The AAZ is a simple waste gate control - a simple spring that opens at X
pressure.  In effect it should behave the same way as the computer
controlled one does as it doesn't compare the ambient pressure with the
manifold pressure.

David Marshall

http://www.hasenwerk.ca
Box 4153, Quesnel BC, Canada V2J 3J2

Engine Conversion FAQ - http://www.hasenwerk.ca/faq

On
Tue, July 1, 2008 22:16, Mike Miller wrote:
>
> Thanks
for the technical part of how it does what it does.
>
> I
realized what it did in effect but what I asked was does the AAZ turbo
> work this way and if it does to what altitude can it feed the
engine the
> full boost the engine expects?
>
>
Mike
>
> On 7/1/08 7:10 PM, "David Marshall"
<mailinglist@FASTFORWARD.CA> wrote:
>
>> It's
all relative...
>>
>> The TDI and most other modern
turbo
>> engines uses a MAP or Manifold Absolute Pressure
sensor.  So, in an
>> absolute vacuum the ECU will see 0 mbar -
at sea level on an average day
>> you will see 1000mbar and at
the top of a mountain it will be say
>> 900mbar
>> -
these values are all with the engine off.  So the ECU controls
>> boost using this MAP sensor - for a stock ALH TDI this is
1950mbar for
>> maximum boost, which if you compare it to the
outside air pressure, it
>> will be higher in a mountain than
at sea level, but in effect, it is the
>> same amount of
pressure on the inside of the manifold.
>>
>>
David
>> Marshall
>>
>>
http://www.hasenwerk.ca
>> Box 4153, Quesnel BC,
>>
Canada V2J 3J2
>>
>> Engine Conversion FAQ -
>> http://www.hasenwerk.ca/faq
>>
>> On Tue,
July 1, 2008 16:04, Mike
>> Miller wrote:
>>>
>>> All,
>>>
>>> When I had an
>> 02 TDI I was told the turbo produced more boost than the
>>> engine
>> was set up for at sea level. This
allowed full power to 5000 feet
>>> where the boost no
longer had to bled off.
>>>
>>>
>>
Also told the 944 turbo Porsche was set up the same way.
>>>
>>> Anyone know is this is true and if it's
true for the TD engines?
>>>
>>> Mike
>>>
>