[Neil]

Many owners are using a slightly smaller pulley on the supercharger which is increasing the power. Interestingly although Ford quote 550bhp for the GT, many in the UK have been dyno'd at over 590 in stock form.

I hear that the smaller pulley is causing some problems with the inlet tube collapsing (with the additional draw) along with some seals being stressed.

There's a guy in the US who has put twin turbos on his GT and has achieved over 1,000bhp!

Personally, 550+ is more than enough for me tootling around Surrey!