I haven't spent much time in a stock viper, but I will tell you that my 1000bhp ACR is a menace. On fresh tires, it's wonderful to drive, and I can handle it fairly well. But once those tires begin to wear out, it's over. They disappear so fast, it doesn't matter if you have 100hp on the competition and absolutely smoke them in a straight line, because you'll be in the pits (or sliding into a wall) before you know it. I have to admit, it's very fun though! I did a 20-lap race around Monza with some buddies and we all had max-tuned ACRs, we all had to pit 3 times.