Four-inch dust extractor to two-inch cyclone

Gday all. I have a 4-inch dust extractor and 4-inch PVC pipe running in my garage. I’ve recently purchased a cyclone dust collector to mount on a bucket but I wasn’t aware it was 2-inch inlet/outlet. What I’m wanting to know is if I hook my 4-inch dust extractor up to the 2-inch inlet and the outlet am I going to get roughly the same suction power/CFM or will it be restricted by the 2-inch cyclone. Cheers, Zac