Post by Töuge-MR on Feb 7, 2005 23:43:13 GMT -5
Covini's six wheeled sportscar
Covini is a name which is not well known in automotive circles outside of Italy - that's almost certain to change thanks to the small company's latest design - a six wheel sports car along similar engineering lines to the famous Tyrrell P34 Formula One racing car of the mid-seventies.
The six wheeled design offers many advantages over a conventional design as it offers more traction for cornering and braking and minimises the risks associated with tyre punctures and aquaplaning.
The Tyrell P34
The Tyrrell P34 is without doubt the most recognisable car in the history of world motor sport - it had a few brief moments of glory and was gone thanks to a key tyre manufacturer changing allegiances. In recent years the advent of the FIA Thoroughbred Grand Prix World Championship, the distinctive Derek Gardner designed P34 has once again greeted the chequered flag, and on a much more regular basis.
The only six wheeler ever to start (much less win) a Grand Prix, the P34 was retired from action largely due to the lack of a suitable tyre partner.
The exact circumstance of Goodyear's split with Tyrrell might never be known, but Formula 1 is an expensive exercise for tyre manufacturers at the best of times and the need to develop an entirely different tyre just for the P34 did not seem to make economic sense when it either doubled the entire development budget, or halved the effectiveness of the development for the company's conventional formula one tyres. Though the tyre war was not nearly as fierce three decades ago in F1, it still saw tyre manufacturers take hundreds of tyre compound and carcass variations to each Grand Prix. And there was little upside for Goodyear - it was unlikely that six wheel cars would ever reach mass numbers.
While Goodyear was not convinced, Tyrrell's efforts had impressed some of the other teams sufficiently to create their own versions of the four wheel front end. McLaren and March both had complete six-wheel cars ready to go when Tyrrell pulled the plug on the six wheeled development, so at least some serious brains thought the idea had merit.
That the car won Grands Prix (with a famous 1-2 finish in Sweden in 1976) bears testimony to the design - the decision by GoodYear to turn its attention to another tyre development opportunity may have prematurely killed a fundamentally sound engineering solution.
Idea is three decades in incubation
Covini conceived the original idea for his car in 1974 and made provision in his design for 10 inches front wheels because there were no low profile tyres available at the time. The project was ditched in favour of another design endeavour (the Soleado prototype), and lay dormant until the 80s when hydro-pneumatic suspension for the four front wheels was devised to optimise weight distribution under various loading conditions. High development costs and other contingencies forced the project to be delayed again. As the emphasis in road going automotive design shifted to passive and active safety during the nineties, Covini again began work on the six-wheeler and this time around, he found the backing required from larger companies to finance its development.
WHY SIX WHEELS?
The arguments for four front wheels are many - Tyrrell's aim with the P34 front-end layout was intended to '... minimize induced drag by reducing lift at the front and to turn that gain into the ability to enter and leave corners faster.'
In a roadgoing sense, the passive safety afforded by two front wheels at each corner means a front tyre puncture will not cause the vehicle to lose control (thanks to the other wheel next to it).
Then there's the additional stopping power afforded by four front discs and four tyre footprints to transmit the force - although the individual area of each tyre footprint is smaller than that of a traditional tyre, the total area is greater.
The designers also claim there is less risk of aquaplaning because the two foremost wheels clear the water for the ones behind them and allow better road adhesion.
Comfort is another consideration - less unsprung weight at each wheel allows the suspension to control wheel movement better and the overall ride benefits from more evenly distributed reaction forces in the suspension.
The drop in the individual unsprung weight of each wheel also offers much better grip and better directional stability - with a well-matched set of tyres, a six-wheeler can be expected to have higher cornering speeds than a four wheeler.
In the case of Formula 1, where aerodynamic efficiency is critical, the lower profile of the front wheels offers a theoretical advantage but whether that advantage was ever demonstrated with the Tyrrell P34 is arguable. Aerodynamic focus has shifted in recent decades to how a car leaves the air it passes through rather than the initial penetration of the air it is pushing out of the way. The high profile of the rear wheels of a Formula One car simply shifted the aerodynamic problems of the P34 rather than reducing them and the high-creativity and low-budget Tyrrell concern did not have the development resources available to work through all the new issues its design raised. Covini's collaborators in the project include DAEWOO (technological research on prototypes), BOSCH (electronic and braking system), BREMBO (brake system), MOMO (airbag and new technology), PIRELLI (special tyres and research), ANTERA (special ultra-light alloy wheels) and POLITECNICO DI MILANO (optimization of the chassis set-up).
For a road-going six-wheeler though, there is no aerodynamic advantage and there's additional cost and mechanical complexity, none of which matter on a very expensive, low-volume supercar such as the Covini.
The P34 experienced a host of development issues which technology has since solved.
The P34 had trouble with cooling the rear-front-brakes - materials technology has solved that problem.
The P34 had trouble when front wheels locked, because a front-front lock-up effectively lengthened the wheelbase and slowed the steering whereas a rear-front lock-up shortened the chassis and quickened the steering. The development of anti-lock braking technologies in the subsequent decades can ensure that all four front wheels retain optimum traction.
Covini's car certainly looks the business - in the go-department it is powered by an Audi 4.2 litre V8 motor (283.4 kw / 380 bhp @ 6400 rpm) which powers it to a top speed of 300 kmh.
No price has yet been set for the Covini, but as the saying goes, 'if you have to ask the price on this car, you can't afford it.'
SPECIAL THANKS - thanks to FIA Thoroughbred Grand Prix World Championship for the photos of the P34 Tyrrell. The TGP F1 championship series will be the feature of an upcoming article - check out the series web site where you can follow what is essentially vintage motorsport in ex-F1 cars and if you have a lazy $500K don't miss their used car section which is comprised of largely ex-F1 racecars.
