The biggest frustration with all the power you have in something like a Viper is staying off it! That's really the key to controlling it rather than spending hours trying to find a perfect setup that's fast with no oversteer or wheelspin. Brake well in advance of corners, choose your line and feather the throttle (or lay off it altogether) until your exit point becomes clear then gently feed the power back on until you're straight enough to floor it again.
I actually like the way the Viper handles pretty much as it comes out of the box but then I like oversteering cars (much better than understeer any day of the week!). Strangely enough tho', one of the best ways to improve its handling is to turn the ASM off (all it does is turn predictable oversteer into unpredictable sideways slide). If analogue throttle isn't in your style then turn the TCS up and that'll help keep the backend in line under acceleration (as will a high LSD A setting).