That's the trouble with Voyargers you've got a a large diesel engine generator and radiators plus air conditioning etc. in a sealed unit under the train where it gets no cooling.
If you want 10 or over hp per ton (diesel) stick it in two power cars with a set of Mark 3 s or better still an 87 and mark threes with a DVT don't stick it underneath the coach. Unfortunately the 87 solution reuires a lot more wires to slung.
Anyone remember that when Virgin won the XC franchise their franchise proposal was loco + coaches. If I recall, all the other (losing) propositions were DMUs. But sometime in the next year it became the multiple unit proposition which we now have.
