With their Formula One participation poised to cease, BMW are determined to succeed in the European Touring Car Championship next year. The new 200bhp M3 is the company’s secret weapon, as Doug Nye discovered in Tuscany, but how will it fare against the other homologation specials from Ford and Mercedes – Fast Lane
BMW Motorsport Gmbh is without question one of the most experienced and effective of all competition-orientated research and development units. Its subtle M-motifs have distinguished BMW’s remarkable M5 performance four-door saloon and the mouth-watering-if-very expensive-M635CSi Coupe, and now these respected badges are appearing on what will initially at least be a 5,000-off homologation batch of 3-series two-door saloons intended to legalise the model for International Group A touring car racing from the start of next season. The new model is called, simply, the BMW M3.
Now the good news is that this top-of-the-range 3-series feels very nearly as good as it sounds with its 7,000rpm 16-valve four-cylinder fuel-injected engine delivering 200 horsepower. Such sheer, basic grunt is accompanied by an extremely high standard of refinement, ride and roadholding which is provided by extensive modification to both the basic 3-series bodyshell and the running gear.
But the bad news is that we shall not be seeing the model here in the UK. Now considering that this is one of the most enthusiastic of performance-orientated markets, why won’t we be getting it Essentially the tall 2.3-litre engine is a slant-four, angled to the right to minimise bonnet height, induction on the left, four branch fabricated exhaust manifolding dropping down to the right. Motorsport’s M3 engineering group, headed by ex-Ford and Audi boffin Dr Thomas Ammerschlager, has toyed with ways to insinuate right-hand drive steering beneath that slant-head and clear of a suitably efficient exhaust manifold, but they have concluded that it can’t be done.
“We would have to replace the ‘fan’ manifold with a cast one and that would probably cost us 15 maybe 20 horsepower”. A right-hand drive M3 would therefore be strangled down to around 180bhp, which is only nine more than the sprightly 325i which is already available over here. The price premium on the M3 will be such that a 9bhp advantage over the next model down simply would not make sense, Now that is a pity because the M3 in unstrangulated form really is quite an impressive beast, though in what I consider to be a surprisingly unexciting way . . . Let me explain.
Essentially, Motorsport regard it as the logical successor to the M1 mid-engined Coupe which they struggled so hard to build between 1978 and ’81. They justify this stance by explaining that it is the first BMW since the M1 to be designed and built for competition from square one without compromise, beyond those demanded by the relevant racing regulations.
You see it is not just another hopped up basic 3-series saloon. It is far more fundamentally a new and different model, a mere 3-series lookalike, and a true ‘homologation special’ because, after insisting that they want to bow out of Formula One engine supply. Munich is fiercely determined to achieve real success again in the European Touring Car Championship, as of yore.
In fact the company’s commitment to the new M3 is such that it becomes the first M3 is such that it becomes the first BMW ever to be developed by Motorsport Gmbh for production on BMW AG’s volume lines. Motorsport Gmbh itself in Preussenstrasse has only 315 employees, two-thirds of them design and development engineers rather than production people, and from September this year their new plant in Garching-another suburb of Munich-will be building the M5 in relatively puny numbers while AG’s main plant thunders out 5,000 M3s hopefully in time for Group A homologation (acceptance) in March, next year. In fact Preussentrasse produced 250 M5s in 1985, it and Garching will complete a projected 450 this year, then production is planned to rise to 650 next year and to 1,000 in 1988.
The idea for the M3 was first floated in Summer 1981 just as the 456th and last M1 was being completed.To provide Bee-Emm with the greatest possible startline advantage with the 2.5-litre Group A class, it was necessary for as many circuit-racing tweaks as possible to be designed into the production model as standard.
Consequently the basic 3-series steel sheet was modified to carry widely flared pressed-steel-note, not Tupperware ‘add-on’ –wheel arches as standard, capacious enough to accommodate 10-inch wide wheels as permitted under Group A for cars up to 2,500cc.
