Those numbers are of course with a protune.[/b]
With a Protune, I agree, sounds about right... but, with an OTS "flash" I would highly doubt it, and by "stage 2", Cobb generally does their Stage 2 maps with a full turboback exhaust + reflash... although it's a pretty well known fact in the Subaru world you can get away with running their Stage 2 map with just a full length downpipe.
I don't see the cat-back on the Speed3 as being a big limiting factor, at least not on the stock K04 turbo, but running a full 3" turboback would surely help your EGT's, which isn't a bad thing.
