1981 Alpina B7 S Turbo E12 vs. 1984 B7 Turbo E28 and 1991 B10 Bi-Turbo E34

As Alpina builds its last BMW 5 Series remix, we sample three of Buchloe’s legendary turbocharged autobahn annihilators.

Words NATHAN CHADWICK

Photography ALPINA/ROMAN RÄTZKE

Turning up the boost at Zandvoort with Alpina’s ballistic bunch of 5s

Five Alive Three generations of Alpina turbo 5 Series, from B7 to mighty B10 Bi-Turbo

Turning up the boost at Zandvoort with Alpina’s ballistic bunch of 5s

All good things come to an end, they say. For decades, family-run Alpina has applied its own stardust on BMW base materials to craft cars that blend BMW M-style dynamism with luxury and refinement levels akin to a Bentley, all in the name of high-speed comfort and efficiency. Sadly, from 2026 it will be all over. BMW’s base machines will be going electric-only, which in the eyes of the Bovensiepen family is an evolution too far for their ethos. In March 2023 BMW acquired the brand, and from the end of 2025 will develop Alpina-badged cars in-house – positioning them as luxury offerings to sit below Rolls-Royces – while the Buchloe originators will move on as Alpina Classic, supporting its heritage.

Alpina recently produced its last 5 Series-based creation, the limited-to-250, all-sold-out B5 GT. To celebrate, it brought along a selection of historic turbocharged autobahn stormers in 5 Series form to the Zandvoort circuit – and as legacies go, these three are mighty. But which one gives the greatest adrenalin boost – E12 B7S Turbo, E28 B7 Turbo, or E34 B10 Bi-Turbo? Before the B7S Turbo, Alpina already had form when it came to turbocharging the E12. The original B7 Turbo was the fastest four-door car in the world when it was unveiled in 1978.

Though the car was based on the 528i, it used the 3.0-litre M30B30 engine reserved for North America and South Africa – and then Alpina proceeded to change pretty much everything about it. As would become commonplace, the crushing surfaces of the pistons were reprofiled by Mahle to be flat with the standard combustion chambers turned out and smoothed to suit, and a 264-degree BMW camshaft fitted. Oh, and one more detail – a whopping great KKK K27 turbocharger with an adjustable boost function was added.

Then in November 1981, with the forthcoming E28 version of the 5 Series around the corner, Alpina unleashed a limited run of 60 B7 S Turbo models like the one you see here, now with bored-out 3.5-litre engines and a maximum boost pressure of 0.9 bar to give 330bhp and 365lb ft of torque. To put that in perspective, that’s about the same as a BMW 1M, a car 19 years younger.

Though Alpina enthusiasts like to think of their performance saloons as being the understated alternative to BMW’s M offerings, there are ample clues that this is something special. There’s a deeper chin spoiler, a gold decal set and the words B7 S Turbo plastered in a slightly incongruous-looking Seventies-style font on the rear flanks. It also rides on 16in multi-spoke alloy wheels that might seem tiny through the prism of today’s engorged SUV ‘rims’, but must have seemed huge at the time. There’s a similar lack of subtlety when you step inside. While Alpina retained the tasteful wood panelling from the base car and added its own tree-derived gearknob, the heavily bolstered, figure-hugging cloth seats feature blue and lime green stripes.

Alpina also ditched much of the standard instrumentation for its own, with red-tipped needles for the binnacles, and added gauges for turbo boost level, oil pressure and oil temperature, before rounding it off with a leather-trimmed quad-spoked steering wheel offering just the right level of thickness. The best bit, however, lies between the front seats. The boost controller can dish out between 0.5bar and 0.9bar, to allow it to be turned down to mitigate the effects of poor-quality fuel found in parts of the continent on the engine’s performance and longevity; peak horsepower goes from 296bhp up to 330bhp.

What immediately becomes clear is how much Alpina’s ethos has evolved over the years compared to the high-speed luxury cruisers of today – this is every inch the honed performance special. The clutch pedal is heavy, and the Getrag dogleg manual gearbox – which Alpina adapted with its own transmission bellhousing, gearbox crossmember and mountings – is a suitably racey layout. The B7 S Turbo also has stiffer Bilstein dampers and big ventilated discs – this car is far from soft. It becomes immediately clear after only a few sharp corners; Alpina’s tweaks allow me to lean more heavily on the chassis than you’d ever dream of in a normal BMW of the era. However, it’s all about the engine – and its turbocharger. Of course, there’s lag, and when the torque comes it’s in one, super-sized lump. But boy, is it thrilling – there’s the familiar straight-six shimmer before a breathy rush as the turbo spins, and it’s as if you’ve sat on life’s fast forward button. It’s still quick even by today’s standards, in-gear acceleration italicising your organs with each gasp from the KKK turbocharger.