Wind tunnel test results indicated an improvement in Cd by raising the standard 3-series’ boot-lid height-Mercedes-Benz of course having come to the same conclusion with their 190E Shells. Rear screen rake was eased three-degrees to provide smoother lead-in to an end-plate mounted rear wing. Plastic composite moulding technology provided the new raised bootlid, rear-screen pillar outer skin and sandwich-construction wing components. Suspension development produced what Amerschlager’s group considered the proper compromise between road and track settings, and ABS braking with enlarged discs and stiffened calipers was adopted as standard with power steering. Neither ABS nor PAS will appear on the finalised Group A racing M3s unless there is some quantum leap in either technology.
Ever since their fiendishly-complex Apfelbeck-headed radial-four-valve competition engine of the mid-‘60s, BMW have been to the fore in the arts of four-valves-per-cylinder head design and once they shook the radial valve format from their minds and adopted a more simple pent-roof layout their power units, developed under the direction most notably of Paul Rosche, became fearsomely effective, and reliable.
They have won six European Formula Two Championship titles, in addition to numerous touring car trophies and in effect the new M3’s four-cylinder 16-valve head represents two-thirds of the M1-originated 24-valve six-cylinder which lives on in the current M5 and M635CSi. The Rosche/Ammerschlager team preferred the four-cylinder to a ‘six’ because its relatively shorter crankshaft is inherently stiffer while the in-line four-cylinder layout avoids the torsional vibration periods inherent with a ‘six’, promising higher revs, hence more gas passed through the engine, hence more power, with greater reliability.
So effective has this choice proved to be that the standard M3 is now red-lined at 7,000rpm-not half bad for a sizeable ‘four’-and if the driver is that way inclined 7,500rpm can be used, though if sustained I feel it would probably invalidate the guarantee . . .
Of infinitely more importance to Motorsport’s engineers is the promise of a sustainable 10,000rpm in Group A racing form, and that I do find impressive. . .
The age-old BMW 1,500-derived cast-iron block provides the basis of the M3’s engine, bored-out now to 93.4mm. This overbore necessitates casting the two centre-cylinder liners in one unit-as is already the case with the six-cylinder engines-and this itself increases unit stiffness. Stroke is 84mm for a 2.302cc displacement, and the forged, eight-balance-weight crankshaft rotates in five main bearings. It’s a wet-sump unit with careful baffling and a separate oil-cooler matrix tucked away behind the car’s aerodynamic chin-dam.
Inside each pent-roof combustion chamber the four valves per cylinder are inclined respectively at 18-degrees (intake) and 20-degrees (exhaust), for an included angle of 38-degrees. The inlet-valve heads are 37mm-nearly an inch and a half-in diameter, exhausts 32mm, just over an inch and a quarter.
There’s a single central spark plug per cylinder, and the valves are actuated by duplex-chain-driven dohc-the Formula. One variants of this block, remember, using gear-driven camshafts instead. Bosch Motronic digital fuel injection is fitted with intake air volume engine-management sensing. There are four separate intake manifolds, each with its own independent throttle butterfly.
Significantly BMW intended to sell the M3 (and also the M653CSi) in the USA, and their development provides a catalysed M3 (as now demanded increasingly in Europe) with only five bhp less than the unconverted version. Its peak 195bhp and the free-flow’s 200bhp are both developed at 6.750rpm, while peak torque is exerted at 4.750rpm. BMW claim 0-100kph (0-62mph) in just 6.7sec for the un-catalysed model, 7.1sec with converter.
Externally the M3 is unmistakable with its lowered suspension, extended wheel arch bays, front and rear air dams, that rear wing with its full-width unsupported span offering an uninterrupted working undersurface, and less steeply raked rear-screen.
In fact glass is a very rigid material, and Ammerschlager has specified bonded-in front and rear screens for the M3 which materially improve the bodyshell’s torsional rigidity, a vital factor in achieving competitive handling for the racing version, which will have a minimum 300bhp and rev to 10,000rpm, and maybe more . . .
Standard moulded composite bumpers match worldwide requirements including the USA’s nutty-Norah standards, the plastic boot-lid is 40mm, 1.6in, higher than the standard 3-series and assists in a 50 per cent aerodynamic lift reduction.
