Supercharged 500bhp 2005 Alpina B5 E60

Alpina’s B5 was the only factory-produced supercharged 5 Series E60 and made a glorious alternative to the ubiquitous M5 E60.

Words: Bob Harper

Photos: Jason Dodd

LUXURY AND PACE

Super Five

We take a look at the subtle super saloon, the superb supercharged 500bhp E60 Alpina B5

Super saloon. Two words that should get the automotive juices of every petrolhead flowing. From the Lotus Carlton to untold AMGs, the debate will rage over which is, or was, the best and undoubtedly, the one name that will crop up time and again is the BMW M5. For nighon 40 years, the M-powered 5 Series has been the car to beat, but for those of us who might prefer something a little bit more distinctive, something with a smidgen of je ne sais quoi, there’s another name to throw into the melting pot: Alpina.

Based just down the road from BMW’s Munich HQ in the small town of Buchloe, Alpina has been fettling fast Fives for even longer than BMW. When BMW was just getting around to shoehorning its biggest engine into the E12 5 Series to create the first M-badged saloon, Alpina had already been producing a 300hp turbocharged monster for a couple of years. When the first M5 appeared in the E28 shell, Alpina had its more powerful B7 Turbo models, and in the E34 body, Alpina’s B10 Bi-Turbo was an even more potent confection than BMW’s M5.

However, while these early fast Fives from Alpina might have eclipsed the M division for outright power, it was their chassis prowess that raised eyebrows. They set the stage for Alpina’s now legendary ability to make a car ride well and handle with a suppleness to their road manners that made them a far better bet as an everyday machine. Perhaps they didn’t quite have the scalpelsharp turn-in of an M car, but the breadth and depth of their abilities became legendary.

When it came to the fourth generation of Alpina-fettled 5 Series, the company made a major departure from the models that had come before it. Previous generations had employed the same basic engine configuration as the equivalent BMW M car, but for the E60 5 Series, BMW was desperate to link its F1 program to its road cars and opted for the bonkers S85 to power its M5. Fine engine though it was, it wasn’t really the sort of thing that would be suitable for an Alpina, so while the M5 went down the high-revving V10 route, Alpina opted for the charms of a V8.

The company had already worked its magic on the 7 Series to create the B7, and thus, it was prudent to use the same engine in what would become known as the B5. The engine was a thoroughly reworked version of the Valvetronic 4398cc V8 that could be found in the 545i, and it’s safe to say that there was considerably more to it than just slapping on a blower for the extra oomph. The H1 engine, as Alpina called the B5’s powerplant, consisted of more than 1200 parts, a third of which were produced by BMW, a third were made by BMW suppliers to Alpina’s specification, and the last third were modified or produced by Alpina.

Blocks and cranks were made by Steyr to Alpina’s specification, while the Mahle pistons were also bespoke. A centrifugal supercharger was fitted, delivering 0.8 bar of boost, with air being directed via a simply huge intercooler to the combustion chamber. There was a clever additional throttle switch that ensured at low rpm the engine behaved like a naturally aspirated unit, with the compressor simply spinning fast enough to ensure it could spool up incredibly quickly when a boot full of throttle demanded more power. Vital stats were suitably impressive, with 500hp at 5550rpm and 516lb ft of torque peaking at 4250rpm. It’s worth noting that 80% of that torque was available from just 2000rpm, and if you remember the old adage that power is how fast an engine can punch and torque is how hard it can punch, you’d conclude the H1 in the B5 was an absolute sledgehammer. As with all Alpinas, there was far more to the B5 than a ‘simple’ engine upgrade, and that started with the transmission. The gearbox itself was a standard BMW ZF 6HP26 unit, but due to the most un-BMW-like power output of the engine, it was modified by Alpina. First, second and third gears were strengthened, and it had different filtering and temperature and pressure values.

Alpina’s trademark Switch- Tronic gearchange buttons were affixed to the rear of the steering wheel in the three- and nine-o’clock positions. Alpina experimented with a limitedslip differential but, in the end, decided to fit a conventional BMW diff – from a 745d, the strongest one in BMW’s parts bin – and recalibrated the DSC set-up instead. This was tuned to intervene if one wheel lost traction suddenly but to be less intrusive if both wheels started to slip more uniformly.

The basic suspension geometry was unaltered, but both the springs and dampers were built to Alpina’s specification, and this led to a wonderfully supple ride, with ample grip thanks to the bespoke Michelin rubber that was developed for the B5. Stopping the B5 was left up to standard BMW discs and pads, but not the ones you’d find on the rest of the 5 Series range. Alpina again raided the BMW parts warehouse and opted for the discs and pads that would normally be seen on a Middle Eastern spec 760Li, the heaviest car in the range, and they made light work of washing off speed on the B5 without the typical grumbling that could affect the M5’s drilled rotors.