Alpina only built 60 examples of the B7 S Turbo and 149 of the B7 Turbo in E12 form, and they rarely appear on the open market. When they do, price largely depends on location and whether they’re approved for use in the USA, which has really latched onto performance German cars over the past few years.

TECHNICAL DATA 1981 Alpina B7 S Turbo (E12)

Engine 3453cc inline six-cylinder, sohc, KKK K27 turbocharger, Pierburg fuel injectionMax Power 330bhp @ 5800rpmMax Torque 365lb ft @ 3000rpmTransmission Five-speed manual, rear-wheel drive, limited-slip differentialSteering Recirculating ballSuspension Front: independent, MacPherson struts, lower lateral links, compliance struts, coil springs, Bilstein gas dampers, anti-roll bar. Rear: independent, semi-trailing arms, coil springs, Bilstein gas dampers, anti-roll bar.Brakes Vented discs front and rearPerformance Top speed: 162mphAcceleration 0-60mph: 5.9secWeight 1485kg (2273lb)Fuel consumption 22mpgCost new 75,000DM (approx. £16,500)Prices £46,000-£135,000

‘Oh, and one more detail – a whopping great KKK 27 turbocharger was added with adjustable boost’

Less chin spoiler, more Schnell spoiler. Chunky wheel, extra gauges and sports seats by Alpina. 330 turbocharged horses in 1981. Who needs a 911 Turbo?

In 2019 an Alpina E12 would cost around £35k, but nowadays you’d probably need to put a 1 before the 3.

As the pinnacle of the early Alpina 5s, this is a great reflection of the firm’s period status as E9 CSL touring-car preparers at the weekend, road-car remixers by weekday. However, unlike most motor sport-tuned motors, this one won’t leave you reaching for your osteopath’s number…

The introduction of the E28 5 Series marked a step forward for BMW – not only was it the first car designed with the aid of a computer (via the only one the firm had, which was usually used for payroll payments), but it was also much more luxurious, with air conditioning, ABS and a dashboard angled more towards the driver. The base materials were already more sporting, to which Alpina added a familiar set of requirements.

Alpina E28s came in two flavours, naturally aspirated 245bhp B9 or 261bhp B10 3.5 form, or B7 Turbo. All versions used the 3.5-litre M30B34 straight six that, at the time, was reserved for the top-of-the-non-M-range 635CSi E24 and 735i E32. As standard, this provided 218bhp, but in B7 Turbo form, it was closer to 300bhp.

Alpina reprogrammed the Motronic fuel injection, incorporated the E23 745i cylinder head, crafted a bespoke exhaust manifold, fitted the same KKK K27 turbocharger from the E12 and used lighter, flat Mahle pistons with crushing surfaces, adapting the combustion chamber accordingly. Alpina had purposefully chosen to keep the power output lower than 300bhp to leave headroom for the 330bhp version used in the pricier 6 Series-based B7 S Turbo, and restricted boost to 0.7bar.

Stepping inside, it’s immediately less renegade racer, with a discreet blue-and-green stripe on the cloth Recaro seats to relieve the very of-its-time funereal black cabin. Look closer, however, and Alpina also reworked the instruments again, though slightly more subtly. The binnacles’ grey contrasts against the black, while the standard E28 onboard computer has been replaced with a bespoke item that displays the turbo boost and oil pressure, and oil and water temperature. The boost controller remains nestled between the front seats.

Time to grab the leather-trimmed steering wheel and get busy, and the contrast to the E12 is immediate. Though the gearbox is still a dogleg Getrag five-speeder, the clutch pedal is lighter, while the steering is lighter and smoother. There’s less feedback through the rim, but considering this car’s remit – high-speed, long-distance travel – a lack of hyperactivity is welcome.

Don’t go thinking that the E28 has deadened the cornering enthusiasm. The lighter steering makes the E28 feel far more agile, zesty and somewhat less awkward. While the E12 is entertaining and engaging, it was pretty much old bones when the ultimate turbocharged S version appeared. Chassis revisions for the base E28 use dual-link front suspension from the E23 7 Series, further invigorated by Bilstein dampers fore and aft. Progressive-rate coil springs and a limited-slip differential out back further increase the sense of dynamism. It feels crisp and controlled; Alpina also upgraded the E28’s notoriously undereffective brakes with 300x30mm discs. As a result, where the M535i feels that it could bite on a moist road, the B7 Turbo provides more confidence that you won’t wake up sharing a hay bale with a somewhat startled sheep.

