Turbobike Web Site www.Turborick.com

Re: [turbobike] Carb Question

Christer Johansson (christer.johansson@mbox383.swipnet.se)
Mon, 22 Nov 1999 22:38:19 +0100

Yes it is insignificant, just have a look at the draw through kits ,like
Mr turbo, almost no plenum and no pipes ,intercooler.
But in normally aspirated mode , this is a restriction, hence the
priority breather valve. B.t.w Im working on My own version
of the priority valve , Im using a 2 stroke reed valve, has anybody
tried this before?

Christer

shammar@nsk-corp.com skrev:

> Don't worry: we like counter-discussion.  That's the point of this forum.  I do
> think that Abraham is onto something.  I believe that the amount of time it will
> take to fill the plenum will be insignificant.
>
> Bryan <bgoodwin@iquest.net> on 11/22/99 12:26:04 PM
>
> To:   Bob Shammas/EQA/Nsk-Corp@Nsk-Corp
> cc:   FFDennis@aol.com, turbobike@natvideo.com
> Fax to:
> Subject:  Re: [turbobike] Carb Question
>
> Bob, I realilze that boost response and timing is primarily controlled by
> the turbine sizing. However, that assuming all else equal. Given a fixed
> A/R on the turbine, increasing the size of the plenum volume will increase
> the time it takes to fill it. What I'm not sure of is how dramatic an
> effect this will have.
>
> P.S. Not trying to argue, just making friendly counter-discussion. :)
>
> At 07:49 AM 11/22/99 -0500, shammar@nsk-corp.com wrote:
> >
> >Realistically you'll never get too much plenum volume.  The need for plenum
> >volume is all but forgotten on four cylinder engines since the intake
> events of
> >the cylinders provide an almost uninteruppted flow out of the compressor.
> >However, a larger accumulator volume reduces manifold pressure fluctuations
> >between intake events.  On a twin, you'll run into surge much more easily and
> >must have a huge plenum.  Having a large plenum is akin to being able to
> blow up
> >a balloon with full lungs the whole time.  You don't want empty lungs
> before the
> >intake valve event has finished.
> >
> >Turbine response (how fast it makes boost) will be governed by the exhaust
> event
> >and turbocharger matching.
> >
> >That's just my $0.02.  I've built a few bikes but that doesn't mean anything
> >either.
> >
> >Bob
> >
> >
> >
> >
> >
> >
> >Bryan <bgoodwin@iquest.net> on 11/21/99 01:37:26 PM
> >
> >To:   FFDennis@aol.com, turbobike@natvideo.com
> >cc:    (bcc: Bob Shammas/EQA/Nsk-Corp)
> >Fax to:
> >Subject:  Re: [turbobike] Carb Question
> >
> >
> >
> >I think the only problem you would run into there is that the volume of the
> >airbox would be too large. This might cause the turbo to boost later.
> >
> >
> >
> >
> >At 10:38 AM 11/21/99 EST, FFDennis@aol.com wrote:
> >>In a message dated 11/19/1999 23:56:32 Central Standard Time, ABNZX9@aol.com
> >>writes:
> >>
> >><< Now for another question how about intake plenum and attaching it to CV
> >> carbs?  Should I buy a set of velocity stack and machine them in order to
> >>fit
> >> an intake plenum to the carbs that way?   I have a feeling that the intake
> >> plenum I am currently using is robbing me of effieciency.
> >>  >>
> >>
> >>You raise another interesting possibility.....If you can encapsulate the
> >>entire carburetor within a plenum, and then pressurize the entire plenum,
> >you
> >>eliminate the need for separate pressurization lines for bowl vents, CV
> >slide
> >>vents, etc., as you would have equal pressure operating on all sides of the
> >>crab.  The pressure in the venturi would be lower than the other areas,
> >which
> >>is how a carb works.  Your next problem is then to seal the throttle cables
> >>and fuel lines where they pass into the plenum.  I've seen ram air setups
> >>like this.  It seems to me that a turbo plenum could get away with being
> >less
> >>aerodynamic internally due to the mechanical pressurization.
> >>
> >>Just my .02.........lots of book knowledge and reading, I've never built a
> >>turbo bike (but I have a KZ 900 motor in pieces, bead blasted, for a future
> >>project......)
> >>
> >>Dennis
> >>'99 M2 Cyclone
> >>'87 KLR 650 Urban Assault Vehicle
> >>'78 KZ900 bike in boxes
> >>
> >>
> >bgoodwin@iquest.net
> >FZR1000 turbo EFI
> >(aka The Money Pit)
> >
> >
> >
> >
> >
> >
> bgoodwin@iquest.net
> FZR1000 turbo EFI
> (aka The Money Pit)