Impact Bumper Porsche 911 Group Test

The impact bumper 911 series generated more landmark cars than any Porsche model range before or since. We recently gathered ten excellent examples together for a back-to-back test, to profile their progression from self-conscious stand-in to puff-chested powerhouse. John Glynn reports.

Impact Bumper Porsche 911 Group Test

The story of the impact bumper 911s is often told in derisory tones. Faced with unavoidable new safety and emissions legislation in the critical American market, Porsche apparently ruined its rear-engined rebel by fitting chunky bumpers and clunky fuel injection, exorcising the soul of the machine in the process. Nothing could be further from the truth.

Rather than emasculating the much-revered original, the impact bumper (IB) cars built on the appeal established by their illustrious predecessors, and went on to achieve great things in their 16-year lifespan: spreading the Porsche gospel to a much wider audience, and pulling the 911 back from the brink of extinction. Our journey begins in March 1974, when the immaculate Orange 911S seen here was delivered to its first owner.

2.7 Carrera in Bright Yellow Group Shot 1 Magazine Cover in Progress

From 1974, the standard production line-up went from entry-level 911, to 911S and Carrera, rather than the T, E and S of previous years. All engines on offer for the 1974 model year displaced 2.7 litres, and the increased capacity meant more power. The 150bhp base 911 had 20 more horses than the 911T, the mid-range 911S had 175bhp against the 2.4E’s 165, and the 2.7 Carrera used the same 210bhp 911/83 engine as the classic ‘73 Carrera RS.

Retaining mechanical fuel injection on the 2.7 Carrera meant that, due to stringent new exhaust gas legislation, the car could not be sold in America. Instead, the company were forced to fit pollution-complaint detuned S engines to Carreras sold in the USA, until the model was eventually phased out in 1975.

The new 911 and 911S engines used much cleaner Bosch K-Jetronic fuel injection, but they were not the first 911s to do so. The Continuous Injection System had also been fitted to the last US 911Ts, the so-called 1973.5 cars. K-Jet was a great leap forward, giving better economy and lower emissions and, with the 1973 fuel crisis still fresh in peoples’ minds, K-Jet ensured that the ’74 cars remained an attractive ownership proposition.

Attractive is a word not always used to describe the impact bumper cars, but the clean profile created by the curved aluminium bumpers agrees with me entirely. While most other manufacturers struggled to integrate the new American legislation on minimum bumper heights, Porsche pulled off a design coup that still looks crisp, well over thirty years later.

First-year IBs predate the galvanising introduced during 1975 and 1976, and many have succumbed to the vagaries of rust; historically low values endearing them to precious few saviours. As a result, the 911S is now an increasingly rare and valuable car on this side of the Atlantic. Neil Thackray’s stunning 911S has recently completed a thorough nut-and-bolt restoration. The car also featured on the front cover of the Haynes manual (the blue version), so we are truly in the presence of greatness.

Neil’s 911 is perfectly painted in colour number 156, known simply as ‘Orange’, and the restoration is a work of art. From the orange-edged floor mats, to the rare and unusual right-sided rear wiper linkage, every detail is beautifully measured: clean enough to know it has been attended to, but not coated in overkill. Peter Andrews, here in a lovely Yellow 2.7 Carrera, remarks upon the “earliness” of the pristine Porsche, and the subtle steps involved in the transformation from early to impact are revealed. The same is true behind the wheel. Even with a running-in rev limit, driving the box-fresh ’74 feels very similar to an early car, with one real difference: the seat height.

Popular opinion suggests that the change from early to IB had a substantial impact on weight, turning cream cracker into dumpy doughball. This is not the case. The bumpers and their mounts added modest ballast to the tub, but slimming the battery count, and swapping steel trailing arms for aluminium mitigated the increasing girth. New seats were also responsible for a reduction, at the expense of a slightly higher driving position. Thanks to these weight-saving solutions, the early impacts were only negligibly heavier than their pre-‘73 equivalents.

