The History of Porsche by James Jones

Porsche

After retiring from Rallying for two years after the 1978 Safari Rally, the Porsche engineers concentrated on development of the new 924 range to create the GT and Turbo models.

Officially launched in November 1975 the 924, born from an abandoned VW-Audi project, was marketed as the “ entry -level “ Porsche. Unlike previous Porsche models this car was front-engined, water cooled and shared many of its components with current production Volkswagen and Audi vehicles. Indeed the engine and gearbox were supplied by Audi, the same block powering Volkswagen’s sturdy LT vans!

Due to the model’s heritage and construction, Porsche purists were quick to condemn the car as “not a real” Porsche but by October 1979 the 924’s 1984cc four cylinder engine was offered with forced induction. The Turbo had arrived and with it, true performance.

Back in January of that year privateer and works supported Rally driver Jurgen Barth had intended entering two pre-production Datacom sponsored Turbo cars in the Monte Carlo Rally but due to a steel strike production was delayed and the Turbo missed the homologation deadline. The two cars were converted back to standard 924’s and Barth finished 20th overall.

Later in that year after the 924 received it’s homolgation Barth entered two cars into the gruelling Safari Rally. The two cars were too heavy to be truly competitive, running standard 170bhp engines and the pair retired.

In true Porsche tradition the 924 spawned special limited edition variations, namely the Carrera GT, GTS and GTR. The Carrera GT kept the basic front engine -rear drive (the gearbox was mounted in the rear trans-axle for optimum weight distribution) 2+2 hatchback style, steel unit – construction monocoque shell. It also kept the same VW/Audi engine.

What it did have added, however, made it into a very special vehicle indeed. The engine became intercooled to allow an increase in power from 170 bhp to 210 bhp. The crankshaft was strenghened, compression ratio increased and the cylinder head was reworked. Due to the air-to-air intercooler being mounted above the rocker cover a very large aggressive looking vent was added, off-centre, to the bonnet. Wider rims resulted in beautifully flared polyurethane wings on the front (carried over to the later 944) and rather less attractive but more aggressively styled group 4 wing extensions to the rear of the same material. The interior’s black pin-striped velour seats with red-piping and deep pile black carpeting cosseted the driver and lurid Carrera graphics on top of the off-side front wing and under the large tail spoiler warned off any would-be boy racers!

The motoring press rated the Carrera GT very highly, not surprisingly. In 1981 there weren’t many vehicles capable of 0-62mph in 6.9 seconds, a top speed of 150mph and could return an average of 30.1mpg! All 75 right hand drive cars of the four hundred built to satisfy Group 4 racing regulations sold immediately and the GT remains one of the rarest Porsches available. Even rarer still are the GTS and GTR, built for “special” customers. The GTS was up-rated to 245bhp whilst the GTR boasted 375bhp. Both cars were only available in left-hand drive, both had perspex covers instead of the pop-up light assembly and if you wanted a GTS it came red in colour, a GTR, in white.

The Carrera’s weren’t hugely successful in motorsport but there were some notable results. At the start of the 1981 season Walter Rohrl was, unbelievably, un-employed so Porsche swiftly signed him up. The GTS was developed with Almeras in France, resulting in homologation into Group 4 on 1st March 1981, homologation number 672. Although its first Rally outing was on the German Metz Rally its first International outing was on the 1981 Tour de Corse Rally in the hands of Jacques Almeras. Unfortunately he retired after an accident. A week later Walter debuted the Schmidt Motorsport prepared GTS in Germany. Throughout the middle-part of 1981 Rohrl campaigned the GTS in the German National Championship, scoring victories on the Hessen Rally in June (a round of the European Championship), the Serengeti-Safari Rally (still in Germany !) in July, the Vorderpfalz Rally in August and the Sachs Baltic in September. He had enough points to win the Championship by then but Porsche were also supporting German driver Hero and by October Rohrl was out of the GTS and back in a works entered 911 for the San Remo Rally, the first works entry since the 1978 Safari.

