Cheers for the advice chaps, it's much appreciated.

Going by flow rates, what would you say a stock (say ford focus minus air con) cooling fan shift in m3/hour... I mean is 2250 m3/hour a decent flow rate? Is it worth running the fan that shifts 2600 m3/hour (bearing in mind thats over £200!)

The cooling fan is for a mk1 Clio Williams by the way and this after market pish fan im running now doesnt shift anyway near as much air as the stock fan or sound like its rotating at even close to the same rate as the stock fan did (current fan is a suction fan)

Just found a conversion chart, minute 1 CFM = 1.7 m3/hour. So thats approx 4500CFM on the £200 cooling fan

It sucks really as I'm not able to run a larger radiator to enable fitment of a larger fan. I had to downsize from the last alloy rad as it fouled the back plate for the air filter (as im running iTB's). It had a thicker core also, so this cooling fan just abit cut it at the time