It’s time for some cornering shots, and top of the list is the exceptionally original Light Yellow Carrera, currently for sale through Peter’s company, Transend in Cambridgeshire (http://www.transend.co.uk/). The flat six snaps instantly into life, the exciting pulse of the 2.7 RS engine amplified through a pair of SSI heat exchangers, and a lusciously rakish bark echoes through the woods surrounding us.

Neil Dickens and I exchange wry smiles as, last time we met, Neil was the proud seller of a Lime Green ’74 Carrera that made the same raucous racket, and he recently filled the space left in his showroom with another 2.7, this time in Black. To say Neil likes these cars is an understatement.

Peter’s wife, Litte, is just as enthusiastic when it comes to the 2.7s, likening the Carrera to her early 356. “They both feel so alive and exciting”, enthuses Litte. “I love driving this 911: it is such a comfortable, usable car but also, just so fast”. I agree it is impossible not to instantly warm to the car’s go-anywhere, race-anyone character, and I briefly daydream a lap around Spa in the custard Carrera.

Jack Wilson jolts me back to reality, with a jangle of the keys to his Carrera 3.0 Targa. Introduced in 1976, the Carrera 3 ran for just two years: two years during which it established quite a reputation. Autocar eulogised its “horizon-grabbing acceleration”, and Auto Motor und Sport found the car notably quicker than the 2.7 Carrera it replaced: a full two seconds faster in the fourth-gear charge from 50-120 km/h.

Fellow C3 owner Jack has enjoyed this gleaming Silver Targa for an amazing 21 years. As with the 2.7, the ride quality is comfortable but not soft, though the Targa feels less direct on turn-in for hard corners, due perhaps to the bigger 16-inch Fuchs on original tyres, the slightly taller ride height and the moderately heavier bodyshell. The rebuilt engine pulls every bit as well as expected, and the familiar forward thrust available under my right foot is absolutely addictive.

In 1977, the normally aspirated 911 range was reduced to one model: the 911SC. Despite glowing reviews, journalists began writing about the 911’s future in distinctly funereal tones. Concurrent to calling the SC “an exercise in driving euphoria”, Car and Driver decided “there can’t be many too years of life left in the 911 series.” Car editor Mel Nichols said “I won’t be among those who mourn when the 911 finally is no more”, and Wheels declared, “the 911 belongs to another era, so let’s put it out to pasture before it breaks down.”

Porsche had made no secret of plans to scuttle the 911 in favour of the 928. But when legions of loyal fans kept SC sales firmly afloat, the Company had to concede the error of their ways. Once 911 development was resumed, horsepower began to climb, and when the 204bhp motor was introduced in 1981, the SC finally had more power than its predecessor.

Famous for bulletproof reliability, and exceptional value for money, the SC is a regular route into 911 ownership, and both of our SCs were bought as first 911s. Though SC prices are rising, Marcus Dullea’s Minerva Blue ’79 Coupe is a great example of what can still be found for reasonable money. Marcus bought this left-hand drive non-sunroof coupe a few months ago for just under £8,000, an absolute bargain for such a clean car, albeit with a few small jobs to do. Behind the wheel, the SC is a delight to drive. Though not quite as savage through the gears as the C3, the magical motor is awash with grunt, pulling cleanly from tickover revs in top gear.

Offered for just one year before the 3.2 Carrera replaced the SC, the simple, lightweight SC Cabriolet is a driver’s car par excellence, and the model was sold out two years in advance. The punchy 930/10 engine gives a sub-six second 0-60 time and, as Georg Kacher said when he drove the Cabriolet for Car magazine, the car puts you “at the very core of fast motoring”. Having owned my Grand Prix White example for almost four years now, covering many memorable road trip miles, and even a track day or two, I couldn’t agree more.

IB evolution continued with the introduction of the 3.2 Carrera in 1984. The new car boasted more power, thanks mainly to higher compression and Bosch Motronic engine management, which again upped the bar for emissions and economy. The 3.2 was initially offered with the 915 gearbox, which had been fitted to 911s since the Carrera RS, but 1987 saw the introduction of a new gearbox, the G50.

