My beast went on the rollers too, and got a respectable 478bhp, but strangly only 400lb/ft torque. The 478bhp was a little less than I was realisticly hoping for. A couple of owners back, in the end of 2005 it achieved 536bhp somewhere, the previous owner had around 470 on the same type of rollers in 2008, then a couple of weeks later tried again on the same rollers and got 502 (and these were the same type of roller used by Paramount) My car was serviced by grizz 3500 miles ago.
David Koulakis had his car on the rollers before mine and they guys seemed to struggle a bit with something with his runs so I don't know whether there are any missing horses with his and mine because of the rollers or not. I don't have any concerns form a driving point of view though but don't really have much to compare it too.
A few pics for you








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