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Porsche 924 Carrera GT and 928S – The transaxle twins

Porsche 924 Carrera GT and 928S – The transaxle twins Classic and Performance Car

Porsche’s 924 Carrera GT and 928S were born of the same ethos yet couldn’t be more different. Glen Waddington compares

These cars are separated by three years, four cylinders and 90bhp. One was bred for racing, the other as a refined GT. One was even going to be an Audi, for goodness’ sake. Oh, and one is worth around three times as much as the other (more power and cylinders cost much less than this extreme example of the might-have-been Audi).
Yet they’re united by a common engineering ethos. They both transmit power to their rear wheels via a rear-mounted gearbox. A transaxle. And that’s something they share with the fabled 911, even if their engines are water-cooled and mounted up-front. Not a real Porsche? Pah.
In the words of Ferry Porsche himself, quoted in 1969: ‘It is not important whether our automobiles are cooled by air or cooled by water. What is important is to do them well.’ As for the front-mounted engine, the company would achieve near-ideal weight distribution by applying knowledge gained by Ferdinand Porsche in his designs for the pre-war Mercedes Silver Arrows racing cars.
The gearbox would be mounted in unit with the differential between the driven rear wheels, connected to the engine by a backbone tube inside which runs the propeller shaft, held in place by four bearings and two rubber-bushed mounts. In the case of manual cars, the gearlever is mounted directly on the tube, to reduce the flex often inherent in such a long linkage. A case of ‘doing it well’.
The two separate development stories I’ll try to keep brief. Porsche and VW had jointly marketed the 914, Porsche’s mid-engined, flat-four-powered junior partner to the 911, but in 1974 that joint venture came undone as VW looked towards the profits from the Golf (and its more sporting stablemate, the Scirocco) to rescue it from the brink. The last 914s faded away from the Karmann production line in 1976 and the 911 could easily have ended up as Porsche’s sole product line at a time when noise, emissions and crash regulations might have rendered it unsaleable.

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All those aspects, however, were being addressed by a new front-engined, water-cooled luxury coupé to sit above the 911, and – possibly – even replace it. That car became the 928, launched in 1978, of which more shortly. But what about a replacement for the more affordable 914?
Well, in 1972 Volkswagen had commissioned Porsche to develop a four-cylinder, front-engined flagship coupé that would go into production badged as an Audi. Such was the plan, anyway. In the event, VW reneged on its agreement when the joint marketing programme came to an end. Tooling was already being prepared and testing was in progress, yet VW was convinced that the Scirocco was the only sporting coupé it would need. So Porsche bought back the rights to the project and put it into production (in Audi’s factory at Neckarsulm) as the 924 for 1976. 

Porsche 924 Carrera GT and 928S – The transaxle twins
Despite the breakdown of the relationship between Porsche and VW, this was still a car designed by Porsche using parts from around the VW empire – just as had been the original 356 of 1948 – and it would be built as such. In this case the rear-mounted transaxle was a front-drive Audi 100 gearbox complete with its bellhousing, another identical bellhousing covering the engine’s flywheel in the usual way and the engine-speed propshaft running between them. Front suspension was Golf-based, with struts and coils plus stronger lower wishbones from the Scirocco. Semi-trailing arm and torsion bar rear suspension followed 911 practice, but the parts came from the Beetle in its most sophisticated guise. The rack-and-pinion steering was VW-sourced too, as were the disc/drum brakes, which came from the NSU-designed K70 saloon.
The overhead-camshaft four-cylinder engine, long criticised as being VW van-based, was originally designed for the Audi 100 executive saloon (although it did find its way into the LT commercial range, as well as AMC’s Gremlin in the States). With an exclusive, handbuilt, Porsche-designed cylinder head and boosted by fuel injection, it was good for 125bhp. That was plenty for a car weighing only 1080kg, especially one designed with a nod to aerodynamics (Cd 0.36) by Porsche’s own Harm Lagaay – his first work for Porsche, on which topic it has been said the 924 ‘looks like how a Dutchman imagines an Italian sports car’! – and Anatole Lapine. ‘A design is right only if it remains good for years,’ Lapine has said. The 924 was certainly going to put that theory to the test.
Lapine was in charge of the 928’s styling too, but while development of that car began in 1971, it was halted (in light of the oil crisis) so Porsche could concentrate on the 924, before being revived in 1974. VW had offered its new five-cylinder technology, which was considered too heavy for the 924 but could have become the basis of a V10 for the bigger car. Power, though, came instead from a brand new V8, initially of 4.5 litres, designed by Porsche. Half of it would later become the power source of the 944, but that’s another story.
Nor were any VW bits visible elsewhere. While the 924 proudly displayed Golf door handles, Audi heater controls and more, the upmarket 928 was properly bespoke. What both transaxle cars did share was a similar silhouette, intended to evoke that of the 911 with its long, sloping tail, and both featured pop-up headlamps, a low snout and minimal front air intakes, so the driver would enjoy an unimpeded forward view – just like in the 911.
The two cars we have here are not the earliest of their respective types. Instead they are largely regarded as the best. The 928S (this one is from 1983) displays the unadorned purity of the early 928 shape, though with the 300bhp 4.7-litre V8 and other detail improvements that make it a much better car. Sure, there’s yet more power and luxury in a late-1980s S4, and the more bombastic GT and GTS are becoming the most prized, but this car defines the original intent of the 928.
The 924, on the other hand, is represented here by a 1980 Carrera GT, the most sought-after 924 of all because it is basically a a homologation special, one of only 406 made, and is fitted with a 210bhp turbocharged version of that otherwise conventional Audi 100 engine. Derek Bell was given one when he was a works Porsche driver and has told some that he will never, ever part with it. Enough said, really.
At the heart of that juxtaposition between the fiery racer and the luxury GT is a five-speed manual gearbox, with first down to the left on a dog-leg. Mounted at the rear, of course. Yes, these two cars, so different in approach and character, share identical transmission engineering.

