ALPINA-CONVERTED BMW 3.0 Si SALOON

BAVARIAN BOMBSHELL

(Autocar, 29 March 1973. By A.D. Shanks. UK.)                    

There exists in Europe an elite of tuning companies who, with the assistance of the manufacturer of the car of their choice, are able to concentrate exclusively on producing high performance versions of just one make of car. One thinks immediately of Abarth in conjunction with Fiat, of Broadspeed with Ford, and Daniel Richmond of Downton fame in conjunction with British Leyland, and in the case of BMW, the name of Alpina has become universally renowned.

   This enterprising German company, that started life in a sewing machine-shop, can be justifiably proud of their position as the biggest supplier of tuning equipment for the BMW range of cars. But unlike most other tuning companies, Alpina have the problem that BMW already produce their own high performance version of each of their model ranges. It has become necessary therefore, for Alpina to go very considerable trouble to improve on the factory article.

   This is particularly so with the 3.0 Si saloon which we have been fortunate to have the use of recently. In standard form, this five-seater saloon is already capable of accelerating from rest to 100mph in only 20.8sec and has a maximum speed in excess of 130mph, and some would surely argue the necessity of improving on these already most impressive figures.

   The answer that Alpina have come up with is both radical and expensive, and Alpina have not spared anybody’s reputation in getting to what they consider to be the ultimate in a road-going BMW saloon.

   Gone is the computerized Bosch fuel injection, to be replaced by the simpler mechanical Kugelfischer system, with its priceless virtue of being adjustable. Gone also, are the famous triple pot combustion chambers, in favour of a hemi-head design that is more in keeping with the quest for sheer power. The standard clutch has also been replaced by a heavy-duty unit, and the thickness of the disc brakes has also been increased in the light of the increased performance potential.

   So much for the items that have been replaced, what of those that have required only alteration? Starting with the engine in addition to the combustion chamber changes, the valves and ports are altered, while the compression ratio has been increased from 9.5 to 10.5:1. A 300 deg overlap camshaft and an enlarged diameter exhaust system complete the underbonnet work. The suspension is altered considerably at both ends of the car, most noticeably at the rear. Stronger springs and Bilstein dampers are fitted all round, and slight negative camber at the front is combined with considerable negative camber at the rear. The anti-roll bars are adjustable over a large range, and it is therefore possible by adjusting the roll stiffness at either end of the car to tailor the handling characteristics to one’s own taste.

   The remaining items of the Alpina package are a set of beautifully-made 7 in. wide magnesium wheels which carry massive 195/70-14in. Michelin XVR tyres, a neat black glass-fibre “bib” front spoiler, a limited-slip differential, an electric fan, a higher final drive ratio of 3.25:1, and the engine is rev-limited at 7,100rpm, instead of the 6,500rpm rev-limit of the standard 3.0 Si.

   On the road, the Alpina 3.0 Si displays the same Jekyll and Hyde characteristics as the standard version, only more so. Despite the extensive engine tuning necessary to gain an increase from 200 to 250 (DIN) bhp, there is a total absence of any temperament even after prolonged running in slow moving traffic, and the engine is ever ready to pour out its effortless performance at the slightest bidding. But it is on the open road that the car really comes into its own.

   At 70mph a changedown to third gear enables one to rocket up to 100mph in under nine seconds when a change to top gear can have 120mph showing in only a further 14 seconds. This kind of performance is usually associated with cars of twice the capacity of the BMW, very few of which can rival the five-seater comfort of this saloon. The cost in terms of petrol consumption is not as heavy as one might imagine, our overall consumption of 18.4mpg is remarkable for a car of this performance and size.

   The responsive handling of this very large car was a revelation. There is a taut feel to the whole of the suspension, and while this gives a harsh ride on indifferent roads or at low speed, as the speed builds up the firm, well-damped suspension instills considerable confidence in the car’s ability to cope with any combination of surface, or irregularity. The delightful thick-rimmed steering wheel reduces minor changes in direction to a mere flick of the wrist. The neutral handling can be changed to oversteer at will, and within limits, the application of any amount of power can be balanced by the quick steering.

