Is a Ford Mustang faster then dodge viper?

It depends on the specific year and model of both the Mustang and the Viper. Generally speaking, the Dodge Viper, especially the higher-performance versions, was historically faster than most Mustang models. However, some higher-performance Mustangs (like the Shelby GT500) could potentially compete with or even surpass some Viper models, depending on the specific track and conditions. There's no single definitive answer.