Thank you for such a quick response and your info re perfomance and Air Filters etc.
I will have to give both a go with the air filter first methinks.
With Very Kind Regards
Vladek
Have a look at the air box mod that I made to my car and fitted a K&N filter and appears to work very well with the 4/2/1 manifold and sport CAT and not expensive
Le Mans62 Website - Tips (Air Filter Modification)