Dit is de derde generatie van de Porsche Turbo. Hij werd getint naar de reeds gekende Porsche 959 en had ook een beetje een Porsche 928 look. Hij heeft een 3.6-liter motor aan boord, met een vermogen van 400 pk, 18" wielen. Hij gaat in 4.4" van 0-100 km/u en haalt een topsnelheid van 180mph.

De achtervleugel is platter, opnieuw kreeg deze Turbo een grotere wielbasis om grotere banden te kunnen gebruiken.

English information about the Porsche 993 Turbo

When the 965 turbo 2 makes its entrance in 1991, a lot of people have been disapointed by the fact that the car retakes the old 3.3 engine ( born in 1978 ! ). In 1993, when the turbo 3.6 appeared, it was quite the same thing : despite the choose of the new 3.6 flat 6 (M64), the car was showing same appearance and the 5-speed gearbox. So, in 1995, a totally new turbocharged model came into sight : the 993 turbo.

But what's a Porsche 993 Turbo?
The Porsche 993 turbo is such an amazing car, beautiful, performant and ... fonctionnal. The car is capable of the worst things on the road but in spite of it, the 993 turbo could be driven everyday very quietly without a problem. The huge preformances obtained only match with the luxury & comfort reached and the driving facility. The 993 turbo goes as you want : calm and civilizated or fast and wild. Small evolutions can make the difference between the 993 Carrera and turbocharged models. First, the 993 Turbo has got new 18" rims, a new fixed rear spoiler, wider wings on front and rear and steps on sides. The front spoiler have also been redesigned, for better aerodynamic and cooling performances. A main central air intake goes to the oil radiator and the little ones on sides allow discs to be freshen up. Don't forget the huge red brake callipers, with Porsche tiped in white on them... Absolute class in fact!

How can I drive in total security, how can I exterminate the first BMW M3 3.2 without renoucing at an entire comfort and luxury ? Simply go buying a 993 Turbo. The body shell has been reinforced, two frontal airbags protect both driver and passenger. The cockipt is full of leather and seats has got a multitude of adjustment. Seats are hyper-comfortable and provide a very good keeping capability. If you are mad about circuits, sport seats are proposed as a free option and of course, they are always in leather too but colors are more... shimmering. The handwheel is something extraordinary to touch, very sweet and at an ideal height. The apparent seewing are very impressive. It is just Porsche quality, nothing else.

What's new in the 993 Turbo?

The engine
If the 3.600 cubic capacity is the same than on the previous model, the management system and the two turbos are totally new. Indeed, in spite of the fact that Porsche have been a pioneer in turbocharging a car, they used to utilize one single turbine till 1995. If the engine was from a relatively simple architecture, the single turbine induced a real kick when it came into force, around 3,000-3,500 rpm, according to the different models. If it was real pleasure on a highway, it was quite dangerous or exciting in little mountain roads. The 993 Turbo isn't the first production car to have 2 turbos : the extraordinary 959 did it in 1987 but it was a sequential installation and the discounted effect (minimizing response time) was not achieved, great power only came when the second turbo came into action around 4,500 rpm (in fact, performances were the same of the 930 underneath this power rating : there was again the famous time of response).

The installation of the 993 turbo is simpliest and more efficientely. Each turbo (KKK-K16) is directly feeded by a 3-cylinders bank. From each turbo, which are the closest possible to the cylinder head that feed them, the air compressed flow goes through an intercooler, at the exit of which the two flows meet at the top of the butterfly intake and of the collector that feed the two cylinder banks. The turbocharging pressure is limited at 0.8 bar by the restriction valves, incorporated to each turbo and electronically adjusted by the engine management system, which also integrate an anticlanking regulation. This electronic management allows to put up the compression ratio from 7.5:1 to 8.0:1. Intercoolers are directly placed under the air intake grid of the engine cover and the circulation of the cooling air is activated by the engine cooling turbine which keep a depression in the engine compartment. All these modifications raised up power from 360 hp to 408 hp @ 5,750 rpm and torque from 53 mkg to 55 mkg @ 4,500 rpm. Of course, the flat-6 is not at the maximum of its capability (look GT2 for example) but Porsche would like 300 kW, they obtained 300 kW!

