controlling air suspension speed??

how can this be made possible: fast up / slow down. 

a friend of mine told me i could use a throttle valve and put it on the exhaust side. is this the only way? 
what other parts would i need? ex. other fittings etc.
o yea.... i have 1/2" lines.

smaller lines..1/4inch and put the throtle vavles on the outlet side that goes to the bags.. it will control how fast it goes to your bags and how fast it come back out.. 
 
Puttingit on the EX side will work on the down motion than youll still have to add one on the Up side to control the up speed. 
 
So you might as well just use on for front and one for back.. 
 
those 1/2 hoses are way to big for a scion.. even 3/8 it still lifts fast..

yep, that's the easiest way if your system is all together all ready.

its gonna be PITA to run 1/2" in the scion, i'd say spend the extra hundred or so for 3/8" fittings and line.  save you the pains of running 1/2" in the tiny scion

if you need something to slow down your air up then get this.

[url]http://www.suicidedoors.com/12PTCValveFillControls.php[/url]

This goes into the line before the valve for the front and the back.

If you need something for your slow down then get this.

[url]http://www.suicidedoors.com/12NPTValveFlowControl.php[/url]

This goes on the end of your dumb valve.