The straght on the track doubles as a drag strip at Spokane Raceway....1/4 mile wind up and about that much distance to slow down. I don't remember the exact length. I've spent two days on the track with my '85S 928. When I was still learning the track and my car, I (ignorantly) once went into turn 1 after the long straight at about 120mph and went into a 4 wheel drift from which I barely slowed down and cleared the corner otherwise I'd have hit some small trees (or worse). Not being an experienced driver, I take that curve now pretty easily at about 98mph or therebouts, although people who know what they are doing and have their cars set up well can do wonders on that track. I could get 147mph in 4th gear in the 928 on the straight..but as soon as I shifted into 5th. it was like I hit a wall. The 928 just settled into Grand Tour mode and started crawling. I guess it would take a really long Nevada straight to top out 5th. It's a great track...run counter-clockwise with lots of variation. 2-3 years ago a 928er rolled his nice Guards Red GTS. We've had a few cars run off the track but no injuries that I know of.
On the straight, I've witnessed a twin screw supercharged '86.5 and a Ford Shelby Cobra turn almost 170mph on the straight (at least I was told that). I just know I was going really fast and they went around me like I was barely toodling along. This Sat. an Aston Marton is supposed to show (928 owner).
I'm not sure what the 968 would do on the track but there was a 951 the last couple of years which was really doing great in the curves (very, very nimble) but the 928s were passing him on the straights. The 951 did very well. I suspect the 968 would do well too.
Coincidently, there's a "track attack" by 928s (mostly) this coming Saturday. $200. At this late date it would still be possible to attend if you can prove track experience before. The deadline is past for those who would require a trainer. The trainer rides with you, shows you the apexes, where to break, etc. etc. Well worth the money. You clean out your cars, wear helmets, etc.
There's nothing like a good track to see what your car is capable of.
Harvey