Once again, it’s the engine that provides the centrepiece. The natural torqueyness of the M30B34 engine before the turbo kicks in means there’s enough off-boost pull to be quick enough in most places. And when that turbo does let fly, it’s perhaps a little less dramatic than the E12, but there’s no doubting its urgency. The gearchange is on the long side, but it’s still slick, allowing you to serve up another ratio’s worth of sternum-pinning excess.

The E28 B7 Turbo isn’t as rare – discounting the more powerful Japanese version – as the E12, with 236 cars built between 1984 and 1987. A further 42 B7 Turbo Kat versions were built with a catalytic converter between August and December 1987. They still don’t come up for sale very often; the last one sold publicly made around £45,000 in 2019 but there’s been a renewed interest in Alpina since.

The E28 B7 Turbo shows the further refining of the Alpina brand, as its relationship with BMW became better defined. As BMW’s M department adopted a more distinct part of the brand halo, Alpina’s more measured approach to performance stood apart. Though our test car does without the four-speed ZF auto fitted to many non-Turbo Alpina E28s of the era, the first hints of what the brand would ultimately become are clear to see.

The late, great veteran journalist and racing driver Paul Frère once described the B10 Bi-Turbo as ‘the best four-door in the world’. It was certainly the fastest in the world, and out-dragged a Ferrari Testarossa to 60mph. It was also the most extensively reworked car Alpina had ever created, at a development cost of £1.6m in 1989 – approximately £3.5m today.

What started life as a 211bhp M30B34 engine from the 535i retained only the cylinder block, crankshaft and basic cylinder head design. Alpina fitted lighter, forged Mahle pistons for a lower compression ratio of 7.2:1, plus stronger conrods with bespoke drilled main bearing housings featuring pressure valves to spray oil on the underside of the pistons to keep them cool. It also revised the cylinder head with a reprofiled camshaft, and replaced the 46mm inlet and 38mm outlet valves with 47mm BMW parts and bespoke 38mm items respectively. The combustion chambers were turned out and smoothed, and the outlet and inlet ducts machined.

Engineers chose chose a twin-turbo setup in a bid to reduce lag, the Garrett T25s feeding a bank of three cylinders apiece.

TECHNICAL DATA 1984 Alpina B7 Turbo (E28)

Engine 3430cc inline six-cylinder, sohc, KKK K27 turbocharger, Bosch Motronic M1.2 electronic fuel injectionPower and torque 296bhp-316bhp @ 5400rpm; 375lb ft @ 3000rpmTransmission Five-speed manual, rear-wheel drive, limited-slip differential Steering Power-assisted recirculating ballSuspension Front: independent, MacPherson struts, lower lateral links, compliance struts, coil springs, Bilstein gas dampers, anti-roll bar. Rear: independent, semi-trailing arms, coil springs, Bilstein gas dampers, anti-roll bar.Brakes Servo-assisted vented discs front and rear, ABSPerformance Top speed: 165mphAcceleration 0-60mph: 6.2secWeight 1400kg (3086lb)Fuel consumption 23mpgCost new £75,000 (est) 1985Classic Cars Price Guide £80,000-£130,000

Alpina subtly reworked the gauge binnacle M30 engine’s underlying torque evident.

‘Alpina’s E28 B7 Turbo shows the further refining of the brand’

There’s an intercooler at the front of the water radiator, and adjustable boost – between 0.4 and 0.8bar, this time from a dial next to the driver’s knee.

While 360bhp is big power, it’s the torque that’s truly eyeopening. Fitting two smaller turbochargers means there isn’t quite the same wait for theatrics you’d get for the earlier cars, but with a far-off whoosh and shimmering rasp from the straight six, instantly you’re looking for the next dialling code for whichever of bit of continental Europe you appear to have teleported to. It has more torque than a Testarossa, Aston Martin Virage or Porsche 928 GT, yet you have room for four passengers, including their legs (looking at you, 928 and Virage).

