21-03-2014, 05:56 PM
Two brand new engines with the same mileage would make the same figure give or take the tolerance of the dyno, temperature deviations,tyre pressure etc etc, but the basic figure should be very close, manufacturing tolerances wouldn't give a lot of room for the engines to be different, I would expect within less than +/- 0.5 BHP of each other if the dyno was decent. I doubt they would give dead on 90BHP straight out the factory, that's just a rounded figure they sell the car with.
For jet engines we apply a magnitude of corrections when measuring thrust upon a test bed, we then test other test beds with a 'control' engine to check the performance of the cell and that the result is the same. The result is actually the figure after all corrections as you're never going to have the exact temperature that your control baseline runs from (usually 15C 288K). I think dynos make some form of correction relative to temperature but I'm not 100% on that....?
For jet engines we apply a magnitude of corrections when measuring thrust upon a test bed, we then test other test beds with a 'control' engine to check the performance of the cell and that the result is the same. The result is actually the figure after all corrections as you're never going to have the exact temperature that your control baseline runs from (usually 15C 288K). I think dynos make some form of correction relative to temperature but I'm not 100% on that....?