From: www.gizmag.com/go/2754/
Covini is a name which is not well known in automotive circles outside of Italy - that's almost certain to change thanks to the small company's latest design - a six wheel sports car along similar engineering lines to the famous Tyrrell P34 Formula One racing car of the mid-seventies.
The six wheeled design offers many advantages over a conventional design as it offers more traction for cornering and braking and minimises the risks associated with tyre punctures and aquaplaning.
The Tyrell P34
The Tyrrell P34 is without doubt the most recognisable car in the history of world motor sport - it had a few brief moments of glory and was gone thanks to a key tyre manufacturer changing allegiances. In recent years the advent of the FIA Thoroughbred Grand Prix World Championship, the distinctive Derek Gardner designed P34 has once again greeted the chequered flag, and on a much more regular basis.
The only six wheeler ever to start (much less win) a Grand Prix, the P34 was retired from action largely due to the lack of a suitable tyre partner.
The exact circumstance of Goodyear's split with Tyrrell might never be known, but Formula 1 is an expensive exercise for tyre manufacturers at the best of times and the need to develop an entirely different tyre just for the P34 did not seem to make economic sense when it either doubled the entire development budget, or halved the effectiveness of the development for the company's conventional formula one tyres. Though the tyre war was not nearly as fierce three decades ago in F1, it still saw tyre manufacturers take hundreds of tyre compound and carcass variations to each Grand Prix. And there was little upside for Goodyear - it was unlikely that six wheel cars would ever reach mass numbers.
While Goodyear was not convinced, Tyrrell's efforts had impressed some of the other teams sufficiently to create their own versions of the four wheel front end. McLaren and March both had complete six-wheel cars ready to go when Tyrrell pulled the plug on the six wheeled development, so at least some serious brains thought the idea had merit.
That the car won Grands Prix (with a famous 1-2 finish in Sweden in 1976) bears testimony to the design - the decision by GoodYear to turn its attention to another tyre development opportunity may have prematurely killed a fundamentally sound engineering solution.
Idea is three decades in incubation
Covini conceived the original idea for his car in 1974 and made provision in his design for 10 inches front wheels because there were no low profile tyres available at the time. The project was ditched in favour of another design endeavour (the Soleado prototype), and lay dormant until the 80s when hydro-pneumatic suspension for the four front wheels was devised to optimise weight distribution under various loading conditions. High development costs and other contingencies forced the project to be delayed again. As the emphasis in road going automotive design shifted to passive and active safety during the nineties, Covini again began work on the six-wheeler and this time around, he found the backing required from larger companies to finance its development.
WHY SIX WHEELS?
The arguments for four front wheels are many - Tyrrell's aim with the P34 front-end layout was intended to '... minimize induced drag by reducing lift at the front and to turn that gain into the ability to enter and leave corners faster.'
In a roadgoing sense, the passive safety afforded by two front wheels at each corner means a front tyre puncture will not cause the vehicle to lose control (thanks to the other wheel next to it).
Then there's the additional stopping power afforded by four front discs and four tyre footprints to transmit the force - although the individual area of each tyre footprint is smaller than that of a traditional tyre, the total area is greater.
The designers also claim there is less risk of aquaplaning because the two foremost wheels clear the water for the ones behind them and allow better road adhesion.
Comfort is another consideration - less unsprung weight at each wheel allows the suspension to control wheel movement better and the overall ride benefits from more evenly distributed reaction forces in the suspension.
The drop in the individual unsprung weight of each wheel also offers much better grip and better directional stability - with a well-matched set of tyres, a six-wheeler can be expected to have higher cornering speeds than a four wheeler.
In the case of Formula 1, where aerodynamic efficiency is critical, the lower profile of the front wheels offers a theoretical advantage but whether that advantage was ever demonstrated with the Tyrrell P34 is arguable. Aerodynamic focus has shifted in recent decades to how a car leaves the air it passes through rather than the initial penetration of the air it is pushing out of the way. The high profile of the rear wheels of a Formula One car simply shifted the aerodynamic problems of the P34 rather than reducing them and the high-creativity and low-budget Tyrrell concern did not have the development resources available to work through all the new issues its design raised. Covini's collaborators in the project include DAEWOO (technological research on prototypes), BOSCH (electronic and braking system), BREMBO (brake system), MOMO (airbag and new technology), PIRELLI (special tyres and research), ANTERA (special ultra-light alloy wheels) and POLITECNICO DI MILANO (optimization of the chassis set-up).
For a road-going six-wheeler though, there is no aerodynamic advantage and there's additional cost and mechanical complexity, none of which matter on a very expensive, low-volume supercar such as the Covini.
The P34 experienced a host of development issues which technology has since solved.
The P34 had trouble with cooling the rear-front-brakes - materials technology has solved that problem.
The P34 had trouble when front wheels locked, because a front-front lock-up effectively lengthened the wheelbase and slowed the steering whereas a rear-front lock-up shortened the chassis and quickened the steering. The development of anti-lock braking technologies in the subsequent decades can ensure that all four front wheels retain optimum traction.
Covini's car certainly looks the business - in the go-department it is powered by an Audi 4.2 litre V8 motor (283.4 kw / 380 bhp @ 6400 rpm) which powers it to a top speed of 300 kmh.
No price has yet been set for the Covini, but as the saying goes, 'if you have to ask the price on this car, you can't afford it.'
SPECIAL THANKS - thanks to FIA Thoroughbred Grand Prix World Championship for the photos of the P34 Tyrrell. The TGP F1 championship series will be the feature of an upcoming article - check out the series web site where you can follow what is essentially vintage motorsport in ex-F1 cars and if you have a lazy $500K don't miss their used car section which is comprised of largely ex-F1 racecars.
From: www.gizmag.com/go/2754/