This return to the 911 in Rallying effectively ended the 924’s Rally career, although Jurgen Barth and his co-driver Roland Kussmaul finished a very credible 10th overall on the 1982 Monte Carlo Rally in their Group B GTS, but the 924 went into retirement. The 924 also proved itself a worthy circuit racer at the 1981 Le Mans race. Barth and Rohrl partnered a 924 GT turbocharged twin-cam prototype into 7th overall and collected a prize for the car spending the least amount of time in the pits, they made no unscheduled stops and averaged 114mph round the circuit.

Porsche 924 Carrera GT Road Specification:

Bodyshell; Steel unitary construction 2-door hatchback coupe, Zinc coated.

Polyurethane front wings and rear wheelarch extensions.

Engine; VW/Audi 4-cylinder in-line water-cooled. Iron block, light-alloy cylinder head. Intercooler and KKK Turbocharger. Belt-driven single overhead camshaft, 8 valves. Five main bearing crankshaft. Bore 86.5mm x 84.4mm, capacity 1984cc, compression ratio 8.5:1. Bosch K Jetronic fuel injection. Digital ignition. Power 210bhp @ 6000rpm, torque 203lb/ft @ 3500rpm.

Transmission; Manual: engine mounted clutch, rear-mounted Porsche 5-speed, direct top gearbox and standard differential. Optional limited slip differential.

Suspension; Front: Uprated and strengthened VW 1303 MacPherson struts, coil springs. Uprated and strengthened Golf lower wishbones.

Rear: Uprated and strengthened VW 1303 Semi-trailing arms, transverse torsion bars.

Front and rear anti-roll bars. Bilstein gas filled shock absorbers. VW rack and pinion steering.

Brakes,wheels, Ventilated discs front and rear, servo. Standard: Fuchs 7J x 15 tyres; five stud forged aluminium rims, 215/60 VR Pirelli P6 tyres.

Optional: Fuchs 7J x 16 with 205/55 VR 16 Pirelli P6 tyres front. Fuchs 8J x 16 with 225/50 VR 16 Pirelli P6 tyres rear.

Dimensions; Front track 1477mm. Rear track 1476mm. Width 1737mm. Length 4320mm. Height 1270mm.

Performance; 0-100kph/62mph 6.9seconds. Maximum speed 240kph/150mph.

Price in 1980; UK £19,211.

Porsche 924 Carrera GT Production

Model Year of Construction Number produced Capacity and Power

924 Carrera GT; 1980 400 No. 2ltr 210bhp

06 No. 2ltr Prototypes

GTS/GTR 1981 40/19 No. 2ltr 245bhp/375bhp
Porsche – The Group B Era (Part 2)

Although the Porsche factory team concentrated their efforts on the 924 in the early eighties the ubiquitous 911 never stopped racing and rallying and winning in the hands of privateers. Notable results came from cars prepared by the Almeras Brothers and Jean Pierre Gaban. The 911 was first homologated into Group 4 on the 1st March 1973, homologation number 3053. These were the 2.7 litre engined cars which made way in 1975 for the new 3.0 litre SC models. Whilst Stuttgart experimented with the 924 the private teams running 911’s had had years of development under their belts and consequently even though the design was over 18 years old in the right hands they were devastatingly quick.

The dawn of the Group B Era started at the 1982 Monte Carlo Rally and in the face of new Group B machinery such as Audi’s new Quattro the Group 4 Porsche’s looked outdated. The event proved to be the start of Walter

Rohrl’s historic three consequative Monte wins in three different cars , this time in an Opel Ascona 400. It was a remarkably dry Monte that year which is possibly why Mikkola finished second in his Quattro and third and fourth places went to Jean-Luc Therier and Guy Freqelin respectively in their Almeras Porsche 911SC’s. Fifth and sixth places were filled by semi-works Renault 5 Turbo’s. Although the Porsches did very well on the Monte by the end of 1982 “the writing was on the wall”. To compete in Rallying at World Rally Championship level Porsche would have to improve their existing car or design a new one .

