OK, I purchased the Panoz Esperante GTR-1, and was immediately taken aback with its 779hp after an oil change (824hp with Stage-3 turbo). I expected the stock numbers to be a bit higher, so there was some disappointment.
Without spending too much time fiddling about with fine-tuning, I took it out at Indy with the turbo installed, along with Race-Soft tires. While it doesn't handle as poorly as it has in past games, it's still a bit of a pig, as none of the corners can be taken flat-out in 6th gear.
A tap on the brake was needed to settle the nose in on turns 1 and 3, with partial throttle used on turns 2 and 4 to carry as much speed as possible on the front and back straights. I could only manage a low 45.XXX. With some work, it could do a low 44.XXX (or 43.XXX in the hands of a better driver / tuner), but any of the Ford GT race cars can post those times -- and better -- with much less power, and considerably less effort.
I can't say that it was the best 2.5 million cr. I've ever spent.