How much more horsepower does a blower give to an engine?

The amount of horsepower a blower adds to an engine depends on several factors, including the type of blower, engine size, and boost level. Generally speaking, a centrifugal supercharger can add anywhere from 50 to 150 horsepower, while a roots-type supercharger can add 100 to 200 horsepower. Twin-screw superchargers are the most efficient and can produce up to 300 horsepower.

Superchargers work by compressing the air that enters the engine, which allows more fuel to be burned and produces more power. The amount of boost a supercharger produces is measured in pounds per square inch (psi). A boost level of 6-8 psi is typically considered safe for most engines, but higher boost levels can be used with forged internals and other modifications.

It is important to note that adding a supercharger to an engine can put additional strain on the drivetrain, so it is important to make sure the transmission, driveshaft, and rear end are up to the task. Additionally, superchargers can cause the engine to run hotter, so it may be necessary to upgrade the cooling system.