BAC reveals lighter, more powerful Mono R

British supercar-maker BAC has unwrapped its Mono R at the Goodwood Festival of Speed that promises to be the fastest, most extreme model it's ever made.

Developed to offer owners even higher level of performance than the standard Mono, the changes over the regular single-seater are surprisingly comprehensive.

The first is the Mono R pumps out an extra 26kW from its naturally-aspirated 2.5-litre four-cylinder engine that was sourced from Ford but honed by British tuner Mountune.

Combined with a new titanium exhaust, now, total power is 250kW which doesn't sound all that impressive until you realise the new car 25kg lighter than the old one, tipping the scales at a featherweight 555kg.

It's not just a little extra muscle that makes the Mono R special, BAC says it features a completely new body that introduces a new shark nose front and centrally-mounted LED lamps.

The body itself is also said to be slimmer and re-profiled for greater aerodynamic efficiency.

You'll also notice the prominent single seat race car's side-mounted pod intake that introduces a ram-air affect for more power.

Other changes include slimmer front archers and the introduction of a large rear spoiler that's combined with a narrower tail and new LED lamps.

Beneath the skin there's also new blades that divert and manage airflow for more downforce and less drag.

Helping cope with the extra performance the Mono R gets chassis changes, that include new Ohlin two-way adjustable dampers that sees it ride around 20mm lower than the standard car.

Reigning in the extra performance is a set of lighter AP Racing brakes.

Inside, there's a lighter steering wheel and yet more carbon-fibre side panels.

Against the clock, thanks to the extra power and kilo-cutting, the Mono R can hit 60mph (97km/h) in just 2.5 seconds.

Top speed, meanwhile, is 274km/h.

BAC says it will make just 30 Mono Rs with the entire run of cars already sold out, despite each car being priced from a sobering £190,950 ($A340,000).