I recently fitted one of Hardhitters de-cat pipes, and its made a lot of difference at top end. I've got a GPS speedo device, and before fitting the pipe 104mph seemed to be about the limit of the car, and it took a while to get there.
Tonight (given that weather conditions are good, no wind), I got 111mph twice (and i'd say there was probably another couple of mph had I not run out of road), and it breached the 100mph barrier much faster than it has ever done before. I don't normally drive my car like this, but it was running well so thought I'd try it once - then had to try again to make sure
Anyway, 111mph in a GT is a shade under 6250rpm, which is about the highest I've ever taken the engine, I don't know where the limiter is set at, but the book quotes max power at 5900rpm, so I don't usually see the point in going above that. In fact if I'm giving it some I usually change a bit earlier to keep within the torque band which seems to be highest between about 2800-4500 rpm. Another thing is that the GT's speedo over-reads considerably - at 111mph GPS confirmed it was showing 119mph on the clock - so don't take your speedo's as gospel folks, they will pretty much all over-read by some amount (its also a built in safety 'feature' I believe, to stop you exceeding speed limits too easily).
So yeah, basically this is to say that the GT has again surprised me tonight, its a great little car, almost standard (just the Hardhitter chip and de-cat pipe), running on Optimax its really doing well - so glad I kept it now!
