Resurrection of the turbo - Porsche 911 Turbo (type 964 ver 1) [review]

THE 1990 PORSCHE 911 TURBO (type 964) [review]


It looks pretty familiar, afterall the 911's shape has hardly changed much over the 25 years of its existence. The previous 911 Turbo had been out of production for about 17 months before it had a replacement. A curious state of affairs since most logically one should have a replacement model before stopping production of the "old" one.

Well at Porsche, things are run differently. Besides having their hands full at the moment (like assembling the new MB 500E), several new "emission standards" were changed during the Turbo's gestation, effecting their planning. So, with these changes in mind the Porsche engineers set a goal for themselves. A single model that can satisfy ALL the emission standards in the world, instead of the usual collage of models for the major markets of North America, Europe and the Pacific Basin countries. An interesting concept and if they are successful, this may well become a new "world standard". For now, we'll treat this as a novelty and sit back and watch, remember you read it here first.

Porsche had a 170 km route plotted out for our extended drive on the official day. However, on the day before, Mr. Klaus Reichert of Porsche's Press Relations Department kindly offered us the chance to have the 911 Turbo a day ahead of(and in addition to) the schedule. Needless to say the offer was most gladly accepted, especially since the week before we arrived the entire test fleet was stolen! An embarrassed Porsche summed up all available pre-production test vehicles from Weissach to complete this drive event. (update: on the very next morning one stolen Turbo was recovered from a ditch but the rest were missing for a year despite French police efforts. Eventually the entire fleet was found in an abandoned barn in the countryside a year later. The insurance company having paid for the loss were now the owners of the stolen cars. There is no indication if these pre-production cars were ever sold at the auctions)

The keys to the bright red 911 Turbo were picked out from a bunch of twenty keys, all belonging to a most stunning collection of 911 Turbos parked just outside the Hotel. We were off. The key slot proved a little hard to find, placed to the left of the steering column (LHD car), slightly obscured from direct view by the oversized steering boss which houses a mandatory airbag. This high-tech gadget, hidden from view just above the now smaller glove compartment also provides protection for the passenger. Should you hit an obstacle at speeds higher that 25 kmh, the airbags will be deployed. So effective are the air bags, the occupants in the front seats hardly remember the airbags saving them from a head thumping on the steering wheel or front windscreen. All they see is the deflated bag on their laps and bits of glass all over.

Unfortunately, repairing the deployed airbags is a $5000 job and perhaps more with all that fine leather it rips through. The instrument panel and fascia has hardly been changed except for the inclusion of a myriad of warning lights within the oil level/pressure gauge on the left of the tachometer and a trip computer that is only useful to the driver at speeds close to standstill. Interesting information is available and undoubtedly accurate but with the 911 Turbo at full wick, how much boost pressure or what's the fuel consumption over the last 0.95 km is hardly a top priority compared to the job of keeping this, the most expensive 911 on the road. It would make more sense if they included a separate analogue boost gauge to make reading at a glance easier. For those of you who are interested, the housing of the instrument binnacle and much of the dash skeleton is actually structurally welded to the rest of the front chassis, not bolted on afterwards.

Despite the ambient temperature being pretty low, the engine fired up without a fuss after the customary churning over coming to a fast idle accompanied by that familiar mechanical clatter so characteristic of an air-cooled engine. These pristine examples were obviously given a thorough going over before being delivered to the journalists. In fact each car is checked by a crew of dedicated Porsche mechanics at their makeshift service centre in the Hotel's courtyard everytime a 911 is returned. (which was where the entire fleet was stolen from in the first place in the middle of the night)

The engine is surprisingly quiet and refined, only a subdued thrumming of the rear mounted motor could be heard. That was at idle, revving it up produced the kind of noises expected of such a legendary car but this turbo-motor seemed to have less mechanical noise than the 3.6 litre engine found in the Carrera 2. The large exhaust pipes at its rear were noted more for their voluminous discharge of "clean" exhaust gasses than noise. Only during the operation of the full-boost does the left branch of the exhaust discharge gasses, and that is also through a separate catalytic converter from the main one, ensuring the exhaust gasses allowed to bypass the turbo at maximum boost are sanitized as well.

