SC at 40
It may have looked similar, but under the skin the Carrera 3.0’s replacement did bring significant advances. Total 911 studies the would-be last Neunelfer
2018 also marks the 40th birthday of the SC, so how did it evolve the 911?
This year marks not only the 30th anniversary of the 964, but also 40 years of an equally famous 911: the three-litre SC. Like the 964, the SC entered the world at a time of uncertainty for Porsche. The former was introduced by a Porsche impoverished by the collapse of its vital American market, the latter was confronted by California-inspired emissions standards which had hobbled traditional sports cars and completely wiped away the US muscle cars.
For the 2.7 1974 G-series Porsche continued its three-model policy which had begun in 1967. The 1976 911 offering, reduced to two models, comprised a 2.7 165bhp base and a Carrera bored out to 95mm for a capacity of 2,994cc. With K-jetronic, the subsequent three-litre Carrera packed 200bhp, and enthusiasts noted that for the first time a new Porsche model boasted fewer horses than its predecessor.
For the 1978 model year Porsche announced a further change: there would now be only one naturally aspirated 911 – the SC – available once again as a Coupe or Targa. Such rationalisation made sense for a company now producing no fewer than four models: besides the 911 was the Turbo, now well established; the entry-level 924, despised by purists, but for several years the best-selling Porsche in the UK, and the 928, which won the 1978 Car of the Year. Weissach had also become a research hub like the K on st ruk ti onsbüroo fold: once devoted entirely to Volkwagen, Porsche was forced to diversify after 1973 when Wolfsburg tore up its long-standing exclusive development contract. By 1977, Weissach was working on any number of confidential projects both inside and outside the motor industry, and these generated at least a quarter of the company’s income.
Nevertheless, the 911 would not be neglected, and although it looked virtually identical to the threelitre Carrera, much redesign work had gone into the new 911 SC: externally the width was increased by an inch and a half thanks to wider rear arches, although rims at six- and seven-inches and tyre sizes were unchanged. Underneath, the rear anti-roll bar was now 18mm, and at the front it went from the Carrera’s 3.0’s 16mm to 20mm as Porsche sought to reduce the inside front wheel’s tendency to lift in hard cornering. For the first time, a 911 featured servo-assisted brakes. Most magazines thought Porsche had struck the balance between feel and sensitivity, but one or two lamented the passing of the un-servo’d variety, much as they would the passing of unassisted steering ten years later. Indeed, the only drawback of the new brakes was the space the servo took up under the bootlid, and inveterate traveller Paul Frère specified his 911 without braking assistance when he ordered a late-production SC (which also had a 3.2 engine).
But if cabin changes were limited to oil pressure and temperature gauges which lost their numbers and instead received coloured fields, the flat six underwent substantial revision. Although inheriting the 95x70.4mm bore and stroke of the Carrera and its 8.5:1 compression ratio, the SC now used the thicker crankshaft and main bearings of the 3.3 Turbo, but thinner connecting rods. The Turbo’s breakerless ignition, which worked better with K Jetronic than traditional points, was also introduced, as was for good measure an electronic rather than mechanical cut out for the rev limiter. The emphasis was on improving drivability and economy through better torque, and although nominally less powerful than the Carrera three-litre, judging from the enthusiasm with which the SC responded to the driver’s right foot, it seemed to go just as well despite its stated maximum power of ‘only’ 180 bhp at 5,500rpm; its maximum torque was significantly better than the Carrera’s. Rounding off engine developments was an eleven- rather than fivebladed fan which reduced cabin noise, and a proper oil cooling radiator rather than the previous, less efficient serpentine variety. Porsche said this would allow maximum speed running for 30 minutes.
In the US, the SC was greeted with enthusiasm. Deprived first of the 2.7RS, then the Carrera 2.7
MFI (and from 1979 the 911 Turbo), the Americans were at the start of three decades where emissions regulations meant the fastest 911s would not be allowed to enter the country. The advent of the SC, which in catalysed form offered at least 175bhp, meant a much livelier 911 than the federalised 2.7 which had preceded it. The US SC’S 258Nm of torque, a 10 per cent improvement, was much appreciated too.
