Hi Chris
Couple of questions and thoughts,
The firing sequence on the volvo engine is uneven as it seems they are grouped in twos. Therefore the way is to use a bi-turbo setup with a seperate inlet and carburation system per bank. As it looks as though from memory that each bank fires alternately, this would then provide an even boost pressure.
When turbos are factory produced (not Deloreans) the compression is lower than a conventionally aspirated engine, to take into account the boost pressure. Are the deloreans which have a turbo fitted running different pistons and con rods? to decrease the compression or is the boost pressure set lower to stop the engine meeting its maker?
The alternative could be to just to fit NOS, apparently this will produce from 50 bhp upwards depending on jets.
Let me know you comments when you have minute, keep cleaning the Paris car.
Regards
Kevin #5959