915 versus G50 is one of the age-old IB debates. Both my cars have reconditioned 915 ‘boxes, and I delight in their use, but there is no doubt that the later transmission offers a slight improvement in shift quality. The G50 is not without its own set of issues: clutch fork problems (for example) have been addressed on some but not all cars, and G50 synchros can wear just like any other gearbox, so buyers should not choose a car based on transmission alone.

Overall condition remains the key to a successful ownership experience, and bodywork is the number one concern when buying an IB. Regardless of the relative benefits of galvanising, make no mistake: impact bumper cars definitely rust and, depending on use in early life, some G50 Carreras can often be worse than well-maintained early cars – age offers no guarantees.

911s normally rust from the inside out, so corrosion visible from above will usually be much worse underneath. Common rot spots include lower windscreen corners, front wings, front pan (floor panel in front of fuel tank), inner wings (both along the upper edge and where the bumper mounts affix to the outside of the panel) and lower front floor corners. Other areas include the rear parcel shelf, rear seat bases, rear inner wings and lower rear corners in the rear quarters, where they meet the lower valance side panels.

The most common corrosion is found in the B-posts: the slam panels just behind the doors. B-post rot is not cheap to repair, particularly when it has spread to the sills. Advanced rust here often spells rot in almost every other spot previously mentioned, so any bubbles spotted in this area should be treated with extreme caution.

Costs for body repair in the UK vary, but done properly, B-post repair with paint, including replacing the kidney bowl reinforcement behind, starts from about £900 per side. If the sills need doing at the same time, they are an additional cost, bearing in mind that some panels are no longer available from Porsche. Genuine front wings have recently come down in price, and are now approximately £700 each, but the cost of fitting and paint, plus inevitable rust repairs to adjacent panels must be factored in also. It is not unusual to find repair bills climbing above £5k in some cases – cheap cars are frequently not cheap enough.

Shiny outsides can hide scary bills, so professional inspection by a 911 specialist must be considered mandatory. With average cars costing £8,000 and upwards, it is very rare that a proper pre-purchase inspection does not immediately save its own cost as a bare minimum.

Bodywork is not an issue on our three spotless 3.2-engined cars, even on Paul Ridgley’s 123k-mile 1986 Turbo-Look Coupe, sold in the UK as the Super Sport. The Turbo-Look 3.2s were powered by the standard drivetrain, but used the body, brakes and suspension of the 930. I admit to preferring my Turbo bodies with their boost intact, but there is no denying that Paul’s Marine Blue Coupe is a beautiful example. Driving the widebody proves it to be a similar beast to little brother, though the increased track and weight does negate some of the narrow-body’s nimbleness.

The 911 received quite a few alterations for the 1986 model year, most noticeably in ventilation. Cabin ventilation was never a 911 strong point, but the bigger dash vents introduced in 1986 make a big difference to airflow through the car. Other modifications for ‘86 included lower seat rails, and bigger torsion and anti-roll bars for the Carreras: all well worth having. These were not the only changes for 1986.

Originally offered as part of Porsche’s Special Wishes programme, the Slant-Nose 911 Turbo SE arrived on the official price list in the same year. C697 VDL was delivered directly to Porsche UK, where it was registered with the famous 911 HUL press demonstrator plate. Steve Cropley of Car magazine was one of the first people to drive it, promptly composing one of the greatest motoring articles of all time. As if to demonstrate how pivotal this piece was to Porsche consciousness, four anoraks (including me) quote Cropley in unison: “Into the red in second, the speedo reads 95”.

The original 1975 911 Turbo, with its 260bhp 3.0 engine, was not much faster than the normally aspirated Carrera of the time, but development was swift, and Porsche successfully mined the car’s immense potential over the life of the model. In 1978, engine size was increased to 3.3 litres and an intercooler was added, which raised power to 300bhp. In 1986, the Turbo was fitted with Bosch Motronic, as used in the 3.2. Peak torque was now 431Nm at 4,000rpm, and the Turbo SE developed a whopping 330bhp.

