Which Intake

[AL8001 at aol.com]

In a message dated 99-03-07 12:59:45 EST,
frederic.breitwieser at xephic.dynip.com writes:

>
>But, if you place the throttle blades BEFORE the fresh air
>side of the turbos, for a few seconds anyway, the turbo will
>keep pressurizing the plenum while creating a vaccum on the
>pre-turbo side... thus giving you less throttle reponse when
>you let up on the gas pedal.  Most OEMs, as far as I can
>tell, place the throttle plates after the turbo, and I
>copied this on my twin-turbo setup, with two throttle
>assemblies.
>
>
>-- 
>Frederic Breitwieser


Early Chrysler 2.2 turbo cars had the throttle body on the inlet side of the
turbo.  Later cars had the throttle body on the outlet side.  Anyone have or
has driven both? 

A tbody on the inlet side would produce a vaccume during light throttle
openings.  This would tend to draw oil past the turbo seal.  If the tbody is
after the turbo, the compressor seal would only see boost or atmospheric
pressure.

I agree with FB's above reply.  Though a after turbo tbody system should have
a blowoff valve between the turbo and the tbody.  This relieves pressure when
the throttle is snaped shut, reducing stress in the turbo and allowing the
compressor stay at speed.  SAAB/ Mitsubishi and others use this valve.

 
Harold