I think there's alot of b****cks talked about when it comes to cold air feeds . Imo the cold air feeds on the standard airbox are good enough . The engine sucks air in , its not forced in so if you go for an aftermarket filter , running it down where the original air feed comes from or using the original air feeds is good enough .
Without having used a viper , just looking at the size of it i would say that it would restrict the airflow . I had a k+n apollo and the surface area of the apollo was much smaller than that of the standard filter , similar in size to the viper . It definitely lost power and the 5k kick was nowhere near as predominant as it is now , in fact it was almost gone .
I now have a k+n induction filter in an enclosed aluminium tube that has a larger surface area than the original airfilter and it is a definite improvement over the standard air filter . It pulls really hard with no loss of power throughout the rev range and doesn't suffer from any kind of heat soak from the engine bay .