Hi guys I had a noob question but i really need to know this, does boost vary with the amount of throttle you give to the car, lets say your car is suppose to be 30 psi will it reach 30 psi at that specific rpm with Full throttle and if you give less throttle it'll be less boost at the same rpm?

Does it depend on the turbo also?

 

It depends on a few different things. Throttle amount is one of them. Your turbo, exhaust, tune, etc.. all contribute to how much boost you reach at any given time.

 

I think I know what you mean.

For example I can be at 5K RPM with no boost at all.
Or I can be at 3K boost at 25psi.

On my car (stock turbo viii) the boost is really connected to how much throttle I give the car. Its very responsive in the entire RPM range. Even around 2.5K.

But in another larger turbo car I have rode in the turbo is very laggy and you could floor it at 3.5K with almost no boost at all.

Depends on the load, throttle and the turbo size. Like the person said above it really depends on so many variables.

 

you got it!

 

Turbocharger shaft rotation is not directly related to engine RPM's. Turbines are driven by exhaust gas pressure. So, there is no constant, or proportional relationship that exists between boost pressure and engine RPM.

Superchargers as distinguished from turbochargers are mechanically driven off an engine's rotational force via gears, pulleys, belts etc. So, for a supercharger, boost pressure is directly related to engine speed depending of course on drive reduction.