What I am trying out is a large trunk which brings air from beside the radiator to an inch or so in front of the filter. It might be wishful thinking but if for example I place it behind the fan it certainly blasts air out. thanks again all of you. Meabh.
Isn't the potential problem with that the likelihood of creating a very turbulent air flow- and also the length of the 'runner' perhaps also moving the BHP curve down the rev band? Just a thought

G