Wastegate Workings

[Robert Deis]

On Wed, 6 Dec 2000, JOHN URIBE wrote:
>
> Can anyone shed some light on how the wastegate is controlled?
> 

Let's see if I learned this right:

The wastegate is held closed by a spring that opposes the pressure in the
turbine that's trying to open it.  When the pressure in the turbine
exceeds the spring force, wastegate opens and you boost levels off.

The vacuum line you found comes from a boost source (intake
manifold?) through the solenoid valve.

When the ECU opens this solenoid valve, the boost pressure assists the
spring and holds the wastegate closed.  When the ECU opens the valve,
there is no assist to the wastegate spring, so it opens as above.

The ECU typicly modulates this valve it order to maintain the desired
max boost pressure.

Did I get it right?

-- 
------------------------------------------------------------------------------
  Rob Deis                  "Let the people know beforehand what the law
  MiB3347                      is and what they are to expect." 
  rdeis at io.com                              -- 18th Congress, Rec. 75