According to Paul Hensler, Chief engineer in charge of engine development, the turbo engine is different from that in the Carrera 2 and 4 as it is a development of the M30 engine from the last Turbo.  Although the bore centres are similar, the bolt pattern and internal channels are too different to allow component swapping between the M64 3.6 and M30 3.3-litre turbo engine. However he did not specifically rule out a M64 3.6-litre turbo engine in future which seems to be the most logical evolutionary step for development.

First gear of the G50 gearbox was not located racing-style, a dog-leg below reverse but in the normal position atop the left arm of the "H" pattern. Good! But finding first needs getting used to as the gear lever's natural plane is along 3rd to 4th, so a little guiding will be called for. Use too much force and one will find reverse and too little will find 3rd. However the action was fairly slick, needing a touch of deliberate action to engage. The pedal action has not been changed in favour of the hanging type and although fairly heavy, seem more progressive than before. The clutch action was notably smoother and a lighter when compared with the old Turbo.

Power assisted steering made light work of getting out of tight spots, yet it remained quite heavily weighted and had an excellent feel on the move with none of the floaty shimmy of the old suspension set-up to mar the new car's tracking ability. Somehow being the top notch performance coupe from Porsche, the weight of the steering could stand to be a bit more meatier as sports cars of this nature should be a bit unwieldly, difficult to conquer. This is of course a matter of taste and most surely Porsche had designed it this way to attract more buyers to the marque.

As familiarity grew, so did our confidence. The 911 Turbo could be hustled around the coastal routes of South France rather briskly. Although ground conditions switched from wet to dry continuously, the 911 Turbo gave little cause for concern, the new 17 inch Bridgestone Expedia S-01 mounted on new 17 inch "turbo" rims displayed excellent grip and behaviour despite their temperatures remaining cold throughout the journey. These new tyres from Bridgestone were on all the 911 Turbos there and they looked like the RE 71 Optima with wider drainage channels.

The turbo nature of the new engine gives the 911 a split personality. Drive it off boost and the car can be driven comfortably and sedately, thanks to the torque that is inherent to a large capacity (3.3 litre) engine such as the one found in the back of the Turbo. The gentler rise in the turbo pressure makes easier driving of mountain roads as there is less need to fear the on-off characteristic of a turbo-motor. However this is not to say that it less powerful. On the contrary. When the 911 shows its other side, few cars can keep up with it, let alone beat it. The boost may come in with less vengeance than the old 911 Turbo but when it gets on-cam between 4500 rpm and 6000 rpm, the acceleration generated by the new 911 is quite unmatched. The "rawness" of the old 930 Turbo, a characteristic of its turbo-motor is not so apparent as this new engine feels more mellow and refined. But this one endearing feature may well be the biggest hurdle the new 911 Turbo has to face when trying to win over the owners of the previous Turbo.

With the turbo at full chat, and one gear change later, the 100 km/h mark is dispatched in a scant but thrilling 5.0 seconds. Impressive figure that. But in truth, the 911 Turbo is only just getting into stride. The big helping hand of the turbocharger is more clearly felt in the upper reaches of the speedometer. The ability of this 911 to pass traffic is incredible. It is so easy, in fact too easy. One has to stomp on the ABS backed brakes once the overtaking manoeuvre is accomplished in order not to rear-end the car in front of you because the final speed after the overtaking manoeuvre is quite a lot faster than almost any car you'd care to mention.

While the engine characteristics are a subject for debate, the chassis refinement is not. It is clearly superior to the old 930Turbo, no doubt about that. According to the design team, there were several areas that contributed to the better feel of the new 911 Turbo. From the chassis point of view, it had to be strong and stiff and according to Hermann Burst, the Chief engineer of body development(also the 959's), the torsional rigidity of the 911 Turbo is second to none. No less important is the "rear axle kinematics" as the Porsche engineers call it, in other words, reaction to torque reversal or application. Where the old Turbo rewarded mid-corner power cuts with a frightening oversteer, the new one remains composed, non-threatening. Only higher up the range can it be coaxed to let go. The white knuckle, cold chill sensation is now put to rest and thankfully at that. It may thrill some, but not many. What Porsche has done is perhaps more geared toward good marketing rather than being purely technologically based. A good move although it may irk some purists.

