magnex is a twin pipe system (2" IIRC) so thats 4" flow.

the mongoose is a 3" single pipe system

I wouldnt think either restrict up to say 400 brake.

The magnex is quiet though (makes a bit of noise on boost)

I had a maxnex and swaped it for the goose.

Not too sure on the diameter of the scorpion but 2.75" seems to ring a bell?