   It is hard to believe that the steering is power-assisted, as the amount of feel that is transmitted to the hands is just right. It is only after effortlessly manoeuvring this very large car into a tight parking space that one realizes that one is not solely responsible for the results.

   The gearbox of this Alpina version shares the same internal ratios as the standard 3.0 Si, but the fitment of a 3.25:1 rear axle ratio in place of the 3.45:1 unit of the 3.0 Si, gives a worth wile decrease in engine speed at fast cruising speeds. It is important to make the point that the impressive acceleration of the Alpina is not the result of sprint gearing. The car is quite capable of cruising all day in excess of 120mph with a marked lack of noise or fuss. Although the gears are widely spaced, the wide power band of the engine effectively masks the gaps. The only criticism that we would level at the gearbox concerns the considerable rattle from the layshaft. This is most noticeable if any attempt is made to accelerate strongly in third or top gears from less than 1800rpm, and prevented any attempt to take acceleration figures in top gear from 20mph. While praising the gearbox as fitted to the test car in general, we would certainly like to be first in the queue when a close-ratio five-speed gear box becomes available.

   Like the Bosch petrol injection of the 3.0 Si, the Kugelfischer system fitted to the Alpina does not have any form of mixture enrichment, and to start up the car, you simply turn the key. After a few preliminary sputters, the engine will usually catch, but the precaution must be taken of avoiding wide throttle openings during the first half minute of running. What one must never do is to touch the accelerator when starting the car, whether the engine is hot or cold. Our experience suggests that the injection tuning is critical for easy starting.

   The standard 3.0 Si seats are comfortable enough, but lack sufficient lateral location to cope with the extremely high cornering forces that this car is capable of producing. In addition, the test car was fitted with inertia reel seat belts, which prevent one from strapping oneself in tightly. The omission of proper bucket seats on a car of this character, not to mention price, seems curious. In all respect of comfort and appointments, the Alpina version is well up to the high standards of the normal 3.0 Si, the spacious interior providing more than enough room for four or five adults and their luggage.

   To put the performance of this car into perspective, one must look to the real exotica of modern cars to find any that are as fast either in top speed or acceleration. It is for instance identical in performance to the Jensen SP and faster than the 300SEL V8 Mercedes-Benz. The acceleration from rest to 60mph is identical to the Morgan +8, and the top speed is some 20mph faster than the Jaguar XJ6. Perhaps the most striking comparison of all is against the Maserati Bora which is only two tenths of a second faster to 60mph, and less than two seconds faster to 80mph.

   Of course, such performance does not come cheaply. The cost of the complete Alpina package adds £2,700 to the cost of the standard car, bringing the “show-room” price up to few pence under £7,000.

   However, it is possible to buy the units that make up the conversion as a number of separate items. The suspension parts can be bought over the counter from the concessionaires, and will shortly be available from a selected few BMW dealers around the countryside. BMW insists that they must carry out the fitting of these parts.

   At the present time, the Alpina 250bhp engine must be built up and fitted by Alpina in Germany before the car is imported, so there is an element of import duty included in the cost of this item. An alternative that might appeal to some is to have the 3.0 Si engine “blueprinted” in this country. The final result may not be as electrifying as the modified engine, but a worthwhile gain of 10 per cent is talked by the concessionaires.

   In conclusion, the point must be made that the Alpina 3.0 Si is a thoroughly practical proposition, and while we have dwelt on the performance that the converted car offers, this is not gained at the expense of any noticeable loss of flexibility, nor any reduction in the standards of road behaviour of the standard car.

PERFORMANCE CHECK

Standing ¼ mile
Alpina: 15.3sec (94mph)
3.0 Si:   15.7sec (89mph)

Standing kilometre
Alpina: 27.9sec (117mph)
3.0 Si:   28.7sec (111mph)

FUEL CONSUMPTION (Overall)

Alpina: 18.4 mpg (15.4 litres/100km)
3.0 Si:   17.4 mpg (16.2 litres/100km)