Underneath, front suspension geometry changes have tripled castor to ensure directional stability at 140mph-plus top speeds. Anti-drive is built in and power steering has been carefully weighted to give more feel. Redesigned front stub axles accommodate larger-than-standard racing-orientated wheel bearings. Anti-roll bars appear front and rear, picking-up outboard of the spring struts to exert “almost twice the standard spring effect” Gas-filled dampers have been selected with very firm settings, and different response curves selected during Bee. Emm’s development testing.
While rear suspension is essentially standard 3-sereis, save for uprated damping and spring-rates, the entire M3 brake system is new, using larger, thicker discs clasped by stiffened heavy-duty calipers. Wheels are 15in diameter cast-alloy as standard carrying 205/55 VR 15 tyres.
A new transmission system was necessary, a bonded-lining heavy-duty clutch now driving to a close-ratio five speed gearbox using what used to be known as the “ZF” change pattern, whit first across to the left and back. Ratio spacing is very close with fifth a true fifth, not an economy-style overdrive gear. There’s a 25 per cent locker in the final-drive.
So what’s it like on the road? Let me first declare an interest, or possibly prejudice. My previous experience of BMWs up to the 325i left me with hardly any impression at all, beyond the recognition that they very nicely engineered and well made and I felt generally both over-rated and over-priced. Nice, efficient, crisply dull cars, tending, despite their manufacturer’s laudable sporting activities, towards dull. Arrive at your destination, lock it up, walk away and you couldn’t remember what you had driven there in.
The 325i changed much of that; the M5 woke me up and the M635CSi quite bowled me over, so I regarded the opportunity of being let loose in a new M3 in Tuscany with relish.
Initial reactions were as follows; tight, comfy, sensible sports seat really locates you well. Gear change quite stiff, rather long travel for such a sporting car, soon became accustomed to the odd gate-yes well, it wasn’t the first time I’d used that ZF pattern (this is called over-confidence).
Out onto the autostrada near the spa town of Montecatini Terme it was impossible to try a maximum speed run due to heavy morning traffic but two features instantly impressed. Firstly it’s difficult to believe the M3 has such a sizeable four-cylinder engine beneath its bonnet. It revs so freely and so smoothly it could easily be a six, and almost a turbine. It’s responsive and willing, and Motorsport have achieved that degree of refinement without the complication of Porsche 944-style separate balance shaft to smooth it out.
Yes, Motorsport’s preferred short-stiff block and eight-balance crankshaft really pay off exquisitely well.And then the chassis ride quality is superb. It is firm-damped, level and roll-free (on the road) yet there’s no skipping from crag to crag, nor any apparent penalty in excessive thump-bump road noise. I was very impressed. Overall the M3 is a laudably quiet performance car.
Neither do those low-profile tyres notably grab and white-line on longitudinal joints or runnels, this in marked contrast to the Ford RS Turbo which nearly broke my wrist in a wild runnel-deflection without actually hitting anything. Still hurts me occasionally, so it does.
Traffic clears near Pistoia, let’s try some oomph. Knocking down into fourth, floor the throttle and . . . disappointment.Not very much happens. Below 4,000-4,500rpm there’s apparently nothing at home. The M3 accelerates sure enough, but there’s nothing at all dramatically neck-breaking about it. There’s just a firm, constant thrust as the autostrada streams by, the pressure increases smoothly up around 5,000rpm, and there’s a robust hard edge to the exhaust note higher in the range at peak power. Up around 120-125mph we ran out of clear road, there was obviously far more to come towards BMW’s claimed maximum of 143mph. but like so many of the M-series this M3’s true pace becomes more apparent on paper than on the open road where its character is really so restrained. It is a top-end autobame stormer rather than a traffic-light sprinter, and although it can fight its corner most effectively there too, that is not its forte.
From 50 to 75mph takes only 7.5sec in fourth, and as we would shortly discover, that smooth engine is also quite flexible when pulling from low speeds in the higher gears, short of ‘racing it’ through the “box.Up into the mountains towards Vinci-Leonardo’s home-town-and on towards Scarperia and the Mugello autodrome the M3 proved a most effective point-to-pointer on winding roads, though on one sharp dusty right hander it showed the fierce understeer now built in to all road BMWs for stability in high-speed curves, and to kill their one-time reputation as wicked terminal oversteerers. But you just back off and it tucks in.
