wastegate hoses--type 44

[Nate Stuart]

The upper, smaller dia. hose, is used to apply pressure to the upper chamber
of the wastegate via the wastegate frequency valve. This is to allow the
computer to increase, and control, the boost. Last weekend when Mark Allen
and I replaced the WG on his 5ktq we ran it with both the upper hose on, and
off. 1.2bar with the hose off, 1.4bar with the hose on.

The lower, larger dia., hose is _much_ more important. It provides manifold
pressure to the bottom of the wastegate to open the WG and allow the excess
exhaust gasses to bypass the turbo, limiting boost. If this hose is cracked,
or the WG diaphram is torn, then the bosst will climb until the computer
(hopefully) cuts the fuel pump out and kills the engine rather violently.

For more images and descriptions check out SJM's page:
http://www.sjmautotechnik.com

Hope this helps!
-Nate

> There are 2 hose connections on the wastegate. What happens if either one
> is disconnected? I think there is one used a vac. port and the other is a
> pressure port where boost pressure is used. Is any of this true? No one
has
> been able to discuss the wastegate on the list, so please let me know if
> you have any info. Thanks.
>
> -ameer