Question for you turbo experts

[Todd Phenneger]

Heya,
  Only one point I want to make.  Its not a Blow off
or Pop Off valve.  They vent to atmosphere.  Its a
recirculation or bypass valve.  Or as the TT folks
like to call it a Diverter Valve.  It keeps the air in
the air stream to keep mixture correct and keeps turbo
spinning as well as reducing the effects of pressure
surge or spike.
l8r
  TOdd

--- Jukka Majanen <jiipm at sci.fi> wrote:
> 
> -----Alkuperäinen viesti-----
> Lähettäjä: Jukka Majanen <jiipm at sci.fi>
> Vastaanottaja: Beatty, Robert <BeattyR at ummhc.org>
> Päivä: 22. elokuuta 2000 20:14
> Aihe: Vs: Question for you turbo experts
> 
> 
> Robert Hello!
> 
> I´ve been working and hobbying with turbos since
> `80s,
> but still can`t say I´m an expert, because every
> model 
> or installation is different. ( wanted to say that, 
> `cause 
> You asked for an expert :)
> 
> 1.
> When turbo engine isn`t under the load it works as
> an N/A.
> It can suck small amounts of oil through the metal
> ring sealing
> to the manifold and it goes everywhere. I think
> slight leak isn`t 
> a problem of the turbo, but it can make trouble to
> the diaphgram.
> 
> If You did mean with outer side the ATM-side, it
> means, there is
> some tear in the diaphgram. Then it wouldn`t open
> the WG and
> boost will increase till the shutdown value?
> 
> 2.
> Smaller turbo will decrease the turbo lag, but there
> will be problems
> at maximium load because of the backpressure, if You
> need lots of
> the power. Bigger housing will decrease the
> throttle, but turbine wheel
> may overspeed. Original turbine is just a
> compromise, if there was a
> solution, every engine had a charger.
> 
> 3.
> Exhaust driven centrifugal blower, a turbo, has it`s
> limits You have to
> accept: fast response, great power, or something
> between them.
> 
> Answers You did get:
> From E:
> Higher octane just prevents knocking, nothing to do
> with potential energy,
> if mic hears the knock. it decreases the boost or
> the ignition advance,
> nothing else.
> From J:
> Blow off- or circulation valve ( we call it pop off
> ) is good to prevent Your
> cooler to blow, or older engines not to knock (off).
> But it`s not a way to
> regulate the boost. Every time it opens, charger
> overspeeds and after 
> a certain time Youre out of Your turbo bearings.
> Beautiful blue smoke...
> 
> BTW for R.
> 
> You offered that electrical manual, haven`t heard
> about You. Don`t want to
> sell it anymore?
> 
> Regards
> 
> J.P.M  -91cq
> 
> 
> 
> 
> 
> >Couple of turbo questions for those of you that
> have alot of knowledge about
> >them....
> >
> >I currently own a 87 5k tq with Scott M's eprom mod
> and a 1.8 bar spring.
> >ATP slotted rotors and metallic pads.  Car is
> otherwise bone stock
> >mechanically.
> >
> >I had an R/Z ECU mod previously and while it was in
> at one point just before
> >i took it out, I noticed what seemed to be a power
> drop.  I have run codes
> >and checked various things and since then I have
> also pulled the head to
> >repair the exhaust manifold and engine mount.  The
> car was running at the
> >normal 1.3 bar (US) during the past few weeks while
> waiting to send out my
> >puter to Scott and was running fine.  I have put
> the ECU mod in and while i
> >was replacing the stock spring with the 1.8 bar
> spring, I found a small
> >amount of oil under the waste gate cap on the
> diaphragm.  I also have only
> >seen 1.8 very briefly as well.  I will be
> re-verfying WOT switch as well.
> >
> >questions are....
> >
> >1.  Is a slight amount of oil at the outer side of
> the W/G diaphragm normal
> >or is it a indication of a slight tear in my W/G
> manifold.... would a tear
> >cause a slight power drop or would it be much more
> significant?
> >
> >2.  If i was to consider a turbo upgrade, what
> would I be looking for to
> >decrease turbo lag?  A smaller turbo such as a K24?
> Or a hybrid?  Of which i
> >have no knowledge.  Essentially I am not racing
> this car just driving it on
> >the street, however i would like a bit faster
> acceleration then it currently
> >has.  
> >
> >3.  What specifically makes one turbo different
> from another ie... a smaller
> >turbo reduces lag correct?  what gains does one get
> from a larger turbo?
> >and what is a hybrid specifically?
> >
> >Thanks
> >
> >Rob
> >
> >
> >_______________________________________________
> >Quattro mailing list
> >Quattro at audifans.com
> >http://www.audifans.com/mailman/listinfo/quattro
> 
> 
> 
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=====
Todd Phenneger
    83' ur-q (awaiting a 20vt)
    84' 4ktq  fun but I'm sick of CIS.

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