What they actually did over the next few years was both! Porsche took advantage of Group B regulations which allowed an evolution run of twenty vehicles (10% of the Group B production 200) and effectively made an evo model of the SC. This was the 911 SCRS all of which were sold privately whilst the factory concentrated their efforts on the new model 959. There were more than 200 911 SC’s manufactured of course.Including Targa’s, Porsche built 61,828 3.0 litre model 911 SC’s. Limited run 911 specials have always sold like hot cakes and the SCRS was no exception. Some of the twenty went into private collections but seven were bought by the heavily financed Rothmans Rally Team and preparation and running of the cars was entrusted to Dave Richards’s Prodrive company.

Whilst production and development of the SCRS went on, the 1983 season saw only two successes in European Rallying. The German pairing of Klausner and Zeltner won the Yugoslav Rally in their Group 4 car whilst the Saarland Rally in Germany was won by the aptly named Hero in a Group B 911 Turbo. It wasn’t until 1984 that the SCRS showed it’s metel.

The old Group 4 911’s used the standard steel Coupe shell with bolt on fibreglass arches front and rear and the familiar “duck – tail” spoiler. The oil cooler was mounted in the front bumper just like the previous 2.7 and 3.0 litre RS models but other than these visible differences to a standard SC they weren’t hugely different as the specification below shows:-

Porsche 911 SC Group 4 Rally Car

Engine: 2994cc, 12 valve, single over head camshaft per cylinder, air cooled Flat 6, Bore/Stroke 95/70.4, Compression Ratio 10:1, Induction by Kugelfischer injection, dry sumped. Power 280bhp at 7600rpm, Torque 27.7Kg/m.

Transmission: Single plate clutch, Porsche 5 speed gearbox, rear wheel drive.

Steering and brakes: Rack and pinion, 300mm ventilated discs front and rear.

Suspension: Front – MacPherson strut, Rear – Semi-trailing arm and torsion bar.

Dimensions: Length 4291mm, Width 1778mm, Height 1300mm, Wheel base 2272mm, Front track 1437mm , Rear track 1462mm, Weight 960 Kg.

The SCRS was a lightened, strengthened and more powerful version of the preceeding Group 4 car. The engine was the same Flat 6 but bored to 2996cc. Other modifications included a high lift cam, a 935 model cylinder head incorporating hollow valve stems with suface treated valve springs, cup tappets and although the bore and stroke remained unaltered, the compression ration was mildly increased to 10.3:1. Induction was by mechanical injection of both Bosch and Kugelfischer origin . The oil cooler was moved to the offside front wheel arch and the oil pump modified. A special twin exhaust gave an extra 10bhp, in the countries where it was legal !

The factory caged bodyshell used was from the 911 Turbo but the front and rear bumpers, boot, bonnet, doors and front wings were all made in GFK aluminium. Further weight saving came from lightweight glass and aluminium rear axle arms, protected by a steel plate. The rest of the suspension was strengthened including Bilstein coil overs at each corner. Interestingly the front apron carried two vents ducted to the ventilated discs, but the offside brakes had to wait for the cooling air to pass through the oil cooler first.

The 5 speed transaxle remained running a direct 5th gear with optional ratios of 4.375:1 or 5.286:1 allowing maximum speeds of 133mph or 124mph. The Fuchs forged alloy wheels found on the Turbo model were adopted for the SCRS, 7J x 16 on the front and 8J x 16 on the rear.

