How much horse power does a turbo add?

Answer 1

A correctly set up turbo typically can add as much as 50% more power to an engine. With that said, the power a turbo adds is very dependent upon the wastegate, and fuel curve set. Turbo's are notorious for being very sensitive to the fuel/air ratio. You almost need a computer controlled fuel delivery system and ignition control system to get the most from a turbo. As the boost pressure rises, the timing should automatically retard. Conversely, the fuel delivery must increase as the boost rises and engine speed increases. I only mention these because a turbo is much more sensitive than a traditional belt or gear driven supercharger to these variables. Also, one item to keep in mind is the engine. If it was a standard engine you are adding a turbo charger to, the compression ratios will be too high for a turbo to properly fill the cylinders, limiting the amount of boost you can use or develop due to pre-detonation of the fuel. The pistons (and entire reciprocating assembly also) will undergo a good deal more stress and forged pistons with a compression ratio of around 7:1 are recommended. You should go to 1 heat range cooler with the spark plugs to start and make sure the entire ignition system is in good shape. Ignition amplifiers are recommended for use with Super or Turbo charging. There are several variables too numerous to list here that can also alter the performance of a turbo-charged engine. The size of the turbo will affect the turbo-lag which is the hesitation you feel when you stomp the accelerator and the turbo takes time to spool up. If you are going to go to the trouble of installing a Turbo, look into intercoolers to keep the incoming air cooler, make sure the induction filters and system are high performance, free flowing and that the exhaust system is sized to handle the additional output as well. If they are not, you are wasting a portion of the extra power the turbo can provide. A fuel injected vehicle will need larger injectors. Running the Turbo while failing to provide adequate fuel will result in a lean condition, engine damage and eventual failure.