0-60 mph in 2.9 seconds, over 240 mph top speed from the car with a power output yet unknown. And why is that you wonder?! Because it broke the shaft of every dyno it was tested on...
The TVR Cerbera Speed 12 was an ultra high performance concept vehicle designed by TVR in 1997. Based in part on the TVR hardware at that time, the vehicle was intended to be both the world’s fastest road car and the basis for a GT1 class Le Mans racer.
The vehicle’s engine, displacing 472 cui and having twelve cylinders, was reportedly capable of producing nearly 1000 horsepower, although an exact measurement was never made. It’s performance was said to be astonishing, and by all calculations it would have been capable of hitting sixty miles per hour in the low-three second range and power to well over 240 per hour.
The first concepts shown were based on the in-development FIA GT1 class race-car that was current at that time. The racer was restricted to a more modest 660 bhp but the weight was kept at roughly 1000 kilograms. The road car would weigh the same, but without the restrictors the power was greatly increased. It also had a specially built 6 speed transmission and clutch. The engine consisted of two TVR AJP6 engines mated together onto a single crank.
In 1998 the car was named the TVR Speed 12. The GT1 racer was almost ready to go, TVR wanted to race at Le Mans, but unfortunately that never happened. The Speed 12 GTS managed to compete in a few races in the FIA GT championship in the GT1 class, though sudden rule changes and the demise of the GT1 class suddenly rendered the Speed 12’s existence obsolete. In order to not let all that work go to waste TVR immediately set about creating the road-going Speed 12, although the project would not be completed for another year.
Forward to the year 2000, TVR have revealed the TVR Cerbera Speed 12. Like its predecessor, the true power output of the engine was never officially revealed, although, the original engine (which produced 800bhp) was employed yet again. The weight was kept down to 1000 kilograms and TVR reminded people that they were making a car that they thought would beat the McLaren F1 with the words ’over 240 miles per hour’ mentioned a few times. The new car would also be built in parallel with a new race car, although they had to opt for GT2 as there was no longer a GT1 class. The new race car managed to run for a few seasons in the British GT championship and had some success, winning a few races. It did however have problems with reliability which often led to the car retiring frequently. Meanwhile, the road car was almost ready and TVR had taken a good number of orders and deposits for it. With a price of £188,000, it certainly wasn’t cheap; it would be the most expensive TVR in history.
Peter Wheeler, who owned TVR during the car’s development, once declared that TVR had tried to record the car’s power on an engine dyno. The dyno was rated at 1000 bhp but the test resulted in the dyno’s input shaft being broken. To get an approximate figure TVR engineers tested the engine again but they tested each bank individually; the result was 480 bhp per bank. This would suggest a rating of 960 bhp in total. Although this didn’t provide an exact figure, it was far closer than the original estimates were. The real figure is still unknown. This was the beginning of the end for the Speed 12’s production hopes. Peter Wheeler drove one of the finished prototypes home and he concluded that the car was unusable on the road. It was simply too powerful. Wheeler was no newcomer to high performance cars, he even raced in the TVR Tuscan challenge for a number of seasons.
The deposits were returned, the production plans were cancelled, the remaining prototypes were carted around to various car shows and one by one they were taken apart and used as spares for the Speed 12 race cars still racing in the British GT championship. But that wasn’t the end of the Speed 12. In August 2003 TVR placed an advert in Auto Trader for none other than the TVR Cerbera Speed 12, registered W112 BHG. What TVR planned to do was to rebuild one of the prototypes and sell it on to an enthusiast. Buying the car wasn’t as simple as ringing up and saying "I’d like to buy your car please". You had to go and meet Wheeler who would then make sure you were the right sort of person for the car, and then he would consider you as a potential buyer. The deal was done and the Speed 12 was rebuilt and handed over to its new owner. Since the original bodywork had been destroyed, TVR had to use a remaining shell from one of the GT racers which was really no bad thing. With the increased downforce the car would be even faster round a track than before. On top of that TVR did some more work on the engine and the ECU. The car even featured in the May 2005 edition of Evo Magazine in which it was described as "awesome" and "terrifyingly quick". The car still hasn’t been fully performance tested, but the power is still estimated at somewhere over 960 bhp depending on the cams fitted and the ECU mapping.
International GT rules suggested a flat floor and a tubular steel roll cage and so the primary chassis of the car consists of a T45 steel tubular safety cell which is integrally braced by the flat aluminum honeycomb floor and bulkheads.
This hybrid construction followed both the racing rules and allowed for the car to be quite simple to assemble. The front bulkhead was immediately behind the engine whilst the rear one lies directly ahead of the rear wheels. This allowed the exhausts to exit cleanly away from the engine and then turn ahead of the foot-well to run down the sills, and the driver to sit as far rearward as possible.
Body & chassis
The bodywork was all manufactured in house out of carbon fiber pre-preg composite with a mixture of Nomex and Kevlar reinforcement, the overall style being that of a "Cerbera on steroids"
The entire front and rear were one piece mouldings for quick and easy access whilst the cabin section was bonded to the honeycomb bulkheads and sides to form the sealed passenger compartment.
Particular attention was paid to the air flow with the intention of minimizing under bonnet turbulence and cooling, both for the engine and brakes and also for the driver.
The front screen contained a heating element for elegant demisting whilst rear vision is perhaps described at best as "adequate", given the imposing presence of the rear wing.
Engine & transmission
The engine was fitted by removing the entire front end of the car, without the necessity of disconnecting any oil or water pipes. The outermost ends of the sub-frames were terminated in aerospace alloy billet bulkheads that fulfilled both structural and practical roles.
At the front side two bulkheads back to back, machined from solid plates, form a void that is the oil dry sump tank; providing all the mountings for the front suspension and steering rack and physically connected the open sub-frame tubes.
At the rear a similar bulkhead machined from solid plate seals the rear of the differential housing and provides mountings for the rear suspension. The differential housing provides a structural load path between the rear subframe and the cabin section via a fabricated casing that also locates the rear lower wishbones.
The suspension was composed of classic double wishbones all round, with coil over gas dampers operated by pushrods and with rising rate anti-roll bars front and rear. The centre lock magnesium wheels ran on steel hubs within exquisitely fabricated aerospace steel vaned uprights to allow cooling air to reach the massive (15") brake discs and calipers. At the rear the driveshaft CV joints were integrated within the hub/bearing assembly. All of the suspension joints pivoted on spherical bearings.