Then, selecting reverse during photography, our car’s gear-level snapped off in my hand . . .crystalline fatigue showing in the fracture, down in the tunnel an inch and a half above the bottom joint. “Pre-production!”, Motorsport’s men would roar. It had certainly lived a hard life in several previous days of press-testing.
With Grand Prix heroics in mind we drove on to Mugello. Trying another car on circuit it then became very evident that the understeer dialled in for the road has to be dialled out for the Group A racer, but equally clearly that a couple of days juggling with alternative spring-rates and damper settings would do the trick. Mugello itself is a tricky place, with a succession of varying-severity S-bends, two fast 90-degree rights (which you can link together into one 100mph sweeper) and three long open 180-degree plus curves in which, unless you were prepared to stuff it in tail-out, front-tyre scrub would take over and until you could wind off lock whereupon the tail would kick out at last.
And for all my ‘vast experience’ of that ZF gearchange pattern, I forgot it all in my first two laps learning the circuit, and having had the gear-lever in one car fracture totally, through no fault of my own. I now found myself trying hard to snap another. In scientific terms it’s called Driving Like a Rock-Ape, but mind prevailed over mass, the M3 survived, and so did I.
It proved so stable in faster turns you could really do anything with it. Minimal roll, back-off or sudden turn-in oversteer available at will, magnificently-weighted steering retaining sufficient feel to enable you to catch any slide, very powerful, again-responsive brakes performing without complaint beyond blackening the front wheels with pad-dust.
Eventually, after slithering up the kerbs, quite quick and never on the grass but never as smooth as I would have liked to be, I got it together, the M3 swinging lock-to-lock comfortably through the esses, spending perhaps two-fifths of every lap in long sustained slides, an indicated 124mph, just coming up in fifth before braking at under 150-metres into the hairpin beyond the pits.
It was hot and sunny and after 10 successive laps with bare slippery hands I was plain running out of puff, unlike Bee-Emm’s latest.It impresses as a thoroughly competent car, too refined to feel as neck-breakingly quick as its figures might suggest but oh so effective and efficient as a cross-country charger.
In comparison with its rival Mercedes-Benz 190E 2.3-16 and the Ford Sierra RS Cosworth, what d’you find?It is nominally 4bhp down on the albeit-turbocharged Ford but a whopping 15bhp up on the Merc. It has 177lb ft of torque at 4,750rpm, a little more than the hapless Merc but a whopping 26 less than the much less-expensive forced-induction Ford. It is slower flat-out than the Ford but considerably quicker than the Merc, and its 0-62mph time is 0.1sec quicker than the turbo Ford and a full 0.6sec. quicker than the Mercedes.
From this comparison the Mercedes, which is fully 132lb heavier than the M3, is not only the heaviest of this trio but also the least powerful-by a considerable margin-it has the lowest top speed – again by a considerable margin – and is the slowest 0-62mph, yet despite all these minuses it is still the most expensive; in Germany DM58, 140 against DM58,000 for the M3 and a relative-bargain DM-48, 420 for the cheap and cheerful Ford.
On paper the turbo Sierra Cosworth predictably out—performs the new M3 on power, torque and top speed but is 88lb heavier which, together with its turbo wind-up characteristics, explain its acceleration deficit. The significant point must be that the M3 performs without recourse to forced induction and the thermal stress that imposes, so promises greater reliability.
Neither will the Sierra Cosworth and the M3 fall into the same Group A class, by virtue of the Ford being turbocharged.
Motorsport Gmbh having now unleashed their M3, it is up to BMW AG to complete that initial 5,000-off batch in time for their FISA homologation target date next year. If they manage it in time the 2,500cc Group A class will surely become another Bcc-Emm preserve.
But it remains to be seen whether or not the UK will ever win itself a right-hand drive M3. I got the impression that Motorsport’s planners don’t understand the-British attitude to left-hand drive, despite my patient explanation that we drive on that side to keep our sword- hands free. Will demand make dropping another model here to make logical space for the M3 seem sensible? That must be very doubtful.
Irrespective, it‘s a very impressive little beast, but never the wicked fire-breathing projectile some might claim it to be. It’s above and in some ways beyond such undignified behavior. Because it is a BMW after all…
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November 2, 2009
1986 - 1989, Articles