The information above refers to the rally car. The extremely rare road going version of the SCRS differed slightly from it’s competition twin. The 290bhp rally engine was “detuned” for the road to 255bhp and ran Bosch Motronic electronic injection. The direct fifth gear was changed to 3.875:1 to give an overdrive top gear. In true Porsche lightweight tradition rear seats were omitted, manual window winders were fitted and competition seats with four point harnesses came as standard. The only visible reference that this car was in fact an SCRS decal across the rear screen but from behind, the “whale tail” Turbo spoiler obscured it. Even with the power reduction to 255bhp the road car was exceptionally quick, 0-30 in 2 seconds, 0-60 in 4.9 seconds, 0-100 in 12.3 seconds, a standing quarter of a mile in 13.5 seconds and a top speed of 160mph demonstrate just how quick.

The Rothmans Team cars are probably the best remembered 911’s from the Group B period mainly due to their vivid blue and gold livery, the people who drove them and the giant killing results they achieved. The 1984 season saw the pairing of well known co-drivers Juha Pironen and Ian Grindrod with the driving genius of Henri Toivonen. Henri’s flambouyant driving style in the 911 was a sight to see and the season‘s efforts were rewarded with outright wins on the Costa Smeralda, Ypres and Madeira Rallies securing the runner – up position in the European Rally Championship. Droogmans and co-driver Joosten also won three European Championship rounds that year in their Belga sponsored, RAS Sport run SCRS.

Group B was in full swing by the 1985 season and as mentioned previously, the SCRS was, design wise, a little long in the tooth. However,Prodrive and the Rothmans Team proved on the Tour de Corse Rally that what actually matters in Rallying is ultimately speed, but backed with reliability, ruggedness and consistency.

French men Beguin/Lenne and Irish duo Coleman/Morgan finished overall in third and fourth places respectively. When you look at the opposition on that Rally it puts their performances into perspective and you realise what a remarkable effort was made. In front in first and second position were Ragnotti in his 5 Maxi Turbo followed by Saby in a T16 Evolution 2. That shows the calibre of the competition, but apart from Lancia withdrawing their 037’s due to Bettega’s untimely death, they out lasted two other T16’s, one Audi Sport Quattro and two other Maxi 5 Turbos. An old design it may have been but still competitive.

As the Rothmans Team again showed in the Middle East Rally Championship. Consistent driving from Saeed Al Hajri and co-driving by John Spiller secured the 1985 Championship. The pairing also managed a credtable 5th overall on the gruelling Acropolis Rally that year.

Throughout this period the Porsche engineers were developing the 959, without the knowledge that the following year Group B would be over. As so often before though, the Group B “anything goes” rules were about to produce a quite remarkable sportscar.

 

Porsche – The Group B Era (Part 3)

The idea for the 959 was born a few months before the 1983 Frankfurt Motor Show and the public saw the first one two years later at the 1985 Frankfurt show. This was a remarkable achievment for Porsche, in particular the 959 development engineers at Weissach in Germany, as it usually took Porsche seven years to take a design to production. But then again, everything about the 959 was remarkable.

After much debate the Porsche Board of Directors decided that due to the huge production costs they might as well make the 959 into a technical milestone. This led to a sequential twin – turbo system on the engine, electronic transmission control, variable ride height, lightweight composite body components, advanced aerodynamics and state of the art safety features like tyre pressure monitoring.

Each 959 built started life as a galvanised 911 Turbo bodyshell with a heavily modified floorpan, engine bay and front – end cell to take the four wheel drive system. The doors and front bonnet were kept in Aluminium but most of the other panels were made of polyurethane, Kevlar, Aramid and glass – fibre – reinforced RRIM or Autoclave mouldings . The use of Steel, Aluminium and new age materials like Aramid (same tensile strength as steel but eight times lighter) in car body construction had never been tried before.

As you would expect from a vehicle based on a 911 the 959 kept that family shape but the body shell was much softer in appearence.Wind tunnel research led to a more rounded front end with an intergrated bumper slatted to allow cooling for the water radiator, oil coolers and slatted vents at the corners for brake cooling. A duct, behind each door, in the rear arches fed air to the air – to – air intercoolers and by the time the passing air over the car had reached the rear it had to pass through a large, blended into the bodywork, spoiler.

