As has already been proved, the BMW M3 makes a great race car, and BMW dealer Hexagon is out to reinforce the point this year. Graham Jones enlisted the help of saloon ace James Weaver to try the firm’s car – Autocar
Bill Nathan, service director of BMW dealer Hexagon of Highgate, wears a John Watson lookalike helmet when he’s racing, and therein lies a clue about the company’s past. Those who followed motor sport in the 1970s will undoubtedly recall that Hexagon has fielded cars as diverse as a Trojan 101, Brabham BT42 and BT44 and for such drivers as Willie Green, Carlos Pace, Derek Bell, Damien Magee and John Watson himself.
The cost of participating at this level, however, became prohibitive even for someone with the enthusiasm for motor sport of Hexagon’s chairman, Paul Michaels. As a result, the company quietly withdrew from its motor racing commitments. As anyone who has been bitten by the bug will know, however, racing circuits are inexplicably addictive places and after several years’ absence, the Hexagon name reappeared. Initially it was on the flanks of a BMW 320i, taken straight off the second-hand car lot and plunged into a season of production saloon racing. In 1986, this became a BMW 325i, which evolved into 325i Sport specification by the end of the year.
This season the company is fielding its most potentially competitive “tin-top” to date; an immaculately presented BMW M3 which will be driven by Nick Atkins in the Monroe Championship and Nathan in the Uniroyal Championship. The two will team up for the prestigious Willhire 24-hour race at Snetterton with additional driving strength coming from Pink Floyd drummer Nick Mason. On paper, at least, the BMW M3 in Group N guise looks to be a strong contender for production saloon Class B honours, but does theory translate into practice in this case?
To answer that particular question, we brought M3 and racing driver James Weaver together at a wet and windy Silverstone. By the end of the day, we had the most graphic evidence of the car’s potential for in the course of a dozen laps of the Club circuit in treacherously slippery conditions, Weaver had achieved a best lap of 69.0secs, 0.1secs inside the Class B lap record presently held by Ian Taylor in a Mercedes 190E 2.3-16. Regular driver Nathan, who was present for the exercise, predicted that in more favourable conditions it should be possible to shave at least a further 2secs off that time.
Until the car has turned in that sort of lap time in competition, however, it remains a hypothetical target. Nonetheless, there seems ample evidence that the M3 is going to be a really competitive production racer, particularly bearing in mind that it is only at the beginning of what Nathan envisages as a two-year development programme.
There are two ways to build an M3 race car. One is to purchase a “kit car” from BMW and the other is to strip out a road-going M3 and rebuild it to the desired specification. The former, which is to Group A specification. The former, which is to Group A specification, includes a body shell fitted with roll cage, engine modified to produce 300bhp at 8000rpm and 199lb ft of torque at 7000rpm, uprated springs, four-pot callipers, 9ins modular wheels and Pirelli tyres. It also costs DM 150, 000, or approximately £52, 000.
The other route to M3 racerdom is the one followed by Nathan and his dedicated crew at Hexagon – convert a road car to competition use. It also makes more sense as far as production racing is concerned since the rules require the inclusion of much of the standard car’s trim, which is simply not available with the Group A kit.
In theory, Group N rules allow very little in the way of modifications over the standard car, and a closer perusal of Hexagon’s racer bears that out. There are the obvious stickers which adorn the car, but take those away and about the only clue to the car’s weekend warrior lifestyle is the ride height. The combination of low-profile BF Goodrich TA2R (produced in “shaved” form by the American type company) radials and lins shorter springs has wrought this change in the M3’s stance. Shock absorber choice is free under production rules and at the time of our track test, the BMW was fitted with Konis, the main drawback of which is that they cannot be adjusted in place on the car. Hexagon has commissioned Sachs to produce an externally adjustable set of shock absorbers and they will be fitted just as soon as they are available. The M3 already has anti-roll bars at the front and rear and these are retained in their standard diameters.
The engine is so far untouched, apart from the rev limiter being reset from the standard car’s 7300rpm to 8000rpm, which is an indication of just how well the standard engine is assembled at the factory. Nathan’s plan is to do two more races on the engine – it’s done three to date – and then strip it down and re-blueprint it in the Hexagon workshops. Even so, he isn’t expecting the sort of power increase which might be available from carrying out this exercise on other, less well assembled power units. Although the M3 has not yet had a session on the rolling road, it is estimated that the power output is presently about 220bhp (the road car is rated at 200bhp at 6750rpm), a figure which will eventually rise to perhaps 235bhp. This compares favourably with the outputs for the Mercedes 190E 2.3-16 and Escort RS Turbo, the two main rivals to the BMW in Class B. The Sierra Cosworth engine, by comparison is estimated to produce 260bhp with inlet restrictor in place and 285bhp without. It is therefore fairly clear that, at least as far as production racing is concerned, the BMW is unlikely to be an outright race winner, although it will remain the car to beat in its class.
In any event, the under-bonnet scene is virtually the same as for the standard car, with the exception of a robust looking strut brace to provide the engine compartment with a little extra torsional rigidity.
As far as the interior is concerned, modifications are really limited to safety-related items. These include a full roll cage, Corbeau competition seat, six-point harness, fire extinguisher, electrical master cut-out switch and additional warning lights. Carpeting has been removed, but otherwise the interior trim is retained.
