When good turbos go bad...

[scirocco at vintagewatercooleds.com (Eric S)]

Very interesting Drew...many people shy away from the VNTs on mechanical
diesels because of the lack of computer control and their inability to
figure out a way to reliably control the VNT in a mechanical way.  Quite a
few people would be interested in your method if you could do a write up
with some pics, I'd be glad to pass it around (m-TDI is becoming quite
popular lately).

-- 
Eric
www.vintagewatercooleds.com

1981 Scirocco S (m-TDI swap project)
1990 Fox Wagon 1.6 Heron Head 8v
1991 Cabriolet (2.0 crossflow 8v project)


C Boyko said:
> But all in all, the fact that you "enjoyed" it as much as you did proves
> that the concept worked pretty well. Maybe this is just Carrot's way of
> keeping you from that little 77 blondie a bit longer...
> Cathy
>
> On 10:12 am 07/15/07 "Drew Mac" <type53@xxxxxxxxx> wrote:
>> On 7/15/07, Eric S <scirocco@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> >  How where you controlling the nozzles?
>>
>> A dual-diaphragm can - vacuum moved the nozzles to no-boost for idle,
>> and a throttle switch shut the vacuum source down.  This allowed for
>> no boost at idle/low boost cruising.  The (approximately) 11 psi
>> spring in the can controlled the boost pretty well, no spikes.
>> Transition of the nozzles was controlled by the force of the
>> diaphragm, which was smaller than the stock TDI cannister.
>>
>> It worked pretty well all told, from the time I settled on that method
>> (the day before driving to Cincy) to the time the impeller shaft
>> parted.
>>
>> I had just completed a long hard pull in 5th from about 1700rpm (a
>> MAJOR no-no) which put the compressor pretty much smack in the surge
>> zone, and presumably weakened the shaft  I then immediately followed
>> that up with a hard launch from a stop sign which resulted in the
>> catastrophic failure.  Very embarrassing when the cars you just passed
>> drive by you as you're smoking on the shoulder... And I mean
>> SMOKING... ;)
>>
>> Drew
>>
>> --
>> 84 Wolfsburg Ed. Scirocco GTD mit ??berVerteilerpumpe
>> http://scirocco.cs.uoguelph.ca/gtd
>> 77 Scirocco project - Boom Boom Boom...
>> 99 A3 Jetta GL TDI (hers) 02 Jetta GLS TDI (Bloatware)
>> ======================================================================
>> ===
>>
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>
>