The underbody of the 959 was completely encased. All this attention to aerodynamics resulted in the 959 having a relatively low drag coefficient of 0.31 but more importantly on its lowest suspension ride height setting (automatically activated at 75mph plus ) the 959 had zero lift.

The zero lift aspect was another in a long list of technically advanced safety features. As well as Dunlop Denloc wheels with hollow spokes filled with pressurised gas to indicate any wheel cracking through sensors

( taken from the 956 GT cars ) Dunlop supplied D4 tyres which used the Denloc bead retention system. Wabco / Westinghouse developed a four channel anti – lock braking system and a “ Securiflex ” bonded in windscreen could protect the passengers from bluebottles to bullets !

As mentioned earlier the ride height was adjustable to allow the driver to negociate obstacles such as ferry ramps. The options available were 180mm, 150mm or 120mm, the adjustment activated by Fichel and Sachs hydropneumatic springs. These were in addition to the eight Bilstein monotube dampers, supporting wide based wishbone suspension at each corner.

The 959 had a complicated , yes you’ve guessed it, electronically controlled four wheel drive system which utilised the ABS system for wheel monitoring. As well as regulating drive to each wheel the system could sense acceleration and therefore weight transfer and would vary drive front to rear from a 40 / 60 slpit to a 20 / 80 rear bias.Fascinatingly Porsche research into four wheel drive had found that by increasing the rolling radious of the front wheels by as little as one per cent the resultant change in gearing assured that the car was always pulling from the front. This in turn gave greater straight line stability, critical at the high speeds the 959 could sustain.

Probably the most innovative feature of the 959 was the engine. The ubiquitous flat-six engine mounted at the rear displaced 2.85 litres, produced 450bhp and could run on 95RON unleaded fuel. The cylinder heads were water cooled whilst the cylinders remained air cooled. The crankshaft and rods were made of Titanium whilst the camshafts which operated four valves per cylinder by hydraulic lifters, were driven by a duplex chain. KKK supplied Porsche with turbochargers with water cooled bearings, each 959 having a smaller and a larger one. The smaller one looked after the air flow levels to just over 4000rpm, at which point excess exhaust gasses were already “spinning – up” the larger right – hand turbo to the point where a compressor cut – in valve opened allowing supplementary air to mix from the first turbo and meet the necessary air flow levels at the top end. The sequential turbo set-up was so effective that you could hold the right hand exhaust, fed by the larger turbo, after lengthy idle and it would be stone cold ! Peak torque was a mighty 370lb / ft at 5500rpm on maximum turbo boost of 14psi. The engine red – lined at 7800rpm.

Most of the clever parts of the engine were based on experience gained in GT Racing but the sequential turbocharging and the four wheel drive system were unique to the 959 and consequently, a Porsche road car.

The 911 engine has always been rear mounted, the gearbox positioned under the rear seats, facing towards the front of the car. As you can imagine this layout leant itself to four wheel drive. Porsche attached a shaft forward of the normal output of a special six – speed gearbox, to give front wheel drive, inside a torque tube. This tube was bolted solidly to both transaxles also used in the works Audi Quattro’s – and front differential casing, which housed the torque – splitting clutch. Bolting the drivetrains together maintained accurate driveline running and had the added benefit of increased strength in the unfortunate incident of a frontal impact. A continuously operating sintered steel / plain steel multi- plate clutch in both differentials split the torque front – to – rear and vice versa. As mentioned earlier all the drive was electronically controlled andhelped deliver devasting performance.

Bearing in mind that the interior of a 959 was virtually identical to a standard 911 turbo except for a few extra guages concerning the four wheel drive system etc.What would you expect from a car that in 1987 cost 420,000DM ( £141,500) ? From a car which if you had to replace a single microprocessor, would cost as much as a Volkswagen Polo ?