All these huge measures required modifications compared to the atmospheric M64 engine. The M64 turbo retakes the rocker arms with hydraulic thumb pieces of the original M64. So, cylinders are forged instead of being casted in aluminium and the cooling small wings are manufactured to obtain a better circulation of the cooling air. In a same way, the speed of the cooling ventilator increased by 15%.

With a view of the high pressures reached in the cylinder heads, the thickness of them have been enlarged like jets which ensure the piston seat cooling by oil throwings. The push rods have also been reinforced. At the contrary of the original M64, the M64 Turbo only features a single spark ignition per cylinder because there wasn't enough place anymore for the second alternator ! In compensation, like the M64, the 993 Turbo engine features a bi-mass handwheel which put an end at the transmission sounds at lower rating.

As a result of this installation based on 2 low-inertia turbos combined to a modern engineelectronic management system, time response has been reduced to a very insignifiant quantity, like on a Ferrari 5 liters flat -12 engine with 48 valves for example and the coming of the engine thrust is very progressive, more exploitable than on any previous turbo model. At the sea level, turbos rotate at 167,000 rpm and more as altitud increase. If you decide to go very high with a 993 Turbo, just know that the maximum torque is preserved till 3000 meters.

The All Wheel Drive System It is the first time that Porsche propose a permanent integral transmission on a turbocharged model excpetion made of the 959. This system is derivated from the 993 Carrera 4 one. The transmission to the front wheels is ensured by a viscous clutch which brings only 5% or 15% of the torque on gripping ground (in regard of the accelerations), that's why the 993 Turbo keeps a traction behaviour and by this way, it is not advised to accelerate very hard at the end of a curve under trajectory problems. The integral transmission is simply a compromise and despite the fact that the traction behaviour is conserved, the 993 Turbo allows real unbelievable speeds on wet coating. This system only weights 50 kg. Motricity is also improved by an mechanical limited-slip differential, blocking at 25% under load and at 40% under deceleration (which reduce the tendance to oversteer when releasing the accelerator in a curve) and by the automatic differential brake (ABD) that electronically steps in to slow down a wheel which slips more than the others under 70 kph.

It is also interesting to note that if the rear wheels slips too much or began to do it, the excedent of torque is set up to the front wheels. As a result, the acceleration of a 993 Turbo is easy to dread and quite despite the power brought to the road.

New Brakes
The 993 Turbo is a pure product by Porsche so, the brakes are far away to be blowed, even on a circuit. All is made, from the cooling to the callipers and by the way to the rims, for the best result in power, endurance and utilization. The diameter of the rear discs have raised from 299 mm to 322 mm. As a result, they are as big as the front ones but the braking power is more replied on the front whells than on the rear ones. Brakes are commanded by a high pressure circuit and the four channels ABS 5 system gives up short braking distances even on irregular roads and with not any chance of blocking. Of course, the discs are air cooled by the big air intakes in the front spoiler, laterally & radially ventilated and perfored but the design of the rims provides a better heat rejection than on previous models.

New 18" Rims
New aluminium alloying rims have been developped for the 993 Turbo. They are particulary interesting by the fact that they are featuring hollow-spokes and the central point of the wheel is united to the rim by friction welding which ensure a lot of lightness, solidity and precision. To compare with a rim of the same size (8"x18" & 10"x18"), respectively 2.6 kg and 2.9 kg are won on front and rear traditionnal rim for a total of 11 kg.

Other Features
The 6 speed sgearbox is from the 993 one and the 6th gear is a true one, not for lowering consumption on highway, like on the 959 or the Corvette ZR1. Despite the huge torque, the different gears are very easy to engage, Porsche reviewed the synchromesh of the 1st and 2nd gear with double-cone which reduce effort during gear-shifting despite the big power of the engine combined to a strong gear ratio. The clutch pedal is very easy to use for a car of this power level, unlike a Diablo for example. The same hydraulic system used for the brakes assist the clutch operation by lowered force needed by some 40% than on previous Turbo. The course of the clutch pedal is also shorter. The effect is immediately perceptible in a town where traffic and traffic lights are very cumbersome for supercars ingeneral. The only drawback of the 993 Turbo in city circulation is is large turnig radius, due to her wide tyres. Other features came from the lighting, always disappointing on every previous Porsche. The 993 Turbo shows new Litronic headlights which use gas discharge lamps, feeded under 85V by a little transformer. Tests make appearance of twice the power of a traditionnal hallogen lamps.

