[s-cars] Bypass Valves and Pressure Losses (Uh, Pizzo??)

Lewis, Gary M gary.m.lewis2 at boeing.com
Mon Dec 22 17:51:38 EST 2003 

Ok, no caffeine at lunch, ready to reply...

I put the thing in the way the instructions said, and I wrote it correctly, so we move on to plan c...

Seriously, if I take Hap's comments about re-orienting the BPV in the other direction, I would need little spring as the valve bottom is either in vaccuum (more or less), or at sea-level (14.7 psi), and the top is either under boost (up to 26 psi), or vaccuum.  If I have it the way it is now, in accordance with instructions, the valve bottom is at various states between vaccumm and 26 psi boost, and the top is the same.

What does that mean to me?  That the way I have it, under boost, top and bottom of valve see more or less the same pressure, and the spring keeps the valve from opening.  Off throttle, bottom sees boost, top sees vacuum, and the pressure differerntial is great enough to push open spring, and whoosh, air is bypassed.

If I move it around the other way, under boost, valve is kept closed by pressure from the top (manifold pressure), as the bottom is 14.7 or less.  Off throttle, bottom is at 14.7, top is under vaccuum, 14.7 psi pushes valve open, high pressure rushes in from the side of the valve into bottom of valve.  No mondo spring necessary.

Do I have "Headupbutt Syndrome"??  Or have I got it right?

And thanks for all the patience...

Gary Lewis

1995.5 S6 Avant, Green/Ecru, RS2 MAF, RS2 Exhaust Manifold, RS2 Injectors, Custom Turbo (K26 Turbine, Factory K26 Cold side (Audi Works '999' P/N) with 50mm intake and custom Innovative Turbo compressor wheel), TurboXS Type 25 Bypass Valve, Bilsteins, Eibachs, Big Reds, Spec II Clutch.



