How much horsepower will a turbo add to Pontiac GTO?

The amount of horsepower that a turbo will add to a Pontiac GTO depends on the specific turbocharger, engine modifications, and tune combination used. Generally speaking, a turbocharged Pontiac GTO can see an increase of anywhere from 50 to 200+ horsepower over the stock engine. More aggressive setups aimed at racing can see gains exceeding 1000 horsepower, but these builds require extensive modifications. These figures can vary based on a variety of factors such as the turbocharger size, boost levels, and other supporting modifications.