Slide Throttles

[Todd Knighton]

Paul,
	Another disadvantage to slides is on turbo motors.  One surge, or when
you slam the throttle closed, they tend to stick closed because of the
massive pressure placed on top of them.  Whereas the butterflies offset
the pressure equally on both sides of the shaft.
	Barrel throttles give very strange low flow characteristics, but do
have very nice flow at wide open.  They are hard to seal as well.  The
Oldsmobile Aerotech that set all the land speed records used it.  But
they said for emmisssions stuff it wouldn't work because of the leakage.

Todd Knighton
Protomotive Engineering


Edward C. Hernandez wrote:
> 
> Paul Shackleton wrote:
> 
> >slide throttles... pros & cons compared with butterfly throttles?
> 
> One advantage is zero flow loss when a slide throttle is wide open:
> there is nothing left in the flow path. A con would be constructing one
> that doesn't leak with the room available in the engine bay; it has to
> slide SOMEWHERE. I have seen barrel throttles, which is basically 100%
> shaft with a hole the size of the bore, sort of like certain kinds of
> hydraulic/pneumatic valves. They don't need that much room and also
> provide zero flow loss at WOT. You can DIY anything given enough
> patience, time, money...
> 
> --
> Ed Hernandez
> Ford Motor Company
> ehernan3 at ed8719.pto.ford.com