There is SO much conflicting information going around on here about whether to completely remove the heatshield when fitting a cat-free downpipe, or not. Besides the obvious point of - Subaru would not have put it there if it wasn't neccessary - surely if you wrap the DP up nicely, you shouldn't need it?! Also, more cool air would get to the turbo wouldn't it???

Comments please (because my wrapped ScoobySport DP is getting fitted today, and I don't know whether to cut the heatshield or remove it altogether).

 

The heatshield is mainly there to protect the rest of the engine bay from the vast amounts of heat radiated from the turbo. It also protects the turbo from damage in case any cold liquid is dropped on the turbo when it is hot.
There is another option which you can adopt. You can cut the side skirts of the heatshield and this way you can fit a downpipe and still retain your heatshield. At least you retain the upper part which is the most important.

 

bear in mind that the original d/p tends to hold heat with the Cat, whereas the scoobysport downpipe draws the heat away from the system much more efficiently.

simon