The boot is devoid of a spare wheel (production rules allow the road car’s weight of 1200kg to be reduced by five per cent) but contains a full-size battery plus additional fuel tank fitted immediately behind the rear bulkhead. This is in addition to the two standard tanks situated under the boot floor. The braking system which include ABS, remains to standard specification and is perhaps a little suspect on circuits like Donington, with its “bus-stop” chicane, and Mallory Park with its famous hairpin. Only further testing, however, will reveal if there is a problem in this department.
The question we wanted answered, though, was just how good a production racer is the M3 in its present state? In best race commentator fashion, we thrust the tape recorder microphone up James Weaver’s left nostril as soon as he stepped from the BMW and asked him for his initial impression. His response could best be described as enthusiastic.
“The main thing is that the car is just enormous fun. Normally the trouble with Group N cars is that they won’t put the power down. In cornering, they understeer when you turn in and because they spin the inside rear wheel, you can’t hold a slide. As a result, they can be very tedious to drive. This, on the other hand, is terrific.”
“It’s so nicely balanced and has sufficient power and traction that you can drive right through the understeer. If you lift off a bit, it will just settle down, and if you apply more power it will go into a beautifully controlled tail slide. You can just steer it on the throttle and it gives you bags of confidence.”
The chassis was therefore clearly a strong point, but what of the engine? Once again, Weaver had nothing but praise for the BMW. “It’s fabulous. It’ll pull up to 8000rpm without any bother, but then again, the road car revs beautifully as well. In fact, about the only difference between that and the racer in terms of power delivery is that the racer seems to rev on a little bit better – the road car feels just as smooth.”
All these superlatives were undoubtedly deserved, but we have yet to hear of the perfect race car. Did the M3 have any obvious weak points, we wondered? Weaver felt there was a couple of areas where improvements could be made, one of the most important being the choice of final drive. Presently the M3 is homologated with only one final drive for Group N competition, a 3.25 crown-wheel and pinion, which results in overly high gearing for a track like the Silverstone Club circuit. Weaver explained: “The engine will pull about 7500rpm in fourth gear for the braking point at Woodcote, whereas it should be about 8000rpm and then into fifth. At the same time, second is too short for Becketts and third is too high. Third is good for Woodcote but a little short for Copse. To race it here in the UK, you definitely need a short rear axle.”
Bill Nathan had warned Weaver that the shock absorbers were set at their maximum stiffness and could not be adjusted without removing them from the car. After his stint at the wheel, Weaver concurred: “The car does feel a fraction too stiff at the back and, as a result, it doesn’t seem to put its power down quite as well as the road car when I tried it this morning. For me, the race car could be a little bit stiffer at the front and then you could almost trick it into turning in. Then you could get the power on just a fraction earlier, drive through the understeer, and I think you would be just that little bit quicker.”
“Overall, though, the car is very good. The ABS brakes are terrific – you just get a lot of pedal thump, although that may be because the discs are a bit warped on this one. I think the limited-slip differential might also have lost a bit of its preload, which could explain why this car isn’t putting its power down as well as the road car.”
“The other two items which merit comment are the steering and roll stiffness. In the normal course of events, the race car runs with the power steering pump connected. There isn’t any assistance today simply because the belt is broken. Even so, the steering is very light and helps make the car very easy to control. Bear in mind, too, that the pump does soak up power.”
“As for roll stiffness, my feeling is the car doesn’t have quite enough. Driving the road car around the circuit, it is obvious that it rolls a fair bit. This one doesn’t roll as much, but it still needs more roll stiffness. You can tell by the way it just flops around a little in some of the corners. The problem is, they have to retain the standard anti-roll bars in production so there may not be a lot that can be done. The level of grip is quite high and that, in combination with a fair amount of body roll, is what can make a car break away abruptly. Quite a lot of cars have a high base level of grip and then when they get away from you, they just get so out of shape, you become frightened to use the grip. With the M3, that is not the case – you can use it to the full because it remains progressive at all times.”
So much for the detailed appraisal. What was Weaver’s overall verdict of the BMW M3 in production racing guise? His answer was decisive: “I haven’t driven that many group n cars, but it is the nicest one I’ve driven by a long way. I raced a Capri in the 1984 Willhire race and it was so frustrating because you just could not put the power down and therefore drive through the car’s natural understeer. You can learn to drive it quickly, but with the M3, you can drive it like a racing car – brake, turn in, and accelerate – and that makes it very satisfying. It handles very, very well.”
As a parting shot, we couldn’t help but ask Weaver for his verdict on the road-going M3. “Given that this is a car which has been produced for Group A homologation purposes, it is a very civilised road car – far more so, for instance, than the Sierra Cosworth, which seems to bang and crash and jump all over the road at times.”
“I’m very much into O-cars at the moment and I think the ultimate form of this for road use would be something which looked like a standard 3-Series – maybe with a deeper front spoiler or something, to make it a bit more stable – with all the M3 running gear. For me, the rear wing and flared wheel arches are just too outrageous for the road; it looks fabulous in Group A trim, as does the Sierra, but it’s a bit over the top for the road. I would happily have that package in a standard-looking 3-Series shell with a 318 badge on the bootlid.”
The verdict to emerge from the day’s activities at Silverstone? The M3 makes a refined, civilised road car while providing the basis for a tremendously competitive racer. BMW would look to have a sure winner on its hands both in the showrooms and on the circuits.
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January 7, 2008
1986 - 1989, Articles