Intake manifold construction, intercoolers

[Huw Scourfield]

Is this the 2V per cylinder PRV or the later 4V one, I have a Volvo version
under the bench in my workshop, know someone who runs one at 30 psi boost,
pretty impressive!
    Huw
----- Original Message -----
From: Rausch, Bernd <br at rnt.de>
To: <diy_efi at diy-efi.org>
Sent: 05 December 2001 14:00
Subject: Intake manifold construction, intercoolers


>
> Vibration is a point I did not think about before.
> Does anyone on the list run an air/liquid intercooler and can confirm
> the sizing information from Spearco ? I thought that an a/l coolder is
> more effective and smaller in size than an air/air cooler.
>
> The engine is a Renault/Peugeot V6 3L 24V, with Garrett GT twin
> ballbearing turbos (GT25 Turbine, T3-60 compressor). max RPM is 7200,
> boost will be about 1.2-1.5bar. The ECU is a Pectel T6M.
>
> Bernd
>
> -----Ursprüngliche Nachricht-----
> Von: Kevin _ [mailto:kiggly at hotmail.com]
> Gesendet: Mittwoch, 5. Dezember 2001 05:52
> An: diy_efi at diy-efi.org
> Betreff: Re: AW: Intake manifold construction, intercoolers
>
>
>
> > > Heck, then make it a 7 butterfly system.  Or even 8.
> >
> >To what end? Idle control? Throttle re-opening response by closing
> >off the plenum as well as the runners?
>
> KART cars last year (and probably this year too) used an extra throttle
> that's on the plenum and electronically controlled to limit boost.  I
> guess
> they found they could react faster there to limit a spike event than
> they
> could with controlling the wastegate.  I'm guessing they also have a
> good
> spike wanting to naturally happen after <100ms shift (I don't know for
> sure
> what their shift times are).
>
> >Opening the throttle to a large plenum will require the turbo to
> >fill that volume as well as that of the runners.
>
> If you do a throttle before all that volume like you were saying, its
> really
> going to have terrible throttle response.
>
> >OTOH, if you instead throttle the runners, the 'plenum' is already
> >filled with high-pressure charge and starts to fill the runners
> >sooner from the reservoir in the 'plenum'. As the throttles close,
> >the reservoir accumulates some pressure and a subsequent re-opening
> >of the throttles can benefit from the store if the over-pressure
> >hasn't bled out through the turbo.
> >
> >Which system will have less lag?
>
> The system with 6 throttle plates will have less lag.  It should also
> have
> much, much better throttle response.  You will have to make a plenum of
> air
> pressure from all 6 runners past the throttles though to get a MAP
> pressure.
>   This can just be 6 lines tee'd together, just keep the lines as short
> as
> possible and use, probably, 1/8" or 3/16" diameter hoses.
>
> >A great number of successful competition vehicles do use separate
> >throttles; typically slide-throttles because they can afford them.
> >In terms of flow at part-throttle, the slide-throttle offers little
> >advantage at much greater risk of sticking (or leaking in typical
> >setups).
>
> You can't use a slide throttle on a street car though.  There is
> terribly
> inconsistent flow through them at part throttle.  I liked the stratus
> touring car that had barrel throttles though, those were cool as hell!
> They
> split at the middle and rolled away (like double-doors opening) to make
> a
> completely smooth runner at WOT.  Slide throttles are your best bet by
> far.
>
> >The shafts will have to be thin to minimise obstruction at WOT.
> >The shaft has to be 'machined' to attach the butterflies.
> >Given the flow rate and engine capacity, each runner would be
> >around 70 mm diameter with a similar size of throttle plate.
>
> 70mm???  For what, if you're going to have 100%VE at 12000 rpm?  What
> rpm
> will the motor go to?  I'm guessing you'd need somewhere in the low 50mm
>
> range.  Smaller is better as long as its not a restriction because if
> you go
> too big the throttles just end up becoming an on/off switch.  For a 2L
> NA
> engine going to 8500 rpm and making ~300hp, we found that 52mm was the
> smallest that we didn't lose any hp.  Anything bigger than that didn't
> gain
> any hp at all and just made the engine more difficult to drive.
>
> >One could run the shafts on bare aluminium, but that's not very
> >durable. If the runners are close together, 4 bushes is sufficient.
> >You'd gain nothing (except profit) by using ball bearings or by
> >chroming the shaft. More bearings than necessary increases not just
> >the expense of the bearings, but also aggravates alignment.
> >
> >No seals are required on the shafts as the shafts are inside the air
> >distribution box. The only part of the throttle actuation that
> >requires a seal is the Bowden cable entry.
>
> You'll have to be VERY careful about thermal expansion of the engine.
> This
> is without a doubt the most difficult part of this entire system.  You
> need
> to make a setup that holds the butterflies aligned within the trumpets
> or
> else they will bind up.  This seems trivial, but it really requires some
>
> attention.  I would put a pair of ball bearings on each butterfly and
> join
> the butterflies from cylinder-to-cylinder with fittings that allow some
> axial growth.  http://www.zeromax.com has some neat couplings that can
> get
> this job done well.  I haven't used them, but they really look like the
> perfect part for this application.
>
> Just wondering though, but why don't you just make a normal-ish intake
> manifold and mount the intercooler away from the engine?  This is
> normally
> much easier to do and you don't have to worry so much about heat soak
> from
> the engine getting the IC hot.  You're also talking about mounting
> something
> big, heavy, and with very little thermal expansion (as long as you keep
> the
> water cool that is) on top of a somewhat high vibration environment that
>
> goes through wild temperature swings, expansions, and deflections.  Its
> just
> a recipe for a part thats going to be difficult to make last very long.
>
> If you go through and make it, I'd love to see some pictures!  Just
> curious
> also though, what rpm range, boost range, and displacement are you
> planning
> for this V6?  I believe you mentioned a 650hp goal...
>
> Kevin
>
> _________________________________________________________________
> Get your FREE download of MSN Explorer at
> http://explorer.msn.com/intl.asp
>
> ------------------------------------------------------------------------
> ----
> To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the
> quotes)
> in the body of a message (not the subject) to
> majordomo at lists.diy-efi.org
>
>
> --------------------------------------------------------------------------
--
> To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the
quotes)
> in the body of a message (not the subject) to majordomo at lists.diy-efi.org
>
>
>

----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org