Particle System - speed up/slow down release of particles

How?  I'm trying to use a particle system for a vehicle exhaust.  If the vehicle is idling, i want plumes of smoke to release very slowly.  If its accelerating, i want to release more.  I tried using the 'getParticleController().setSpeed()' to adjust the speed…it speeds up and slows down the entire particle system.

The setReleaseRate() member variable seems like the ticket, however it has no effect.  Perhaps i'm using it incorrectly? 

So to ask my question succinctly:

*) How does one control and alter the release rate of the particles in a particle system, without changing the actual speed of rendering/processing of the already released particles?


I think for setReleaseRate() to have any effect you must enable setControlFlow().

Don't quote me on that just in case.

You're right… I gave up originally on flow control as it's speed control affected the whole systems speed.  I wonder if the setReleaseRate method might be better suited as a member of the particle controller (where you turn flow control on/off) rather than as a member of the actual mesh, considering flow control needs to be on for it to have an effect?