Alpina found such reserves of bitumen-churning heave destroyed the standard BMW drivetrain, so had a bespoke propshaft made, and asked Getrag to build a H-pattern fivespeed to cope. There’s also an oil-cooled limited-slip differential, thicker anti-roll bars and new dampers – Bilsteins up front and Fichtel & Sachs self-levelling items out back. This is no mere tuner special – BMW was so impressed with the outcome it reserved the last 50 M30 engine blocks built for Alpina to use. It looks the part too, with a deep chin spoiler, 17in alloys wheels and a decal set. It’s perhaps more subtle than the E28, but those fellow road users that know, will know…

It was twice the price of an E34 M5 when new; it feels twice the car. There’s a weightiness to the suspension, the clutch is heftier and the gearbox a little notchier than perhaps I’d like, but shepherding this volume of torque in 1989 took heavy engineering, and compared to some big-torque beasts of the same era it’s positive across the gate.

It weighs much more than its forebears, but this hasn’t translated into a Teutonic take on a straight-line muscle car. There’s not much feel, but you have to really be testing your mortality for the nose to trail wide. Get too aggressive and its early traction control system, Automatic Stability Control, will cut power – but you can turn this off if you’re feeling flamboyant. I’ve driven all these cars over the years and the B10 Bi-Turbo is the one that feels most constrained by UK laws. Change down from fifth to fourth at, say, 60-70mph and the engine’s barely come on cam, let alone firing the turbos. That should give you an idea of the performance potential…

Alpina built more than 500 B10 Bi-Turbos over five years, and on the continent you’ll be paying between €60,000 and €100,000 for one. Though it’s believed just one was sold in the UK when new, around a dozen are believed to have been imported since. A 117k-mile example sold at auction in late 2022 for £40,500.

The Alpina B10 Bi-Turbo, like the most endearing cars, has a few flaws but it makes up for them with its all-conquering personality. It makes the E34 M5 seem pedestrian. In fact, fully lit, it’ll pretty much toast most things of its era – and certainly give anything newer a fright.

All three Alpinas offer something rather more than their M-based counterparts, but each has its own feel, neatly underlining the evolution of Alpina’s purpose over the years.

The E12, unsurprisingly, feels more closely aligned with outright performance rather than comfort. After all, it was Alpina that gave BMW its first European touring car championship success, and has been a quiet collaborator with BMW M on motor sport projects ever since. It’s a far more physical car than those that followed, but ultimately more rewarding.

The E28 might have lacked the same punch as its predecessor, but shows the clear path Alpina perhaps needed to take compared to the emergent M road car operation. Despite being more comfy and easier to operate, it’s no less engaging, serving up its boost-heavy theatrics in a more accessible manner. Ultimately, it’s the B10 Bi-Turbo that provides the most satisfying embodiment of the Alpina philosophy. It neatly blurs the line between outright performance saloon and luxury cruiser. It’s certainly the most packed with adrenalin – dropping down to third and unleashing the mighty engine boggles the mind in 2023; in 1989 this thing must have been otherworldly. The best news is that the wider market hasn’t quite picked up on the classic Alpina scene. Yes, you’ll pay a premium over an E12 M535i, or an E28 or E34 M5, but you need only look at the sums paid for AMG-fettled Mercedes-Benzes of the Eighties and Nineties to see where things could go. While we are perhaps unlikely to see $800,000 Alpinas to match what certain AMG Mercedes-Benz W124s have achieved at auction, you can expect BMW’s marketing machine to lean heavily on Buchloe’s automotive heritage when it starts producing its own line of Alpina-branded machines. The results of all that, plus increased support for its older cars from Alpina itself, may well make today’s prices seem like bargains…

Future values aside, all these cars are landmarks. All three pushed the envelope for four-door performance, bringing supercar-style acceleration and maximum speeds to new heights, shaming exotic names of Porsche, Ferrari and Aston Martin for accelerative thrust yet retaining everyday usability. Alpina itself would abandon turbocharging for naturally aspirated smoothness after the B10 Bi-Turbo, and would only come back to forced-induction petrols in the 2000s. That marks out these exquisitely engineered marvels as exotic slivers of history that, unlike their naturally aspirated successors, can comfortably go toe to toe with their M department brethren, and blow them out of the water. Forget the Ultimate Driving Machines – these are the Ultimate Continent Crushers.