The Roadtest
Power is nothing without control... That could be the slogan of the 993 turbo. From the first hundred meters, you're discovering a very flexible car, thanks to the light clutch pedal, very sensitive and soft which is very useful in city traffic. The torque available is from low rpms is comfortable, just enough to have a quiet balade at 30 mph... But when you get the better of the accelerator, guess you aren't cardiac cos it is really devastating for brain & heart ! In spite of the AWD system, the large tyres and the body height, you should let two big black marks on the asphalt... Here it is important to note that the first gear is very efficient to quickly get out from the stop. Porsche has made a very strong gear-ratio (3.82:1) for two reasons : to increase accelerations and also to light the work of the clutch pedal. Indeed, because the gear ratio is short, you'll have to use the clutch pedal during a short time, which is better. No need to let slip the clutch to have a slow start or to park the car. The 993 Turbo is marvel of stability and the power available, exploited by an excellent gearbox is absolutely incredible. The accelerations are very powerful and on an highway, you just can't imagine the rapidity of the car among the traffic. Just see and withdraw ! That's as easy as passing bikes with a motorbike ! The engineers have made a wonderful engine, very far away from the first 1975 930s. No dead times, the engine propels you in an uninterrupted breath til the red line. Flexibility is another key word for this turbocharged engine. No kick in the back around 3,500 rpm, on the contrary of single turbocharged Porsche engines. For now, the 993 turbo come as the best handling 911 ever built.

You'll see in the table that the 993 Turbo has got a really good place and even if she's beaten on a staight line by a Diablo, the Lamborghini would have bad time trying to leave the Porsche behind and moreover on a fullcornerings road. It is also true for the F550 and the Porsche 993 Turbo, but in the other side ! Ferrari placed the level very high with the Maranello and the next Turbo is for 1999...and the GT1 doesn't run in the same category...

Porsche facing Pollution
The philosophy of Porsche is very good because they think that a powerful car is unusable if it can be ratified by a country. That's true and since there are Porsches in the USA, they are made to reply at the pollution rules established. The 993 Turbo is a great example with an entire system devoted to control nocuous exhaust fumes. The 993 Turbo uses a Bosch Motronic M 5.2 system that allows to control the air flow breathed by a bypass valve integrated in the turbocharger. The mass air flow measured by a hot film sensor is compared with the required value stored in the management system.

The Bosh Motronic system also reckons engine speed, throttle position, ambient pressure and temperature and also knock. Then, after passing in the turbochargers, the exhaust gas flows through two independent metal-carrier catalytic converters. Four oxygen sensors ( at top and bottom of each catalytic converter ) ensure the best monitoring and control the exhaust gas composition. As a result, the 993 Turbo is a very clean car, even on great accelerations or at high speeds. Polluant particles emissions are very low, more than values fixed by the californian anti-pollution laws for example, nevertheless the worst on Earth. The Bosch Motronic system also features a embarked diagnosis system from the 2nd generation ( OBD II ) which is in fact the "responsible of polluting department" in the 993 Turbo. As a matter of fact, it controls the oxygen sensors and the catalytic converters exhaust system, the secondary air injection system and the fuel system. The OBD II is charged, beyond work achieved by OBD I, to signal any disworking of : the two catalyzor converters, the active charcoal system used to ventilate fuel tank, the electric secondary air pump, the fuel mangement system, the Lambda sensors and to detect possible ignition problems.

Porsche facing the conccurence
Well, a little table is clearer than a long page... As you'll see, the Porsche 993 turbo has got very uniform performances and its price and luxury make of her one of the best choice possible.

Nota
Values of maximum power & empty weight are from the manufacturer. Performances have been obtained on test. For manufacturer values, check Supercars.net. Some differences might occur : each manufacturer want to produce the best car ! At the interior of the table, the best values are in yellow. The performances of the Venturi 400 GT are tiped in Italian style because they've not been authentified. The Venturi didn't "win" the 0 to 100 kph test for reasons quoted before. Those 8 supercars have been choosen by their weight/power ratio and not in regard of their power nor price.