The interesting bit here is the variable lock up limited slip differential made by ZF and Porsche. It looks like a Torsen diff but during cruising, it is almost locked up and in hard acceleration or deceleration, like in corners, it limits lock to 20%. Sounds like the Torsen cliff working in reverse.
Although our attention was drawn to the new rear differential, the cure to the oversteering characteristic probably came from the chassis which is based on that of the Carrera 2 and 4, so most of the handling prowess had been inherited and the Porsche engineers went one step further by fitting uprated dampers and springs. Travelling up and down small and poorly maintained mountain roads revealed just how hard and unyielding they were but more importantly, just how solidly built this 911 was. Sure there was some squeaks from the leather lined interior but not much, the bumps and ruts were felt more than heard. Low frequency bump- thump accompanied the jostling of the cabin's occupants but the seats provided extra damping as it probably tuned out much of the low frequency resonance from the chassis and suspension providing added comfort for the front occupants. On better roads, the suspension displayed the expected iron fisted control yet it relayed delicate feedback to the driver.

Where the road was clear and visible, the 911 was given its head. Enormous bags of acceleration meant that the approach speeds to corners were way above normal, this meant getting on the brakes really hard and earlier than usual. Wet roads resulted in the ABS doing their bit. A slight tugging at the steering wheel and a mechanical rumble indicated that the limits were reached and the ABS was in operation. Get into the right gear with a bit of double declutching, aim the car with the excellent steering, get back on the gas to balance the car's attitude. As the apex goes by, straighten out the steering and hit the accelerator. For a short while it seems the engine is leisurely pushing the car out of the corner then... wham! The biggest turbo push you'd ever feel shoving both occupants deep into the front seats.

The sensation seems to last a long time in 2nd, then just past 120 km/h, the engine hits the rev-limiter with a strong cut out, quickly snatch third and the relentless swath of turbo power continues. Totally addictive and a real ball of fun. But isn't it too easy? This is the legendary 911 Turbo we are talking about. How is it we emerge from a quick blast round the mountains still composed and not fatigued? Do this in a Lamborghini, Ferrari or even the old 911 Turbo and the driver will have worked up a sweat and felt like he had just gone for a 5 km jog. The passenger would also have worked up a sweat but it would be a cold sweat from fear of being added to the mountainside shrubbery at each corner.

Well wasn't this what the journalists cried for when they reviewed the old 930 Turbo? Less twitchiness and more real-world, on-the-road, press-on-regardless ability? Yes. And when Porsche delivered, we lament because only now do we realize just how endearing the old "cranky" character was. Having said that, the new 911 is a much better, more modern car. A traditional weapon to do battle with the new whiz-kids on the block, like the NSX, 348tb, 850i and 500SL. A car to put on your "life-time achievement" list but at what price?

Fast Facts

ENGINE
CAPACITY : 3299cc, M30 turbo
CYLINDER LAYOUT : Flat-6 boxer, air-cooled, K-Jetronic
VALVES : 12-valves, 2-valve heads
BORE X STROKE : 97x74.4 mm
COMPRESSION RATIO : 7.0:1
MAXIMUM POWER : 320 Bhp at 5750rpm
MAXIMUM TORQUE : 450 Nm at 4500 rpm

TRANSMISSION
TYPE : 5-speed manual G50 gearbox
DRIVEN WHEELS : Rear, Mechanical Differential

PERFORMANCE
TOP SPEED : 270 km/h
0-100KM/H : 5.0 seconds

SUSPENSION
FRONT : McPherson Struts
REAR : Semi-trailing arm

BRAKES
FRONT : 322mm ventilated discs
REAR : 299mm ventilated discs

TYRES
TYPE : Bridgestone Expedia S-01
SIZE : f: 205/50 ZR 17, r: 255/40 ZR 17

SAFETY
ABS : Yes
AIRBAGS : 2
TRACTION CONTROL : NA

MEASUREMENTS
LENGTH : 4250mm
WIDTH : 1775mm
HEIGHT : 1310mm
WHEELBASE : 2272mm
KERB WEIGHT : 1470 kg

Price in 1991: SGD $590,000
Number made : 3871 (1991-1992)
 

Summary
Photos: 
all content is intellectual property of motor-prime and cannot be reproduced in any form or manner without explicit permission from motor-prime. © 2004-2016 MotorPrime. All rights reserved.