I'd personally shift that on and get something better. The internal diameter of the uppipe (turbo side) will be much less than 2.5" (that's the standard exhaust size, post-downpipe). I'm not 100% sure but i think the internal diameter of the standard uppipe is around 1.7" ?
Alyn should be able to tell us what size the ID is on the harvey uppipes, you won't go wrong with one of those.