Last week, and absolutely not in Geneva, Porsche unveiled the seventh generation of 911 Turbo. With almost 650bhp, it receives the biggest hike in power of any 911 Turbo and will surely be a formidable thing to drive, as I hope to be able to confirm quite shortly, coronavirus willing. In the meantime, I thought it might be mildly diverting to look back at where it all started.
However great had been the 911 through the ‘60s and early ‘70s, no one thought it comparable to the knee-tremblingly beautiful Italian supercars of the era with their mighty twelve cylinder engines. And then came 1974.
If you want irrefutable proof that racing improves the breed, look at the very first 911 Turbo, as presented in production form at the 1974 Paris motor show. It had been made possible by Porsche’s decision to go Can-Am racing with the 917 in 1972 and realising its 5.0-litre engine needed a little boost to be competitive against the over 8.0-litre Chevys wielded by the opposition. That boost was provided by the turbocharger.
So having mastered at least to some extent that peculiarly dark art in a racing context and with a desire to push the 911 upmarket in both positioning and price, a turbo 911 seemed an obvious step. It even had a new name: 930.
But development was not easy. In the road car arena turbos were not so much in their infancy as barely out of the birth canal. BMW had beaten Porsche to the showroom with its hilariously lag-prone and less than reliable 2002 Turbo, but it had not been a commercial success, nor had the first ever turbocharged road car, the 1962 Oldsmobile Jetfire.
Initially the 930 Turbo engine was to be based on the 2.7-litre unit, but tests showed the 3.0-litre engine from the Carrera was preferable, more for its better behaviour off-boost and reduced lag than its extra power. It was installed in the already crowded engine bay of the 911, its KKK turbo blowing at around 0.8bar to boost power to 260bhp. It could have had more, but Porsche limited its output primarily not to scare its customers.
Unlike almost every other 911, it ran through a gearbox with just four speeds. At the time the reason given was that the Turbo had so much torque it didn’t need any more gears. A perhaps more accurate interpretation is the Turbo had so much torque it needed commensurately beefed up gears and there wasn’t thereafter room in the casing for five.
Its suspension was new too, following approximately the old architecture but changed not just in spring, roll bar and shock absorber rates, but quite fundamentally in its actual geometry, though this was done as much with homologating race versions in mind as anything else.
Visually there was not much to tell between a Turbo and a Carrera of a similar vintage: the swollen wheel arch blisters at both ends were a giveaway, as was the rear spoiler design, but as the car was so dramatically different beneath the skin, Porsche chose to let its performance do the talking instead.
It was received with a blend of euphoria and fear. My antecedents could barely believe its punch, but there’s hardly a review to be read that does not issue stark warnings of the consequences of playing fast and loose with so much power. Seems odd now, what with even the most basic Boxster besting its output.
But in fact Porsche was not yet done with the Turbo. If the 1974 Turbo was an exploratory toe dip into fresh waters, the 1978 car was a knees-up bomb off the top board. By expanding both the bore and stroke, Porsche took the engine up to 3.3-litres and, critically, used another racing lesson and fitted it with an air to air intercooler, capable of dropping the charge temperature of incoming air by a colossal 50 degrees centigrade. Cooler air is denser air, denser air has more oxygen in it, more oxygen makes a bigger bang when ignited with fuel and more power results.
As a result Porsche was actually able to peg back maximum boost pressure a tad, raise the compression ratio from 6.5:1 to 7.0:1 to reduce lag and still produce a big, fat 300bhp – a number no road Porsche had ever even approached, even though it’s still less than half the output of the latest Turbo.
To drive even the later 3.3-litre cars take some learning. They are quite contradictory cars too: although by far the fastest 911 seen up until that time, a Turbo was also easily the most refined. The motor is still pretty savage on boost, entirely hopeless off it. You have to be patient with it both in a straight line waiting for the magic 3,500rpm to appear on the large central tachometer which is where the boost gauge flicks hard right, and also in the corners.
If the mantra to driving any old 911 is ‘slow in, fast out’, the way to drive an early Turbo is ‘even slower in, even faster out.’ You really don’t want to be arriving too fast at a corner because if you need to slow, it really will be pretty merciless with you; but so long as you’re conservative on entry and anticipate just how long it will take the boost to build before the apex, you can use the enormous traction from its widened rear track to achieve exit speeds unlike any previous prior 911.
Those early Turbos are interesting cars, but spoiled to an extent by those four speeds having to cover a speed range from rest to over 160mph combined with a proper powerband of no more than 2,500rpm. You had to use first gear as a full time ratio and some of them had more cooperative gearboxes than others. Right at the end of production in 1989, Porsche did slot its new G50 five speed gearbox into the 930 Turbo and that pretty much transformed the car. But those machines are exceptionally rare and expensive. A quick trawl around the classifieds found one for sale, listing at £120,000 even in these straitened times. And they’re good, but not that good.
Thank Frankel it's Friday
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