TECHNICAL DATA 1991 Alpina B10 Bi-Turbo (E34)

Engine 3430cc, inline six-cylinder, sohc, two Garrett T25 turbochargers, Bosch Motronic M1.2 fuel injectionMax Power 360bhp @ 6000rpmMax Torque 382lb ft @ 4000rpmTransmission Five-speed manual, rear-wheel drive, limited-slip differentialSteering Power-assisted recirculating ballSuspension Front: independent, MacPherson struts, lower lateral links, compliance struts, coil springs, gas dampers, anti-roll bar. Rear: independent, semi-trailing arms, coil springs, Fichtel & Sachs self-levelling dampers, anti-roll barBrakes Servo-assisted vented discs front and rear, ABSPerformance Top speed: 180mphAcceleration 0-60mph: 5.2secWeight 1693kg (3733lb)Fuel consumption 25mpgCost new DM146,800 at launch (c. £100,000) 1989Classic Cars Price Guide £40,000-£60,000

Later interiors dialled the luxury up a few notches. On the far side you’ll find a pair of Garrett T25 turbos.

‘Change down from fifth to fourth gear at 70mph and the straight six has barely come on cam’

Subtle badging, with the BMW roundels retained Rotary boost dial a feature of all three cars Variable boost pressure is a welcome engineering flourish Alpina had a bespoke Getrag ’box built for the B10 Biturbo As the 5 Series developed, so did Alpina’s philosophy.

Early interiors were racier affairs than those of later models Changing instrument colours is an Alpina company calling card.

All Alpinas carry a numbered plaque inside Usually understated, but plenty of clues that it’s not a normal BMW...

‘Classics our focus for the next 25 years’

Florian Bovensiepen on the family firm’s next, classic-orientated chapter

Son of late Alpina founder Burkhard, Florian Bovensiepen now runs Alpina with his brother Andreas. He was just entering the company after finishing his studies when the B10 Biturbo was released, and is now preparing to take the company into a new chapter. ‘My father was always a freak of frugality,’ he says. ‘He always looked for the best technical option before cost, not looking to make “fake” horsepower with a lot of fuel – he was all about high performance and low consumption.’

After his father’s passing in October 2023, Florian continues to run the company alongside his brother Andreas. The new-car business is doing well – it produced around 2500 cars in 2023, double that of a few years ago. It’s a far cry from the limited-number specials of the Seventies and Eighties, though Florian’s fondest memories come from Alpina’s first big-scale project, the B10 Bi-Turbo based on the E34 5 Series. ‘We were testing the engine on the bench, and would take it to high revs – then we’d switch off the light from the testing cabin. The turbochargers and manifold would glow red like they were on fire,’ he recalls. That heat forced Alpina to invest heavily in cooling, both in the engine bay and in the rear axle, but the technical challenges didn’t stop there. ‘We had to make our own propshaft because the torque kept snapping the standard BMW one,’ he explains. Performance was so high for the time, Alpina partnered with Michelin to develop a tyre that could sustain such high speeds. ‘We spent a long time on development, with lots of testing miles – we ended up with the first use of the Michelin MMX tyre.’

The B10 Bi-Turbo is a car that Florian holds dear. ‘You need a heavy clutch thanks to the torque; it’s hard to drive, but you get great information back from the car,’ he says. ‘I did a mileage test to the other side of Germany. I was almost out of fuel and stopped at a petrol station. On the B10 Bi-Turbo there’s a second tank with 30 litres, in addition to the basic 80. I got up to 75 litres and the attendant came out, looking under the car – when I got to 95 he asked me if there was something wrong with the pump!

On that subject, the Pierburg Zenith DL mechanical fuel injection systems have been a persistent problem for classic Alpinas. The mechanicals don’t cope well with long periods of storage and require professional servicing, only possible in Buchloe and at one other specialist in Germany. ‘Ten years ago we moved to a smaller supplier, but the quality was not so good,’ he admits. ‘So we used our knowhow to rebuild parts and repair the old systems, but now we’ve developed a full digital injection system.’ The E12 we’ve driven today has been so-equipped – but we wouldn’t have known because it’s hidden in the engine compartment. Even an Alpina connoisseur would assume it ran the original Pierburg system. The fuel systems, drivetrains, axles, brakes and engine parts are to be the main focus of the Alpina Classic business – at least for now. ‘We have a long history of know-how, so we are looking to produce new “old” mechanical parts,’ Florian says. ‘We can look into bodywork when we see how the business develops.’

There are no plans for Alpina to join the resto-mod ranks, at least for now. ‘We have thought about it, and some of our guys visited Singer. Classic parts supply from Porsche is great – unlike that of BMW – and such cars have a high price. Does this work with a BMW? We’ll have to see. Our current priority is on our daily business.’ That will see the team at Buchloe being busy building its last 2500 cars in the coming year, Florian says. ‘But the classic business is our focus for the next 25 years.’