Performance Car's figures were 0-60MPH in 5.2 seconds, and 172MPH top speed - faster at the time than a Ferrari Testarossa, which was Ferrari's quickest model! But I don't doubt that quite a few did at least 180.
The car was based on the Vauxhall Carlton GSI3000 24V (or Opel Omega equivalent), and Vauxhall basically passed complete cars to Lotus to be "breathed on".
Lotus then:
bored the engine out to 3.6 litres (377BHP and 485lb/ft of torque if I remember rightly)
fitted twin turbos and a Chargecooler
fitted a Chevy Corvette ZR-1 6 six speed gearbox (which was geared to -get this - 44MPH per 1000RPM in top!)
fitted a special bodykit and resprayed the car in only 1 colour - "Empire Green" (but it looks black)
fitted a big exhaust
fitted their own wheels
transformed the handling
fitted a bespoke interior and dash
At the time (around 1991-94) they cost £48,000. Now you can get them for £10K+, and a really good one for £20K. But if you think sourcing parts for Elans is tricky and expensive, then these are in a whole new league.
The LEC equivalent for the Lotus Carlton is
http://www.autobahnstormers.co.uk/ and there are some great pics in the gallery.
They displayed 3 or 4 at Donington this year when we were there, and they remain my all-time-street-sleeper-supercar.