There was 3 different variations of the origial Speed 12, the very first was called the 7/12 for 7 liter V12. Then it was renamed the Speed 12, the 7/12 but it only had 660Bhp (I use only when comparing it to the other two).The car was then renamed the Speed 12 and it was tuned to around 800Bhp. The second Speed 12 had a wing on the back like the one in GT2 and 800+ Bhp, the most recent one the Cerbera Speed 12 has more than 960Bhp, t he 800Bhp figure was taken when TVR were tesing the car on a dyno, it reached a certain Rpm and it's torque snapped one of the holding straps, it had a few thousand Rpm's left but it reading at that point was 800Bhp, TVR decided not to test it again.
Peter Wheeler did drive a Cerbera Speed 12 home once and that was what made him not put it into production, he said it was undrivable on public roads, it was ok on a test track for a FR car with that much power and no ABS or TCS but not on bumpy roads. Only 5 Cerbera Speed 12's were built one has been chopped up and is in a museum alongside another fully built one, two others are resting in TVR's garages and one was sold to a private buyer for £155,000 in red.