VRS Northampton did some testing with stock inbox and bigger intake pipe and it worked well. Even with OEM paper filter.

I have found in past when testing paper Vs panel that paper flowed better and actually let's through less stuff.
 
How do you rate the ramair kit? how much did you pay?



Haven't fitted it yet but had one on my edition 30 previously and it seemed to work well. No dyno to prove any before and after changes but the car seemed to feel more responsive and the noise was good.