To give an accurate reading of what the car is doing on a dyno you need to generate a large airflow to replicate as near as possible the conditions on the open road. To this end, we have installed the highest airflow dyno cell in the UK. Four one metre radial fans generate a combined airflow of over 120,000cfm (cubic feet per minute).
Two fans are situated behind the vehicle to suck out the hot air generated by the vehicle engine and exhaust and two further fans blow air over the vehicle. With all four fans in operation we exchange the entire air contents of the cell every five seconds. Basically, it’s a wind tunnel with a dyno in it.
i don't believe their figures. i think that they have just bought 4 fans of 30,000 cfm each and multiplied it up, even though only 2 are blowing and 2 are sucking.
even if they have 120,000 cfm, so what? what are is that over? if that's the whole dyno cell area, that isn't necessarily much. if you say that it's over an area of a typical car of about 5 feet high by 6 feet wide, that's only a wind speed of about 45mph. hardly a 'wind tunnel' is it?