AW: Intake manifold construction, intercoolers

Rausch, Bernd br at rnt.de
Tue Dec 4 15:08:36 GMT 2001


Bruce,

I have the information on intercooler size from
http://www.spearcointercoolers.com. The core is 2-171.
 This is a road/track car, and I am going to use two big
radiators(12"x16") to cool the liquid.

The plenum will be made of aluminium, only the runners will be CF.

I do not want to have the air going thru a 4.5 core and then want it to
bend
immediately. This is with the stock plenum without intercooler. My
plenum will be straight, like on my ascii drawing below.

And I do not see flow in a turbocharged application very different from
a n/a. The air is even denser in a turbo application, so flow losses are
higher. Of course you can crank up the boost, but you are loosing
efficiency and going to have more backpressure this way.

Best regards,
Bernd

-----Ursprüngliche Nachricht-----
Von: Bruce [mailto:nacelp at bright.net]
Gesendet: Dienstag, 4. Dezember 2001 15:39
An: diy_efi at diy-efi.org
Betreff: Re: Intake manifold construction, intercoolers



From: "Rausch, Bernd" <br at rnt.de>
Subject: AW: Intake manifold construction, intercoolers
> thanks for your response. Your input (and that of others, of course)is
> really welcome. But I disagree in several points:
> I want to use one Spearco air/liquid intercooler per side (V-engine),
> this IC is 4.5"x4.5"x10" and rated for 700cfm each. The engine will
need
> about 800-850cfm for 650hp.
> With the IC in the plenum, I will actually cool the plenum and gain IC
> area this way (normally with a hot plenum and runners you heat your
> intake charge). I thought about building carbon intake runners, to
> insulate the runners and the plenum from the heat of the cylinder
head.

You going to use a total of 4.5x9x10 for cooling an engine of 650 HP?.
Is this a dragster, or just for really short bursts of speed?.
what are your plans for cooling the liquid?.
CF for a large ehough plenum to hold all this is going to need some
serious
ribbing to prevent a sneeze from rupturing it.

> I want to make big plenums, about 1,5L *after* the core (displacement
of
> the engine is 3L total). So the core will not straighten the flow to
> much.

Your going to have the air going thru a 4.5 core and then want it to
bend
immediately?.  Ugh, OK, I don't see it happening that way, but it's your
decision.

> Think of it this way: If I use the same IC (of which I assume that it
is
> the right size for the application) with a "classic" setup
> (IC->TB->plenum), all I am doing is to avoid the transition form the
> intercooler core to a 2,5" pipe and the transition from the pipe to
the
> manifold (and a 90deg bend, since my TB is mounted on the side of the
> plenum)!

Me thinks your toooo concerned about an elbow.  Is it some really small
radius?.
Again, I think your thinking in N/A terms, not T/C
Bruce

> Best regards,
> Bernd
>
> -----Ursprüngliche Nachricht-----
> Von: Bruce [mailto:nacelp at bright.net]
> Betreff: Re: Intake manifold construction, intercoolers
> Any intercooler that you use in the plenum, would either be too small
to
> be effective, or need fluids that are really cold.  you'll also be
losing
> the surface area of the piping for heat transfer.  With the in plenum
> cooler, you also be exposing it to the heat of the manifold, thru all
it
mounts,
> and you libel to losing alot  of cooling effect to cooling the
manifold.
> For a plenum to be effective the opening intake valve must be able to
draw
> against the plenum, having the finning in the plenum is going to
**straighten**
> the air flow, and so the opening valve is going to have to *try* and
have
> this air change direction, rather then drawing against a rather
turbulent
> chamber of waves, and air movement.  BTW, this is the same set up as
> International Harvester uses on some of it's deisel applications, but
they
are
> extremely low rpm motors.  They also have an area above the I/C that
is
about
> equal to the area below it.  I think you'd have to have a really huge
plenum for
> any kind of free reving motor to really work,  in the IH version they
use
> coolant in the I/C so as to just reduce the high peaks of air temp..
>   I think it's a stop gap measure, and limited in practical
application.
> For a diesel tractor working in the fields it's OK.
>   I had choices of 2.5 and 3.0" piping for the front mount I/C in my
GN,
> and after some investigation think my original thoughts of using the
3"
> are best.  Trading a little off idle / low rpm response for cooler
ultimate
> flow should be worth while.  I'm lucky in so far as mine is an
automatic
> trannied car, so I can tolerate the lack of really down low torque
since
> converter slippage with be absorbing that loss anyway, or rather
allowing
the
> engine to rev thru that zone in a lightly loaded state.
>   Huge preturbo plumbing, large post turbo, as much I/C as can be
> fitted, and calibrate as necessary.   then finalize the hardware to
best
use the
> above.  At least that's the way I'm headed.
> Bruce

> From: "Rausch, Bernd" br at rnt.de
> Subject: Intake manifold construction, intercoolers

> > Thanks for the responses I got, I have some additional questions:
> > At the moment, I have an air/air intercooler per side (twinturbo V
> > engine). I have per side: three 90deg bends, about 2m piping, two
> > intercooler mandifolds with 90deg bends and four silicone hoses.
> > I am thinking of welding an air/liquid intercooler core from Spearco
> > directly in the intake plenum. The throttle body will be upstream of
> the intercooler. With this construction I can exit the turbo in a
straigt
> > line, with an expanding pipe of about 0.4m to the throttle body. I
> will only need one hose (turbo has a flange at the outlet). This setup
will
> > save me five 90deg bends, 1.6m piping, three silicone hoses and two
> > manifolds at the intercooler per side.
> >
> >       TB   IC     intake runners
> >        |---------|------------|
> >        |   ||    |------------|
> > -------|   ||    |
> >  ->    /   ||    |------------|
> > -------|   ||    |------------|
> >        |   ||    |
> >        |   ||    |------------|
> >        |---------|------------|
> >
> > -Is there any downside of this setup ?
> > -How do I calculate intake plenum volume ? Only the volume on the
> > downstream side of the intercooler or the complete plenum including
> > intercooler ?
> > Any help would be appreciated.
> > Bernd
> >
>
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