It may have a discreet four-door body, but it eats Porsches for breakfast. Alpina's B10 Bi Turbo is also a bit of a bargain

Out of all the cars Alpina has built, it was its work on the E34 which, more than any other, has attained legendary status. Think about if, the company's main competition came from the M division themselves and it produced the astonishing M5, so just how could Alpina upstage that? The answer came not by starting off with an M5 but by fettling the 535i, a car that, although good in its own right, lacks the outright dynamism and sheer ability of the M car. The reason was quite simple, Alpina's engineers wanted to produce the car before the M5 arrived and do it their own way with no influence from the M-division.

Burkard Bovensiepen, the founder of Alpina, is always keen to stress that his company is a manufacturer and not a tuner and to that end, all its cars have fixed prices, warranties and a level of build quality that is at least the equal of BMW itself. Its 5 Series supercar slayer arrived in 1989 and was available in two flavours: the normally aspirated and rapid B10 and the absurdly rapid B10 Bi-Turbo.

The B10 was a logical development of the E28 version that had wowed the world through the Eighties. Lightweight Mahle high-compression pistons, a revised cylinder head and a new camshaft were all fitted at the Buchloe factory in southern Germany. Together with remapped fuel injection and a more efficient, free-flowing exhaust system, it developed 260bhp and 237lb ft of torque - enough to propel it from a standing start to 60mph comfortably under seven seconds.

Of course, its work wasn't just restricted to the engine bay. Shorter and stiffer Bilsteins were fitted, as were the signature wheels: Alpina 17-inch, lightweight 20-spoke alloys. The gearing was lowered to 3.91:1 and a whole range of interior options were also available. The E34 platform was a good one to work from and these alterations brought the best out of it, but there were some problems, however. Firstly, it cost over £40,000 once a few options had been selected, around £15,000 more than the 535i. It was also slower than the M5 and the previous incarnation of the B10, the combination of the extra weight over the E28 chassis and the power losses from the catalytic converter took their toll. To avoid losing its edge, Alpina needed more.

The company found it in the form of two Garrett T25 turbochargers and fitted them in parallel to avoid the lag problems assoclated with large turbos. A further 100bhp was on tap, enough to fling the huge saloon at the horizon. There are no speed limiters on Alpina cars and the top speed of l80mph and the 0-l25mph time of 20.1 seconds left no one in any doubt that Alpina was back

Just 507 were made and yet, because little is known about them, they are now extraordinarily good value. Fifteen grand will buy you a very good example and for a car that has been described as the world's fastest saloon car, thats got to be a steal.

There are pitfalls to be avoided and there's plenty to be aware of when buying one now. But there always is when you are considering any car with a decent level of performance. You have to be aware that despite the small price tag you are still buying a car which is a decade old and cost around £70,000. But if you find yourself a sound example then ownership will have no extra frustrations and you will have a very special car indeed.

Checking them out Very few of these cars come up for sale in the private classified ads but finding one isn't as difficult as you might imagine. The UK Alpina specialists, Sytner of Nottingham and L&C of Tunbridge Wells, may have one and both Birds of Uxbridge and the independent Motor Company have both had examples for sale. MCP Motorsport in Norfolk has a regular supply, specialising in importing these cars from Germany and often have a couple in stock. MCP only buy the best and have almost cornered the market in these models. Of course, it is possible to import one yourself, although this can be risky and time consuming. Unless you are familiar with these cars, our advice is to go to the experts.

The important point to note about these cars is that only the correct parts should be used for both maintenance and repairs and this can be a problem now that the value of these cars have dropped. Many buyers have bought them thinking they are not going to cost more to run than a similarly priced hot hatch. When they realise they can't afford it corners are cut, services missed out and substandard parts are -fitted. When that happens things can start to go wrong very quickly. Proper maintenance may not be cheap, but it is the most economical way in the long run, Unlike some of the smaller tuning outfits, all parts are still available so there's no excuse for not doing it right.

Overall though, there is little to worry about in terms of reliability over and above that of the M5. Despite the extra work, both engines are strong even if the full turbo boost has been used on a regular basis on the Bi-Turbo. The boost is adjustable by way of a knob in the centre of the console (in the German cars it is labelled Ladedruckregelung) between 1.4 and l.8bar. The turbochargers made by Garrett have shown have not shown any major failings, unsurprising considering it's expertise in this field. In front of the radiator you will see the massive intercooler that takes up the entire area from the grille to the lowest point of the front splitter. Again, it is reliable but you should examine it for signs of leaks as it is expensive to replace. Any oil leaks are bad news as the engine will have to be removed for this to be corrected and it can occasionally be found on very high-mileage cars. The timing chains will need to be replaced before 150,000 miles or you run the risk of them snapping. If that happens the engine will self-destruct. Replacing the chain is expensive though (approximately £2000), as again the engine has to be removed. If you are doing this job it's worth replacing all seals, sprockets and tensioners at the same time.

