at the end of the day its probably not going to be that, but i would put it back on, the heat shields were put in place for a reason, im a firm believer in heat soak and the ways it disrupts performance, i've vhanged to a hi mount gt35r setup but my ive heat wrapped my whole exhaust manifold, dump pipe, intake pipe that goes over engine and intake pipe off turbo, and got a turbo bag for the ex housing on turbo, minimising heat can have good effects on the cars performance... my 2 cents anyway