Down pipes aren't expensive... sport/racing cats are though.
If you buy the above you will essentially have a pre-cat delete and main cat de-cat and also increased the first section from the turbo to 3 inches from the 2.5 inch OEM.
You'd probably lose a little low down torque, but free up that brick wall of a pre-cat and bring down the EGT's and increase horsepower (with the right map of course).
That said, it seems a bit silly to buy this to mate it up to a 800 cell OEM cat though... I doubt there would be much in the way of gains from doing that and just doing a pre-cat delete and using the standard system...
Poll