> -----Original Message-----
> From: Joseph Pizzimenti [mailto:pizzoman at yahoo.com] 
> Sent: Monday, December 22, 2003 12:09 PM
> To: Lewis, Gary M; CaptMagu at aol.com; s-car-list at audifans.com
> Subject: RE: [s-cars] Bypass Valves and Pressure Losses (Uh, Pizzo??)
> 
> 
> http://www.decaf.com/switch/
> 
> 
> 
> --- "Lewis, Gary M" <gary.m.lewis2 at boeing.com> wrote:
> > I'm having a F'n morning...
> > 
> > Godda#it, now I gotta go home at lunch, look at the
> > F'n directions, look at the F'n valve, and write
> > another F'n email.
> > 
> > I'll report back with either a) stupidity (I wrote
> > the wrong thing) or b) stupidity (I installed the
> > damn thing incorrectly), or c) I put a hit out on
> > you for making me drive all the way home.
> > 
> > Off topic, I was gonna drive home anyway, as I
> > forgot the F'n caliper brackets in the F'n garage
> > this morning, and I have some lift time scheduled.
> > I also have some nice Primitivo (Eyetalian
> > Zinfandel, a close cousin) grapes fermenting that
> > should have tha cap punched down.  Nice, 28 brix,
> > perfect p.H., a Tuscan wet dream.  Delish.  And the
> > wagon can hold ~500lbs of grapes easy.  Fastest
> > agricultural vehicle in the world...
> > 
> > Bitc# bitc# bitc#...
> > 
> > Thanks Joe,
> > 
> > Gary Lewis
> > 
> > 1995.5 S6 Avant, Green/Ecru, RS2 MAF, RS2 Exhaust
> > Manifold, RS2 Injectors, Custom Turbo (K26 Turbine,
> > Factory K26 Cold side (Audi Works '999' P/N) with
> > 50mm intake and custom Innovative Turbo compressor
> > wheel), TurboXS Type 25 Bypass Valve, Bilsteins,
> > Eibachs, Big Reds, Spec II Clutch.
> > 
> > > -----Original Message-----
> > > From: Joseph Pizzimenti
> > [mailto:pizzoman at yahoo.com]
> > > Sent: Monday, December 22, 2003 11:50 AM
> > > To: Lewis, Gary M; CaptMagu at aol.com;
> > s-car-list at audifans.com
> > > Subject: RE: [s-cars] Bypass Valves and Pressure
> > Losses (Uh, Pizzo??)
> > > 
> > > 
> > > Gary,
> > > The pressure side should be feeding into the side
> > of
> > > the piston, not the bottom.  No wonder you breezed
> > > through the install.  :-)
> > > 
> > > It's a bit at h doing it the right way, but isn't it
> > > always?
> > > 
> > > Pizzo
> > > 
> > > --- "Lewis, Gary M" <gary.m.lewis2 at boeing.com>
> > wrote:
> > > > Hi Hap,
> > > >  
> > > > I oriented it from the bottom (pressure side),
> > as
> > > > the instructions indicated, with 6 shims, as
> > Pizzo
> > > > indicated.  It works far better than the old
> > 710N
> > > > unit from a pressure loss standpoint (I gained
> > 200
> > > > rpm in 4th gear).  My current automotive goal in
> > > > life is to reduce pressure losses in hope of
> > getting
> > > > 26 psi at 3,000 rpm.  I'm making progress.
> > > >  
> > > > I think the idea you postulate is really a neat
> > one.
> > > >  It should provide far better response than a
> > > shimmed-to-the-max BPV.
> > > > Uses vaccuum primarily, not pressure and vaccum
> > to open the
> > > valve.  I
> > > > will try it.
> > > >  
> > > > Sorry I took so long to answer, but I needed to
> > > > think about this for a few days.
> > > >  
> > > > That Trevor is something else, ain't he?  The
> > more I
> > > > talk to him (virtually of course), the more I
> > want
> > > > to drive his car.  No to mention your of
> > course...
> > > >  
> > > > Thanks Again,
> > > > Gary Lewis
> > > > 
> > > > 1995.5 S6 Avant, Green/Ecru, RS2 MAF, RS2
> > Exhaust
> > > > Manifold, RS2 Injectors, Custom Turbo (K26
> > Turbine,
> > > > Factory K26 Cold side (Audi Works '999' P/N)
> > with
> > > > 50mm intake and custom Innovative Turbo
> > compressor
> > > > wheel), TurboXS Type 25 Bypass Valve, Bilsteins,
> > > > Eibachs, Big Reds, Spec II Clutch.
> > > > 
> > > > 	-----Original Message-----
> > > > 	From: CaptMagu at aol.com
> > [mailto:CaptMagu at aol.com]
> > > > 	Sent: Thursday, December 18, 2003 1:23 PM
> > > > 	To: Lewis, Gary M; s-car-list at audifans.com
> > > > 	Subject: Re: [s-cars] Bypass Valves and
> > Pressure
> > > > Losses (Uh, Pizzo??)
> > > > 	
> > > > 	
> > > > 	Gary
> > > > 	
> > > > 	I have the H34 TurboXS right now. Do you have
> > it
> > > > plumbed from the side? In other words is the
> > > > pressure feed from the turbo plumbed into the
> > side
> > > > of the piston. If not you'll want to reorient it
> > > > this way and then you won't need any washers. In
> > > > fact I went to a softer/shorter spring. I had
> > > > shimmed my old H34 like crazy, well beyond the
> > > > provided washers and was still having a problem
> > > > getting it to hold boost. I talked directly to
> > the
> > > > TurboXS folks a while back when there was a
> > thread
> > > > running on mounting BPVs backwards. They
> > admitted
> > > > that for high hp applications that this was the
> > way
> > > > to go and sent me a brand new H34 configured for
> > a
> > > > hard mount at the side. Tha's what I have now
> > but
> > > > even with the softer/shorter spring I'm still
> > > > getting that boost surge at throttle lift from
> > > > boosted runs. It was Trevor Frank's idea to try
> > a
> > > > softer spring and it has greatly improved the
> > > > problem but has not totally fixed it. My next
> > try is
> > > > a beefier diaphram unit. The stock Mitsu EVO BPV
> > > > couldn't hold my turbo's force.
> > > > 	
> > > > 	Hap, boostin and surgin in Everboost, Maguire
> > > > 
> > > > _______________________________________________
> > > > S-CAR-List mailing list
> > > > S-CAR-List at audifans.com
> > > >
> > http://www.audifans.com/mailman/listinfo/s-car-list
> > > 
> > > 
> > > =====
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> > > The following statement is false.
> > > The preceding statement is true.
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> > > 
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> 
> =====
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