Externally, there were the usual Alpina embellishments – a deep front apron, rear spoiler and a set of M5 sills – while the traditional pinstripes were optional. Inside, you could go as wild or as mild as your wallet and taste decreed with a range of bespoke Alpina leathers, logos, wood finishes and additional BMW equipment. Most were finished in relatively subtle and classy hues, but we have seen one or two interiors where sunglasses were a must.

To drive the B5 was, for the most part, an absolutely sublime machine. On first acquaintance, it’s almost impossible to get past the engine as it’s both gloriously melodic and absurdly powerful. Comparisons with the M5 are inevitable – they’re both 500hp super saloons after all – but the way the B5 goes about its business is so different from the manic M. In the M5, you need to have all the switches in the right position: fastest gear change mode, plenty of revs dialled in, engine in P500 S mode… in the B5, you just need to introduce your shoe to the carpet, and off it flies. Its straight-line performance is simply phenomenal and accompanied by a glorious V8 soundtrack – loud enough to hear properly but never intrusive. It might lack the banshee 8000rpm wail of an M5, but it’s still superb.

The B5’s interior was suitably opulent, and there were virtually countless options available when it came to adding your personal touch.

Back when the B5 was new, it was pretty much the case that the Alpina was the best-riding 5 Series model bar none – perhaps a 520d on 16s was just as supple – but the way the B5 soaked up imperfections despite its 19” rims was nothing short of eye-opening. The flip side of the coin is that the B5 isn’t quite as scalpel-sharp when attacking a challenging back road as an M5. During quick direction changes, the Alpina feels less surefooted, and if you try to use all of the B5’s performance on a bumpy section of road, you’ll see the DSC telltale light almost permanently on as it struggles a little to deploy all 500hp. Switch the DSC off, and the B5 is capable of vaporising its rear tyres in a matter of seconds, especially as the less-loaded rear tyre tends to spin up far too easily, especially when coming out of tighter corners. Driven at eight or nine 10ths and the B5 is glorious, but trying to extract that last bit of pace can lead to frustration that it’s not quite as composed as it could be.

But for the other 99% of your driving time, it’s simply sublime. The slightly wayward on-limit behaviour was taken care of by the B5’s LCI changes when, along with BMW’s cosmetic upgrades, the B5 morphed into the B5 S. That meant more power and torque – now 530hp and 535lb ft – but, more importantly, recalibrated suspension settings, now with just two modes, Sport and Comfort, and the appearance of an LSD on the options list. That latter item would cost an additional £2500 but was well worth the additional outlay if you wanted to extract the best from your B5 S.

In this latter guise, the Alpina Five really was glorious, offering more poise when pushing on, and while you could still feel the rear tyres being thoroughly put through their paces by all that torque, it felt far more controlled than it did before. It didn’t make the B5 S a huge seller, though, and at over £70k when equipped with the LSD, it was still a hard sell. The first generation of B5 found 71 owners in the UK, with the S garnering just 12 sales… add a smattering of Tourings to those figures, and you get a total of fewer than 100 B5s for the British market, making them a far more exclusive proposition than an M5.

And for 95 % of the time, we reckon it was the better car too. It was subtler than an M5 yet could show one a clean pair of heels in most circumstances, and, all the while, retaining a level of ride comfort an M5 could only dream of. In extremis, the B5 wasn’t as poised, but overall the B5 was most definitely greater than the sum of its parts and should go down in the annals of history as one of the very best super saloons.

the B5 was most definitely greater than the sum of its parts and should go down in the annals of history as one of the very best super saloons

Despite the 19” Classic alloys, the B5’s ride was incredibly supple

The engine was a thoroughly reworked version of the Valvetronic 4398cc V8 that could be found in the 545i, and it’s safe to say that there was considerably more to it than just slapping on a blower for the extra oomph.

TECHNICAL DATA FILE E60 Alpina B5

• ENGINE: 4.4-litre supercharged V8 H1 BMW N62B44
• MAX POWER: 500hp @ 5500rpm
• MAX TORQUE: 516lb ft @ 4250rpm
• 0-62MPH: 4.7 seconds
• TOP SPEED: 196mph
• ECONOMY: 23mpg
• UK SALES: 71
• PRICE NEW: £62,950 (2005)

TECHNICAL DATA FILE E60 Alpina B5 S

• ENGINE: 4.4-litre supercharged V8 H1 BMW N62B44
• MAX POWER: 530hp @ 5500rpm
• MAX TORQUE: 535lb ft @ 4750rpm
• 0-62MPH: 4.6 seconds
• TOP SPEED: 197mph
• ECONOMY: 23mpg
• UK SALES: 12
• PRICE NEW: 69,950 (2008)

The supercharged 4.4-litre V8 made 500hp and 516lb ft of torque