In Europe, Porsche purists were concerned that once again a 911 announced fewer horses than before. It mattered less in Great Britain, where if the SC had to yield 10mph in top speed to the 30 per cent more expensive Ferrari GTBI, it showed the Italian a clean pair of heels to 60mph. Comparing it with the Lotus Esprit, Maserati Merak and the 308GTBI, Autocar said: “If you want blistering initial acceleration, beautiful finish, long service intervals and can live with its inconsistent handling, then the Porsche SC
may be your car.” Auto Motor & Sport’s
analyses showed there was little performance difference between the 200 horsepower Carrera and the 180bhp SC,
0.2 and 0.8 seconds to 100kph and 160kph respectively and a 5mph-lower top speed;
AM&S too liked the torque and better response of the now all-electronic ignition. But the deficit opened the way for tuner Alois Ruf and Porsche dealer and racer Max Moritz to offer 200bhp-plus tuning packages. Between them they sold about 500, and Porsche countered with a discreetly marketed tuning kit of its own, but the SC would soon evolve up the power scale, rendering these tuned or ‘Powerkit’ versions redundant.
For MY1980, Porsche announced that output had increased to 188bhp, and the compression ratio was also raised fractionally to 8.6:1. It was far from evident where this extra power came from, and subsequently it was believed that Porsche had deliberately understated all the SC’S performance statistics and indeed bridled the first SC to an official 180bhp so that its top speed would be lower than the new, but conservatively engineered 928 V8 flagship which yielded only 240bhp and weighed some 250kg more than a 911.
“The 911’s popularity never waned: a 1979 AM&S poll indicated that 83 per cent of readers thought the 911 was the most important Porsche model”
Although 928 advocate Ernst Fuhrmann had said that as soon as 911 demand fell to less than 6,250 per year, it would be programmed out, the 911’s popularity never waned. A 1979 AM&S poll indicated that 83 per cent of readers thought the 911 was the most important Porsche model; the 928 gleaned only 3 per cent. Given such a vote of confidence, Weissach was already quietly developing the next iteration of the SC even before Fuhrmann left the company in autumn 1980. This took advantage of better availability of 98 RON to improve combustion efficiency, with faster ignition timing and a compression ratio raised to 9.8:1 (which demanded premium petrol). Now offering 204bhp, in AM&S’S test the latest SC shaved half a second off the 0-100kph time and managed a top speed a shade under 150mph.
This boost coincided with the arrival of Peter Schutz and his famous renewal of faith in the 911, which also led to the development of the model so sorely missing on the US coasts: the 911 Cabriolet. This was the car that fresh air fiend Helmutt Bott had simply been waiting to make, but which, like his Speedster project, had fallen foul of the Fuhrmann Verbot. Chassis flexing was the technical reason for abandoning an open 911 in 1965, but an experimental build 924 cabrio had subsequently proved entirely satisfactory. Though the open 924 design was not taken up until the 1989 944, the transmision tunnel conferred the necessary structural stiffness. For the 911 this meant a strengthened floor which, combined with construction techniques which had improved significantly since the sixties, enabled the 911 Cabriolet to become a reality. Work proceeded quickly and within four months of his arrival, Schutz was able to admire the first prototype. The Cabriolet was announced to great acclaim at Frankfurt in 1981 and prototypes tested extensively during that winter allowed Porsche to make this a MY 1983 model. Although the hood was still manually operated (an electric version would take another four years) this did not diminish the desirability of this open 911 and over 6,000 SC Cabriolets were made before the SC gave way a year later to the 3.2. Porsche was also pleased with the SC’S drag coefficient: roof-up, the SC managed 145mph and roof down lost barely 9mph.
Finally there was, right at the end of SC production, a little known Rennsport version: although Porsche’s competition thoughts in the early eighties were very much around Group B and four wheel drive, Jürgen Barth persuaded Bott to allow him to build a 911 customer racer. A shell lightened with aluminium doors and bonnet, glassfibre bumpers and a simplified interior in a weight of 1,050kg. With forged pistons, the compression ratio raised to 10.3:1 and carburation handled by mechanical fuel injection, the 3.0-litre developed an easy 250 bhp at 7,000rpm and scope to go to 280bhp. Named the SC RS, this was an explosive performer which did well in European tarmac rallies and, prepared by Prodrive, won the Middle East Rally championship three times. Alas, it being classified as an ‘evolution model’ meant that Porsche needed to build only 20 to gain homologation status, making the SC RS, with only 22 examples worldwide, Porsche’s rarest ever Rennsport.