They say you should never meet your heroes for fear of disappointment, but worshipping this motoring legend, in the comfort of its delicious Can-Can Red leather interior, is food for the soul. The Silver SE has lost none of its visual impact in 20-plus years and almost 60k miles – it remains a feast for the senses. Driving the car leads directly to a whole new world of boost-induced endorphins. Plant the throttle in first, second or third gear on this damp, leaf-strewn surface, and say goodbye to the grip ‘twixt Tarmac and tyres; the turbo’s rush rudely interrupting any communication they might have been enjoying. My time in the beautifully crafted Turbo SE is personally momentous, a realisation of treasured ambition, anticipation and excitement. It’s a joyous event that is over too soon, but I have a feeling I’ll be back.

I have never subscribed to the notion that, with the 3.2 Carreras, Porsche saved the best ‘til last, but the Carrera Club Sport is certainly one of my favourites. Introduced for the 1988 model year, the stripped-out Club Sport was an exercise in simplicity, dropping many of the performance-sapping creature comforts which the Carreras had accumulated over time, and replacing them with an unfettered driving experience, which has made these rare cars the most sought-after 3.2 Coupes ever produced. This immaculate example belongs to Alan Cordery and, despite appearances, the car is driven regularly, which after all is the whole point – why own a 911 you never use?

Driving the Club Sport is quite different to a common-or-garden Carrera of the period, but it is not in total contrast to the feel of the later cars. It is a touch faster but not hugely so, and it does sound a little louder but it is not noisy per se. What is different is that it is sharper: the driving position has more focus, the blueprinted engine revs with greater energy, and the whole car seems to pay slightly more attention to control inputs.

John Lawry is another Club Sport owner with a passion for lightness, as the second car in his garage is this immaculate Red Speedster. Only the Club Sport was lighter than the Speedster, which weighed the same as the standard Carrera Coupe. John’s beautiful soft-top arrives with the roof down, and despite a splash of rain, it stays down all day. “The plan,” explains John, “was to buy a Club Sport and a Speedster, see which one I liked the best and sell the other”. This approach has worked out brilliantly as, in just over four years of ownership, John has clocked up 17k of the Speedster’s 22k miles, with plenty more in the Club Sport, and there is no sign of either making an exit anytime soon.

As a Cabriolet owner, I am completely familiar with open-top 911s, but driving the Speedster is much more civilised than I expect, maybe because of the lowered seats and sleeker ‘screen. Whatever the reason, this may be my favourite application of the 3.2 engine yet. This almost-new car piques my curiosity more than any other, bar perhaps the Turbo SE, and I resolve to come back and learn more.

Everyone has their own idea of the ultimate 911, and for some it is our final car: Darren Edmond’s 1989 911 Turbo LE. This immaculate Slate Grey example has covered only 14k miles from new, and is breathtakingly original in every respect. As the swansong for a design icon, the Turbo LEs were privy to the full contents of the Porsche parts bin, from the 330bhp engine and G50 gearbox, to heated leather sports seats with gold-plated badges. They were stupendously expensive back in the day, and they are still not cheap. As a long-time 930 fan, Darren had to have his ultimate IB, and that passion is what these cars are all about.

Whether your ultimate IB is the simple 911S which got the ball rolling, or the superb Speedster which was one of the last examples delivered, the cars are surrounded with enthusiasts like all those present, who love them for what they are: simple, honest and fun.

When each of drivers is forced to pick a favourite, there is no clear winner, and for me, that is the real beauty of these cars. Whatever IB you choose to enjoy, it’s a piece of Porsche heritage that helped to keep the 911 alive. That’s reason enough for anyone to want one.

Thanks to:

Neil Thackray

Peter and Litte Andrews

Jack Wilson

Marcus Dullea

Paul Ridgley

Alan Cordery

John Lawry

Neil Dickens

Darren Edmonds

Andy Perks

Guy Wood and Chris Davenport from the PCGB

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