Originally Posted by
LeonOfTheDead
about that, I would say the stress could be still relevant due to thicker components in a diesel engine, therefore higher masses even for rotating components. still it's the rotating speed the main issue, and I doubt the mass is so much higher to balance the effect.
the Audi engine should be heavier than the Judd to equal the safety due to the higher stress generated by the diesel combustion process, so even considering an equal stress but an higher weight the torque is likely going to be give the Audi a better overall performance, regardless of 20 hp gap in power, if that's the case.
I have no doubt that the Judd is lighter, but I think as you said the overall benefit is probably bias toward the Audi just because of the extra flexibility afforded by the Audi. Though I don't think the Audi is as heavy as one might imagined, since from the very beginning of their diesel program they are claiming the specified mass per cylinder the 5.5l V12 is the same as the R8's 3.6l V8. And that the V10 is the same as the V12.....mind you, the Judd still saves on the lack of plumbing over the twin-turbo diesel....
The higher and likely much flatter torque curve also translate to probably better power in ALL rpm range, even if the Judd might make the same peak power. Remember that the torque characteristic was flexible enough that they were able to eliminate a gear...
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