Ian Bracey's Ibec: Science in Clubmen's Formula by SIMON TAYLOR Reprinted from AUTOSPORT March 4, 1971
	There must be no more satisfying way of winning a motor race than doing so in a car designed, built and developed by oneself. Great designers like Colin Chapman of Lotus, Derek Bennett of Chevron and Eric Broadley of Lola started their careers by doing just that, but nowadays in the realm of professional motor racing such achievements are rare, apart from the deeds of men like Brabham, McLaren and Surtees in Formula 1. In the close competition of Formula 3 or Formula Ford it is a brave driver who tries to take on the best from the specialist manufacturers with a brainchild of his own.
	But in the lower echelons of club racing some classes positively encourage one-offs. To take only two examples, in Monoposto Formula events Brian Toft's Anco shows that a front-engined single-seater can still win races, while Brian Martin's Martin sports cars have won many club thrashes and held their own in international events. Of course the 750 and 1200 Formulae cater specifically for home-built cars.
	And in Clubmen's Formula, to take on the Lotuses and U2s, there are some beautifully designed and meticulously built machines which frequently do the winning in the hands of their constructors. None of them is more ambitious than the Ibec, the clubmen's car raced by Lloyds' insurance broker Ian Bracey. It hasn't won a race yet, for its first season last year was not without its problems and setbacks; but much was learnt, and the car looks like being very competitive in this year's new Shell Clubmen's championship.
	It is not quite right to say that the Ibec was built by the man who drives it, for he is just one of a dedicated little team of spare-time enthusiasts which includes electronics engineer Dennis Jones, development engineer Geoff Tubb, and another Lloyds' broker, Ian Walker. Moreover, a London university has been involved with the car right from the start.
	Ian Bracey has been connected with unorthodox machines from an early age: he and his dose friend Sir Jon Samuel began racing in their teens with an extraordinary machine called the Tiger Shrike, which was based on a kart. It came about after Bracey and Samuel, who had £160 between them and wanted to go motor racing, read up the RAC Blue Book and discovered that there were no minimum wheelbase, track and wheel diameter requirements in the General Vehicle Regulations, and that racing cars did not have to have suspension. Their tiny machine had a 500cc Triumph motorcycle engine mounted beside the driver's left thigh ("so that you could tune the carburettor when going flat out") and incredibly low minimal regulation bodywork with a slot for the driver's feet to stick out. Although the first engine blew up - says Bracey, "All the hot bits landed in my lap" - the car was sprinted on an impossibly low budget for a season to the despair of various scrutineers, but when the next Blue Book came out the rules had been rewritten to exclude cars without suspension, and the Tiger Shrike had reached the end of its useful life.
	Determined not to be outdone, Bracey and Samuel conceived a new miniature racing car, the Japperwock, which had a monocoque centre section, suspension of sorts and a 1-litre JAP engine to restore the power / weight ratio to its previous astronomical level. This kept them happy throughout the 1964 season, but the RAC retaliated by banning racing cars with a wheelbase of less than 6 ft - half as much again as the Japperwock's. So the tweak for 1965 was to cut the monocoque in half and insert an extra two feet of sheet aluminium to take the wheelbase up to the legal minimum.
	But Ian's ideas of the ideal Clubmen's car differed strongly various areas from Arthur Mallock's, and at the beginning of 1968 Ian rang up Dennis Jones and said "I've got fed up. Let's build a car." Between that moment and the Ibec's first race came almost exactly two years of non-stop spare-time work.
	Part of the original idea was to talk to a specialist about the aerodynamic shape of the car, and so Bracey contacted Adam Scibor-Rylski, a Pole who is Lecturer in Aerodynamics at City University in London. From their meeting came the idea of a research thesis on racing car aerodynamics, using the Bracey car as a guinea pig.
	Normal aerodynamic testing is done in a wind-tunnel, using a scale or full-size model stationary on a rigid groundboard with moving air flowing over it: in fact when the actual car is at speed over a real road the airflow is very different, especially underneath the car Scibor-Rylski's idea was to correlate wind-tunnel tests on a model with detailed action testing using the completed car, with 'instruments to record pressure readings. Bracey also interested Dunlop in ground / tyre interaction tests: these are usually done on a machine with the tyre running against a revolving drum, and once again the idea was to study the difference between the artificial conditions and the real thing.
	So from the first the car had to be designed in such a way that it could be used to take instrument readings, which dictated some early design compromises. The idea of a monocoque was abandoned, and the chassis frame was made really sturdy, of 1-inch square 18-gauge tube, to supply a rigid base for the various instruments that the car would have to carry. At the same time it would have to be a no-gimmick car, without any artificial aerodynamic aids, wings or aerofoils - Scibor-Rylski regards such devices as a blind alley, as they have no relevance to road car development. Bracey is quick to point out that the back of the Ibec has no aerodynamic significance, and is simply to strengthen the rear bodywork and round it off neatly. The suspension has to be capable of carrying the strain gauges, which supply data for the ground / tyre tests which are recorded on a tape machine carried on the car.
