Max Bobnar, an authorized Automobili Lamborghini SpA dealer for Switzerland had his personal Countach LP5000 S modified by Franz Albert, an Austria based engineer who installed two small turbo's on the 5.0 Liter V-12 engine.
These turbo pumped up the horsepower to a healthy 520 Bhp at 6500 rpm, with this engine installed the Countach LP5000 S Twin Turbo managed to reach 100 Km/u (60 Mph) in 4.8 seconds, instead of 5.9 seconds for a 'standard' 5-Liter unit. Top speed for this special Countach isn't recorded, but Max Bobnar drove it at a sustained speed of 290 Km/h (180 Mph) with still room for more, he didn't push it all the way because he didn't know if the standard suspension could cope with speeds above 300 Km/h.
The current whereabouts of this car are unknown to me, if anyone has any idea, please let me know.
There seems to be another turbo charged Countach out there too, read about it on Teamspeed.com
Covert Tuning Dynamics claim to have built a 2000 hp rear wheel drive Raging Bull based on the already impressive Lamborghini Murcielago LP670-4 Super Veloce.
(added on September 19. 2012)
ADV.1 Wheels on a stunning looking matte black first series Gallardo Superleggera with the added bonus of a twin turbo conversion.
(added on January 13. 2013)
After installing a twin turbo system on the new Lamborghini Aventador the V12 delivers no less than 1200 hp.
(added on June 5. 2012)
An impressive Lamborghini Gallardo fitted with a Heffner Twin Turbo kit producing 1,500 hp wearing the IMSA GTV Wide Body kit.
(added on October 26. 2013)
After the Heffner TT conversion wasn't enough the owner turned to ZR Auto to increase the power output to 1,470.
(added on August 8. 2012)