UnstableAviator
Dual Given.
- Joined
- Mar 12, 2003
- Posts
- 303
Yellow Snow,
You are correct in your description, but you don't seem to understand the relationship between the throttle position, manifold pressure, and RPM. Manifold pressure can be changed by the RPM or the throttle.
In the example you cited, the throttle is opened therefore letting all avaliable outside air pressure to "rush" into the engine. Barring the restrictions present in any induction system, this wide-open throttle MP will be the outside atmospheric pressure. It doesn't matter what your RPM is, since there is no restriction you will always have the full avaliable MP. So basically, anytime you open the throttle (past idle) you'll see an increase in MP. (Provided you aren't at a partial throttle setting at higher altitudes)
Actually, the air is "backing up". If the RPM has not changed, as in a constant speed prop, there is no increase in engine demand for air. You are simply removing the restriction and allowing all avaliable air pressure to better fill the cylinders, making more power. It was demanding the same volume of air at the lower throttle setting, but we weren't allowing it in.
You are correct in your description, but you don't seem to understand the relationship between the throttle position, manifold pressure, and RPM. Manifold pressure can be changed by the RPM or the throttle.
In the example you cited, the throttle is opened therefore letting all avaliable outside air pressure to "rush" into the engine. Barring the restrictions present in any induction system, this wide-open throttle MP will be the outside atmospheric pressure. It doesn't matter what your RPM is, since there is no restriction you will always have the full avaliable MP. So basically, anytime you open the throttle (past idle) you'll see an increase in MP. (Provided you aren't at a partial throttle setting at higher altitudes)
There is no back-up of air, the engine is actually increasing its power output and taking in more air.
Actually, the air is "backing up". If the RPM has not changed, as in a constant speed prop, there is no increase in engine demand for air. You are simply removing the restriction and allowing all avaliable air pressure to better fill the cylinders, making more power. It was demanding the same volume of air at the lower throttle setting, but we weren't allowing it in.