COSWORTH GB

COSWORTH GB

IN THE FIRST OF A NEW SERIES THAT ASSESSES INTRIGUING MIGHT-HAVE-BEENS EV THE RACING ENGINE ARENA, KEITH HOWARD ANALYSES THE TURBO V6 THAT HAD THE UNENVIABLE TASK OF FOLLOWING IN THE TYRE TRACKS OF COS WORTH’S DFV, F1’S MOST SUCCESSFUL POWER UNIT F ormula One’s turbo era was not greeted with universal enthusiasm. And its most vocal critic, Cosworth’s Keith Duckworth, hardly rated as a disinterested party: as designer of the previously ubiquitous DFV, he had good reason not to welcome this

new broom sweeping clean. But his objections were deep-rooted and sincerely held: he considered the use of a turbocharger, a second engine, to be against the spirit, arguably even the letter, of the FIA’s regulations. Like a law-abiding citizen prosecuted under some obscure 17th Century

statute, he was affronted that a rule originally intended to allow engine makers to supercharge their existing 1.5-litre power plants as a means of easing F 1 ‘s transition to a 3-litre formula in 1966 had been cynically exploited, first by Renault, then by others, to turn grand prix racing of the late 70s and early ’80s on its head.

Nobody was listening, though, and by the time the first turbo-powered drivers’ champion, Nelson Piquet, was crowned in 1983 it was already abundantly clear that to win future Fl championships you would need a blower. Funded again by Ford, Cosworth therefore bit the bullet, swallowed its pride, and set about beating the forcedinduction lobby at its own game.

Plan A, had it come off, would have rewritten F! history in spectacular fashion. To annihilate the opposition, Duckworth planned a wide-angle turbo compound V6 with the blower nestling in the vee, and recruited experts from RollsRoyce aero engines to help conceive it. Unlike a conventional turbocharged engine, a turbo compound design connects an exhaust turbine to the crankshaft to increase engine output directly rather than indirectly via forced induction. Using this technology. Duckworth reckoned, Cosworth could create an engine twice as powerful as anything

else on the grid. Development work began in 1984 on a fourcylinder proof-of-concept cobbled together from BDA parts. Despite some early and initially puzzling crankshaft failures, caught on camera as part of a Patrick Uden documentary, the prototype which included a miniature, electronically controlled CVT drive between turbine and crank showed sufficient promise for Duckworth to approach the FIA for a ruling on the concept’s legality. Admitting there was

nothing in the regulations to preclude it, the sport’s ruling body nevertheless declared it would ban turbo compounding when the engine won its first race. Far from being downcast, Duckworth rather liked this idea. Being banned for comprehensively outthinking and outperforming other Fl engine makers seemed to him the ultimate accolade. But sponsor Ford saw things differently. Dearborn was in this for the marketing benefit, and the prospect of peremptory outlawing the minute success was achieved

did not appeal. And so Plan B: the same wide-angle, 120-degree V6 but conventionally turbocharged. Work began

on the engine in 1985, with Geoff Goddard as chief designer. Ford called it the TEC turbocharged engine Cosworth while internally at Northampton it was known as the GB. The compact package measured about 450mm long by 510mm high and weighed under 200kg. Having established that the FIA didn’t like turbo compounding, Duckworth sought to clarify the position regarding so-called ‘rocket’ fuels. Ever since BMW had solved its detonation problems with the Wrotershall fuel in 1983, the role of the fuel chemists had become increasingly significant in determining engine performance. The FIA assured Duckworth that the use of special fuels would be stamped on early in the 1986 season, so Cosworth mindful of Ford’s reputation designed the GB to run on regulation ‘pump fuel’. Thus the engine began life with a compression ratio of 6.5:1 and a peak power output of around 750bhp : nowhere near enough to make

an impression against the likes of Honda and Renault. Ford insisted on its Motorola EEC-IV engine management system being used, a decision which significantly delayed the engine’s early development The original plan had been to run it for the first time immediately after the 1985 Australian GP, but in the event it first turned a wheel in the back of the Beatrice-sponsored FORCE car at a snowy Boreham early in 1986. Goddard recalls the first abortive attempt to start the engine with the EEC-IV controller failing miserably, prompting accusations by Ford engineers that mistakes in the engine design were the cause. Cosworth staff then produced an alternative ECU that, in Blue Peter tradition, they’d

prepared earlier. The engine fired first time.

Once it became apparent that the FIA would not tackle rocket fuels, Cosworth sourced its own from BP. By the end of the 1986 season, using a super-high compression engine with a CR of 9.5:1, Alan Jones was able, for a while, to match the searing pace of race leader Ayrton Senna in Austria, despite starting from 16th on the grid. Next season now with a 4-bar boost limit and Mobil the GB found itself in the back of Benetton’s B187, a better car but also short on development. By the season’s end the team had amassed 28 points as opposed to the FORCE’s paltry six the previous year. But fifth in the constructor’s championship, 109 points adrift of Williams-Honda, was not much to shout about Ford made the decision to go normally aspirated for the

1988 transitional season, and so the TEC project reached an abrupt end.

Although the GB is commonly dismissed as a latecomer also-ran, Goddard points to contrary evidence. By 1987, it produced a highly competitive 1000bhp or so and was sufficiently bomb-proof to run 10001cm between rebuilds. And lurking in the FIA’s race data are intriguing hints to its true status. Most spectacular was Teo Fabi’s run at Imola. Having had his front wing nerfed in a first-corner incident, he spun the ill-handling Benetton on lap 18 and limped to the pits. By lap 33 he was 74sec behind the leader Nigel Mansell, when suddenly the red mist descended and he began to reel in the Williams at 1.5sec a lap. By lap 52, when a suspension wishbone, damaged in the collision, finally gave way, he had reduced the gap by almost half a minute with seven laps remaining. 111 Thanks to the Donington Collection (01332 811027)