The gearbox Alpina chose to use was not from BMW but a five-speed Getrag 290 and it has proved a very good choice as it is well up to the job, lasts well and has a very sweet change to boot. Any problems will be immediately apparent on the test-drive, so listen out for noisy bearings with the car at idle as this can cost as much as £1000 to rectify. The synchromesh is also expensive to fix so ensure there is no graunching when selecting a gear, if it fails it usually becomes apparent in third. Clutches last well if they are not abused, despite the power and the diffs have proved to be unburstable.

Alpina fitted 13-inch vented Lucas discs with four-pot calipers and they do a great job of slowing 3733 lbs of metal from very high speeds but their life span will depend entirely on the weight of your right foot. Drive hard and the pads will need replacing at every service and if you go to a track they can be cooked in a day. Genuine Alpina pads and discs are horrendously expensive, but alternative discs can be sourced and the Alpina pad back plates can have new friction material fitted.

Pay close attention to wear on the front tyres, if it is uneven then the likely culprits are worn ball-joints. If you are suspicious, listen out for clonks and rattles over bumpy roads and it's important not to miss this as it costs £400 to correct. The steering was the standard BMW set up and it shouldn't feel vague because that's another £250 bill, this time for track-rod bail-joints. The Bilstein springs and dampers should last 70,000 miles: and if they are weak they will patter over the bumps, and ensure that the car appears level from side to side.

Rust is not a major concern on the E34, so if it is evident, it is likely your prosective purchase has had some dodgy body repairs. All the parts are available, but again they are quite expensive so if the car that you are buying needs work then the sale price should be adjusted accordingly. The front splitter can suffer quite badly with stone chips, especially if it has spent its life bombing up and down the autobahn.

Inside, the interior lasts as well as the standard 535i, so there are no problems that won't be obvious. Alpina offered its own interior option with anthracite cloth and a leather steering wheel complete with the Alpina emblem. All 507 have a silver-plated numbered plaque on the centre console, which is helpful when tracing an individual car's history.

Second Opinion Specialist dealer, Martin Pearse of MCP Motorsport. has probably sold more E34 B10 Bi-Turbos in the UK than anyone else and he has a passion for these cars. 'They're in my top-ten list of cars of all time and in my view it is the car that BMW should have built,' he told us. 'They are 30 to 40 per cent better than the M5, being more powerful, better balanced and more economical. The standard BI0S are not worth bothering about but the Bi-Turbos certainly are and if you use BMW parts rather than Alpina items, running costs are containable. We have an inventory of all parts and their numbers, so we can source everything required. If you need a new exhaust a bespoke one can be made for £600, whereas the Alpina version will cost several times that.

One point to be very aware of is that they are very easy to dock so take your time when buying one of these and ask lots of questions. As it's a small market, we keep track of all the cars, so if something is wrong it stands out a mile. Most cars have covered decent mileages because they were bought by businessmen who need to get fom one side of Germany to the other in a hurry, they weren't icons and were seldom bought by private individuals. Find yourself a decent example now though and they really are very nice cars to own.

The Owner Clint Spearpoint was in the very fortunate position of being able to afford one of these cars when he was just 21. 'I didn't know anything about these cars until a friend of mine bought a standard B10 3.5 and told me that there was also a turbo version so I went and tried one and that was it. I bought it there and then, I was so excited about it I didn't really ask enough questions about the car. Fortunately I didn't have any problems with it but I know I shouldn't have let my enthusiasm get the better of me. It's hard to rationalise in the face of such shattering performance - I'd never been in a car as quick as that! It was just astonishing. 'At one point I put it up against a Skyline and a 911 and nothing came past me, it was a real wolf in sheep's clothing. I had it for 18 months and if it wasn't for my desire for a soft-top I would still have it now. The lure of an M3 convertible proved too much, but there are times when I regret it, in fact every rime I put my right foot down!

Thanks to

Martin Pearse at MCP Motorsport for his help in compiling this feature.

Tel: 01263 822481

Web: mcpmotorsport.co.uk

Steve Batty at The Independent Motor Company for sourcing the pictured car.

Tel: 01169713939

Web: www.bmwmpower.co.uk