Porsche 924 Carrera GT and 928S – The transaxle twins
But while a lightweight, powerful, race-honed coupé is Porsche’s heartland, even if the car in question has a front-mounted water-cooled engine, the luxurious 928 was very much unbroken ground. ‘It was aimed at different people,’ 1977 Le Mans winner (in a Porsche 936) Jürgen Barth tells me at Porsche’s museum in Zuffenhausen, outside which our two cars are parked. ‘Porsche’s MD Peter Schutz called them “high achievers”, a self-employed elite who liked to drive themselves.’
And what about the ‘people’s Porsche’, that original 924 in its basic form? ‘The suspension was good, really good. All VW parts and it worked so well. But those drum brakes at the rear… they gave us nightmares! Rear disc brakes came along very soon.’
There are disc brakes all-round on this gloriously red 924 Carrera GT. Snuggle into its 911-sourced highback tombstone seats, careful to squeeze your thighs beneath the low-set wheel, and survey a sombre dashboard layout that makes up in conciseness and finish what it lacks in excitement. This is a businesslike interior.
The four-cylinder fires up with a somewhat belligerent and uncouth roar. Van-like? Well, it’s no Ferrari V8, but a foray on the loud pedal reveals strength in depth. Once you’ve got past the massive turbo lag, anyway. There’s 210bhp on tap here, no small output for a 2.0-litre road car of 1980 vintage, and its forced induction feels exactly that. Like the interior, the engine is businesslike rather than charming. Its soundtrack is no serenade.
No, leave all thoughts of imminent seduction to the handling. This is what the 924 is about. It dances along a winding road, feeling light and agile yet planted and unthreatening. There are four turns between locks for the unassisted steering, but that’s because the turning circle is tight; you don’t feel as though you’re winding on endless armfuls. The tail is involved in every corner yet, while that transaxle is there to add its weight, you don’t ever experience the unsettling pendulum effect that comes with 911 territory. Put simply, this car can make you feel heroic.

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As can the 928, yet in a totally different way. Those high-achievers? Get yourself on the autobahn and feel how the 928 rules with total authority. This car is all about travelling at high speed. On a derestricted section of tarmac you can simply wind up through those five long gears, hearing the V8 build from a soft burble to a cultured snarl, its tone absolutely rock-steady as you reel in the miles.
The power steering inspires huge confidence when curves rear up and surprise you, the brakes haul you back like a jet-plane’s reverse thrust, and the dashboard’s well-considered ergonomics leave you to enjoy the embrace of the supportive seat, so you can concentrate on the drive rather than hunting for how to notch back the air-con by another degree. We’ll ignore the colour-coded burgundy trim for now.
Great cars, both, in totally different ways. You’d certainly find room for one of each, given the opportunity. Anything about them that causes consternation? Well, truth be told, that damned transaxle. Great for weight distribution, less good for shift action. It’s weighty in both cars, and demands concentration if you’re to grab a clean change. Nothing new there for any pre-Noughties Porsche, to be fair, but it perhaps explains why more 928s were built as automatics than manuals, and why the transaxle Porsches are, it turns out, great cars in spite of that rear-mounted gearbox as much as because of it.
All of which utterly makes sense in Porsche world – the only place it could. After all, who’d design a car as wilfully unconventional as the rear-engined 911? The compromises that car has forced on the unwary certainly never held it back.
Words: Glen Waddington // Images: Antony Fraser

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