	Design work began 'early in 1968, when Dennis Jones laid down the rough body requirements for the car to comply with Clubmen's Formula. City University incorporated their own aerodynamic ideas and produced a scale model of the car in its final shape, and the chassis frame was built on University premises by Bracey and his helpers "because it was 'warmer." A Diva differential was used, with Diva rear uprights which were mounted upside down as their geometry turned out to be much better that way! The coil/damper units locate high on the integral roll bar, and there are the usual wishbones and twin trailing arms.
	At the front there are very large lower wishbones, and rocking upper arms which operate inboard coil/damper suspension units. These were adopted only partly for aerodynamic reasons, for the inboard springing also allows strain gauges to be more easily mounted near the wheels. The geometry incorporates 65 per cent roll compensation on camber change with static roll centre, and anti-dive but no anti-squat. The suspension is very soft, and as yet no anti-roll bars have been fitted, again because of the research programme: the interaction of roll bars would confuse the strain gauge readings. With driver aboard and a half-full fuel tank, the weight distribution is exactly 50 per cent front, 50 per cent rear. Girling competitions manager John Wood gave a lot of help over the braking system, which uses Vitesse front brakes at the front (the uprights are the ubiquitous Herald components) and Herald front brakes at the rear.
	An important design feature is the rear-mounted radiator, which allows an ideally-shaped nose. Tests with, the model in the wind tunnel showed that there was a high pressure area under the car just behind the engine, and a low pressure area at the back, so an MGC radiator was mounted in the tail, served by air carried through the propeller shaft cover. So well does the ducting work that the car runs too cool on all but the hottest days, and the radiator has to be blanked off! Another lesson learned from the wind tunnel was that the effect of a Kamm flat-backed tail is increased, or rather its drag is reduced, if hot air is filtered over the area. This, of course, the radiator does most effectively. So the rear-mounted radiator has reduced drag, by allowing a lower nose and also reducing drag at the rear; reduced lift, by relieving the high-pressure area underneath the car; allowed very effective water cooling; and also kept the final drive cool, for the differential casing is in the air ducting. The actual size and shape of the front air intake was carefully calculated, for as well as serving the oil cooler the air is channelled along the hollow bulbous sides of the car and out over the rear wheels. The underneath of the car is fully enclosed.
	The bodywork, beautifully executed in neatly fitting aluminium panels, was made by Ernie Wakefield of Byfleet, who used to make the bodywork for Grand Prix cars before the days of fibreglass. Ernie preferred not to work from drawings, so a rough wire framework of the desired body shape was stretched over one half of the car and he worked from that.
	A year in the designing and research, a year in the actual building, and by February 1970 the Ibec was finished. The first five races were plagued by non-stop troubles with the Felday engine, and finally the Ibec team stopped trying with that unit and ordered a new downdraught Holbay clubmen's engine. With the car in this form Bracey did seven races; the first outing, at Brands, was that heroic Mansfield/Goss/Bracey battle, with 1 1/2 car lengths covering the Dino, the Lotus 7X and the Ibec at the flag. In the next race, at Castle Combe, Goss won and Bracey battled with the Mansfield Dino, driven this time by Jeremy Lord, and missed second place by 0.4 sec. At Silverstone the Ihec lay second until the front dampers seized up and the resulting understeering moments all round the course dropped it to fourth.
	At Lydden Hill, after being fastest in practice, Bracey made a driving error and had an argument with a marshal's post, breaking two ribs but happily doing very little damage to the Ibec. At Oulton it was second place again until the big bulge that covers the carburettors came adrift, and a pit stop was necessary to remove it, although the Ibec came through to fourth by the end. At Castle Combe Ian was second to Goss again, and at season's end at Brands Hatch he started with a l0-secs penalty after missing practice and came through to finish third.
	Over the winter several new modifications have been made to the car in the light of the first season's experience. Most notable change concerns the engine, for the downdraught engine has been replaced by one of Holbay's latest 160 bhp crossflow' clubmen's units, which will also allow the very un-aerodynamic power bulge in the bonnet to be deleted.
	Ian very kindly put the car at my disposal recently for the purposes of a track test, but it turned out to be one of those projects that seems to be doomed from the start. The first time we took the car to Brands Hatch gale force winds and stormy rain lashed the circuit, so we decided to save the car for another day. The one we chose was so foggy that from Druids you couldn't see half way to Bottom Bend, so it was a case of waiting for the fog to clear. In mid-afternoon the fog did lift sufficiently for me to take the car out, whereupon the Ibec developed an unprecedented and peculiarly insoluble throttle linkage problem which twice sent me into Druids at ever increasing speed with no alternative but to spin the car away from the rapidly approaching marshal's post.
	But in the few laps that I did do in the car I was able to find that the handling was very predictable and the car seemed excellently balanced; despite its soft suspension and lack of anti-roll bar's it felt steady as a rock, and perhaps because of its softness it hung on particularly well over the Clearways bumps. But what really impressed me was how well thought out and beautifully made the car was, down to the smallest details.
	It is projects like the Ibec which help to make British amateur motor racing the fascinating sport that it is, and modern Clubmen's Formula one of its best classes. We look forward to hearing the results of the various research programmes being carried out with the Ibec - and to seeing its ideas working in practice in this year's Clubmen's Formula races.