Why is a supercharged vehicle's power curve linear?

[XXpl0Sive]

Please explain why.

[poid]

simply the boost pressure rises linearly (more or less) with rpm and hence speed, since the charger is run off the crank

[vti-2]

Ben, shouldn't this be in FI?

[XXpl0Sive]

Oh yes, sorry moved :)

[Slugoid]

What poid said, charger is running off the crank. Unlike turbo's, it has to spool up to a particlar rev range for it to actually produces boost.

[fozee]

As the guys have said will provide boost constantly/linear to rpm as it is driven by the engine.

The Centrifugal type is similar to the turbo as it develops boost when a certain rpm is reached.

I believe the Roots (aka Blower) style s/c delivers boost from idle right through to redline and beyond



Technically, a turbocharger IS a type of supercharger

[soloisbetter]

well all that can said is that The Turbo's will run off the Exhaust/air.. where as the supercharger will run from the engine and will respond instantly to throttle.. where a s a turbo needs certain rpm's and air to actually perform

[kiddoDC2]

does this mean that the supercharged one would hardly experience lag and would be nimble enough to take fast?

[poid]

yeh, a roots type supercharger will have virtually instant response and can make decent enough power, so isnt a bad choice for a low-boost street car.

The only issue is that if you want to go further than a low-boost street car, and look for a larger power increase, the supercharger is less efficient than a turbo and simply doesnt work well at higher boost levels.

A centrifugal type supercharger has lag just like a turbo, as it also needs to get to a certain speed to start compressing the air