CAF and standard 182 airbox - what diameter?

[brucey_182]

I looking to put a cold air feed on my 182 standard airbox to the lower grill. Anyone know what diameter pipe is needed for standard air box?, any recommendations on where to get the pipe and trumpet from?

Going to change the filter for a K-tec or itg also, what best to do with the acoustic valve on the 182 box?

All ideas/pics welcome.

Cheers