Well it’s hard to put into words but here goes:- 0 – 60mph in 3.9 seconds. A top speed of 197mph. To put it into perspective, you could sit idling at the side of a road and allow a vehicle to pass you at 100mph, set off yourself and pass it inside one kilometre ! More importantly to Porsche ideaology, all this performance was available in a car that was un – tempremental, reliable, safe and as anyone knows with a Porsche, you could do it over and over again.

Porsche 959 Road Car Specification

Engine and gearbox :-

Flat six boxer configuration, 2850cc, 4 valves per cylinder, twin overhead chain driven camshafts, aluminium head, aluminium block, bore 95mm, stroke 67mm, compression ratio 8.3 : 1. Porsche derived six speed gearbox driving all four wheels. Max. power 450bhp, max. revs. 7800rpm, max. torque 370lb / ft at 5500rpm.

Suspension and brakes :-

Front : twin wishbones, coil springs, anti – roll bar, vented discs linked to ABS system.

Rear : twin wishbones, coil springs, anti – roll bar, vented discs linked to ABS system.

Steering :- Rack and Pinnion.

Wheels and tyres :-

Front : Porsche five spoke design alloys, 8.0 J x 17 ”, 235 / 45 VR 17 Dunlop D4 tyres.

Rear : Porsche five spoke design alloys, 10.0 J x 17”, 255 / 40 VR 17 Dunlop D4 tyres.

Dimensions :-

Length : 4260mm, Width : 1840mm, Height : 1280mm, Wheel base : 2300mm, Front Track : 1504mm, Rear Track : 1556mm, Kerb Weight : 1350Kg.

Build :-

Approximately 250 vehicles built between 1986 and 1987, of which 50 cars were “ Lightweight ” Sport spec. and 20 were pure competition cars. The Lightweight Sport cars in comparison to the standard “ Comfort ” Sport specification managed without air conditioning, ride height control, rear seats, reduced sound deadening material and offside mirror ( handy in the U.K. ! ) saving 100Kg.

Competition History

The 959 only really saw competiton success in gruelling “Raid” type rallys such as the Paris – Dakar Rally, competing both in 1984 and 1985. The 1984 entry was to all intents and purposes a four wheel drive 959 but ran with a 911 Carrera powerplant and bodyshell for reliabilty reasons. These Rothmans entered cars, three in total, two main entries and a support car, had a massive 11” ground clearence . After 6800 miles in just 20 days the team finished 1st, 6th and the back – up car 26th overall.

The 1985 entry, like the previous ’84 event, was a private entry put together by Belgian Jacky Ickx with both Porsche and Rothmans support. This time the cars were proper 959’s, however, they ran with normally aspirated engines and without electronically controlled four wheel drive. Porsche Chief Engineer Helmuth Bott was qouted as saying “ We would have entered the improved version of last years car, but a thorough test was more important than our role as favourites. If our primary consideration had been overall victory we would have played it safe ”. All the 959’s retired, Jochen Mass roled his, Rene Metge demolished an oil line in a spin and Jacky Ickx hit a sand obscurred boulder at 110mph ! In reality none of the failures mattered because the Porsche development department had got the necessary data they required and Porsche had already won the previous year.

Later in 1985 Porsche entered the Pharaos Rally with a two car team, one prepared in Germany and one prepared by Prodrive in the U.K. for Rothmans driver Saeed Al Hajri. The German car was destroyed by fire on the first day but Al Hajri won the event easily. These were full blown, twin turbo, electronically controlled rally 959’s.

The 959 ( in competition form I should really refer to it as a 961 ) in 680bhp race trim, finished seventh overall in its first attempt at the Le Mans 24hour race, but the 959, just like the Ferrari 288 GTO, designed with Group B competition in mind, missed the opportunity to do further competition after the ban in 1986 and what we are left with, as ever, is a truly remarkable, rare road going homologation special.

Author: James Jones

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