Fundamental to Invicta’s desire to deliver no-compromise performance in terms of handling balance and sheer speed, was the decision to mount the S1’s engine and gearbox well back in the chassis and the 100-litre fuel tank transversely between the rear wheels, to achieve close to the ideal 50/50 front/rear weight distribution.
Fitted with Invicta’s own air-intake and exhaust systems, the 4.6-litre engine powering the S1 is supplied by Ford’s Special Vehicle Team (SVT) in America. The all-aluminium, 32-valve V8 weighs just 240 kilos and produces 320 bhp and 300 lb ft of torque. Light, smooth-revving and ultra-reliable, this engine promises to deliver stunning acceleration in the 1100 kg S1 – which is more than 300 kg lighter than the Ford Mustang Cobra which uses the same engine in the USA. Each engine is hand-built at Ford’s SVT facility and carries a plaque signed by the two technicians responsible for its assembly.
The completely flat floor of the S1 and the rising rear undertray promise to give low-drag and generate downforce. Calculations predict that the S1 will accelerate from 0-to-60 mph in five seconds, to 100 mph in under 11 seconds, and will comfortably exceed 170 mph when road conditions permit. The combination of high power, massive torque and low weight is a recipe for good fuel economy and Invicta calculates that the S1 will return 25 mpg overall, giving a comfortable 500 mile range from the 21.9 gallon (100-litre) fuel tank.
Transmission & LSD
The five-speed manual gearbox fitted to the S1 is a tough Borg-Warner T45 unit – as used in the Ford Mustang Cobra. Robust and reliable, the T45 is mounted so far back in the S1 that the gear lever goes straight into the ’box top for a very direct, positive selector action. Both six-speed manual and four-speed automatic transmissions are available as optional extras.
Drive from the front-mounted engine travels via the gearbox to the rear wheels through an Australian BTR hydratak viscous -coupling limited-slip differential.
Suspension & Steering
Building on the major attributes of a stiff body/chassis structure and balanced weight distribution, the Invicta S1 suspension adopts a tried and proven classic layout and employs a pair of unequal length, double wishbones front and rear with anti-roll bars. Designed and produced in-house, the wishbones carry compact uprights developed jointly with AP and manufactured by Invicta. Specially developed suspension bushes from Powerflex ensure precise mounting of the wishbones, with sufficient insulation from road shocks to maintain good ride comfort.
The S1 comes with coil springs and dampers tuned to give the best possible blend of ride and handling. The dampers are easily adjustable for using the car on track days. Customers wishing to exploit the Invicta S1’s undoubted race car potential, will also find that camber, castor and anti-roll bar settings are all adjustable over a wide range.
The power steering is a Lucas system requiring three turns of the steering wheel lock-to-lock.
continues | Part Three