standard cars or hybrids?
The RZ supra can Muster over 1000 Hp as can the R34 GTR Skyline there a few more (non race cars) that can put this sort of power as well but dont have them at hand ATM
you can break 1000hp with the Zonda C12S (I havent tried the non S) but I dont like the way it handles. I think you can get it to 1081 - around supra range.
the non racing viper can hit like 10XX umm lets see the mil dollar vette and viper hit bout 980 umm thats bout all i tuned oh ya the 787b hit like 985ish
I think the Jaguar XJ220 hits high 900's, but I can't remember, I haven't driven it since I got it.
But, that also could be the R390 road car, or something of that nature.
IMO horsepower should be used if and only if you need it thats why I mostly drive with cars under 500 hp. but most of the time its under 400hp....sometimes it is fun to get in a car with a lot of hp and just go as fast as you can but you cant control your car as well.
Almost any race car is capable of over 1000hp and most sports cars (i.e. Skyline, rx-7, supra, vette, viper, etc.) are capable of around 800hp-+1000hp.