today but a large chorus of self-appointed Zuffenhausen pundits decried that first 911 (901) on the grounds no true Porsche could have a six cylinders. They, or their off spring, are just as vocal today in claiming nothing BUT a 911 could be the one true Porsche.

Neither faction gets it completely right but the firm itself has never admitted limits to the 911. Their latest and largest Turbo underlines that point.

This engine variant is based on their unblown 3.6, but there is already a limited-edition 3.8RS so the limits haven't been overstepped quite yet. That said, growth potential shrinks with each enlargement so this might well remain the largest turbocharged 911 of all - Untila new flat six appears towards the end of this decade, that is.

The Turbo was already declared dead under Ulrich Bez, when they believed noise and emissions laws could never be met without major sacrifices of power and torque. Their 3.3 Turbo would crown the line. Then the metal-core catalytic converter came along, with much back-pressure and higher heat rating. The Turbo project team was given just one year to do a 3.6. Twenty men from all sections of engine design leapt at it; and made the deadline.

All that rush is one reason this new Turbo has two-valve heads. They know them best. More important, racing experience, which still plays a happily large role at Porsche, indicated that four-valve turbo heads must be water-cooled. When/if they build a new basic six with four-valve heads, the "answer official" will be different. The trick here was finding a massive torque increase.

An extra 300cc helped, compression was raised from 7.0:1 to 7.5:1 and the injection chip reprogrammed. This, plus that new cat technology, produced not only a quarter more power (360 hp at 5500 rpm) but a massive boost to 383.5 lb-ft of torque, peaking at 4200 rpm. More important to improved "drivability," they have as much torque as the old engine's peak (332 lb-ft) at the way from 2400 to 5500 rpm - quite a range indeed.

Changes required to make a turbocharged 3.6 are largely detailing. They include a new bore for the oil filter, different pistons, head and camshaft blanks, Turbo S cam timing, necessary changes to cam covers and small alterations to sheet-metal shields. The engine map, bypass valve spring, rev cutout and air-volume sensor are recalibrated. This drive unit is then mounted on hydro bushings. These and a dual-mass flywheel reduce noise considerably.

In a passing bow to current concerns, Porsche notes that official consumption figures (17.7 mpg on the three-way Euro-test) remain the same, but real-world thrist should be lower.

That assumes you'll drive the 3.6 Turbo at the same pace as its predecessor, a dubious presumption at best. Why pay a very healthy DM 204,000 for a car capable of 174 mph and 0-60 in less than 4.8 seconds if you plan to poke along at a mere 68 or so? If Porsche intended Turbo owners to drive so sedately, would they have moved this new car a whole stiffness grade towards sporting?

The project engineer calls it "more active" on the road. Translation: it was lowered by 0.8 inches, springs stiffened 12% and shock absorbers calibrated to be strongly degressive. It seems so many Turbo buyers rushed off to some tuner for a sportier chassis, the firm decided to preempt them. Three-piece , 18" wheels from the limited-edition Turbo S, 8/10" wide, carry 225/40 and 265/35 rubber. They don't help the cushioning much but 17" wheels would fit if you value the family fillings.

Being Porsche, they naturally fitted the best brakes in the parts bin. Never mind that 3.3 Turbo stopper were already class leaders. These vented and cross-bored discs (still 12.7 inches in diameter) have more friction area by a good fifth. Red paint on the four-piston, fixed, aluminum saddles identifies them. In figures, Porsche claims 62-0 stops in 116.8 ft = 1.11 g and 125-0 in 430 ft = 1.20 g. The 3.3 returned 1.01 and 1.10 g on similar fade tests. Pedal pressure and travel have been reduced as well. In fact, they redesigned the whole pedal unit, largely to try and keep clutch pressures within human bounds despite a stronger, dual-spring layout demanded by the new torque peak.

Drive shafts and a standar, laminate, limited-slip differential are stronger too. The car produces up to 20% lockup under load, up to 100% on overrun. After all that, Porsche found it could carry the five-speed, manual gearbox of their 3.3 Turbo over without changes.

Officially, new wheels and fresh scripts for the tail and backs of the fold-down rear seats are the only 3.6 Turbo giveaways. The familiar whaletail spoiler and bulging fenders continue, although Weissach aerodynamicists did manage to squeeze a tiny bit from the rather average Cd value. It's 0.35 now (from 0.36), showing the car's age. On the other hand, lift is a commendable zero.

Inside, any owner of a two-decade-old original Turbo would find all chief dials and switches in the same places. The new car has such standard features as on-board computer with digital boost readout, two air bags, an eight-speaker radio or CD to choice, alarm, headlight cleaning, air conditioning and leather. With their nose compartment cut in half by the hump necessary to hide 4WD in a Carrera 4 (inexplicable carryover), luggage capacity is actually less than a 1973 Turbo. They don't like to hear the old tale of Ferry insiting a 911 should take golf clubs, to set it apart from the 356. Opt for the 24 gallon tank and you'd be hard-put to carry a set of darts.

And none of this matters a damn once you find a rallye-stage sort of road behind the Riviera.

Getting there is no strain either. Firmer ride is admittedly biased towards maximum stability on high-speed German autobahns but the car is still comfortable enough for fairly poor city streets at low speeds. This 3.6 Turbo easily continues the tradition of effortless action around town. Sure, the clutch is still heavy and the gearbox wants a firm hand, but both work like Porsche parts and anyway, the car trickles along at low revs just fine.

At highway speeds it's uncannily quiet for an air-cooled 911, even a Turbo. What's more, you are barely turning 2000 rpm in fifth at 60 mph. On the other hand, first and second gears are relatively short so that it only takes one showy departure when the light goes green to start bouncing off the rev limits, a very raw-edged deterrent indeed.

On rough roads or gravel, where you can push the 110 mark, the ride becomes TOO firm and the car wants to dart from side to side. Back to the olden days at Porsche. Let the wheel jitter in your hands and restrict corrections to major direction changes. Turn in is very sharp, steering just heavy enough to feel safe at speed.

There is some sensation of boost at 3000 but the real surge doesn't come until the needle says 4000 rpm, leaving about 2600 revs to play with for track-type games. You shift a lot and can't snap them in with a box built for 380-plus lb-ft. Half a beat per shift and no hestitation is the way. Power comes on smoothly, even under full throttle but there's a brutal jerk if you lift off suddenly. Handling limits are so high on road-roller tires it takes a hairpin to feel the tail ease outwards in normal use. Testing the outer edge in fast sweepers is better left to a session on some closed circuit. Even then, brake fade will not be a word in the 3.6 Turbo vocabulary.

Porsche may well be riding a cresting wave here. From all reports the ultra-power, exotics race may be about over. XJ220 Jags are going for half the sticker sum, Yamaha recently put its OX-99 on hold, Bugatti reputedly has trouble finding even old fans for its reborn EB110, while the V16 Cizetta is moribund and even McLaren's F1 orders lag.

It's hard to call a DM 204,000 car capable of nearly 175 mph rational but this does look like being about as much ostentatious power and prestige as most people want for the '90s. Besides, you can see every corner of a 911 Turbo 3.6 and tuck it in where even big sedans fear to tread. Nobody turns the Diablos of this world over to valet parkers.

Maybe "reasonable supercar" isn't such a wild idea after all.