Effectiveness of RAM induction?

[Bruce]

You may be missing one huge element of that design.
With that meter, and depending on the ecm they probably are using that tract
lenght as an element in the accleration enrichment strategy.  With a set up
like that you basically don't need any AE.  Take a real short intake tract
and you'll want alot more AE to get the response back.   If you want real
crisp throttle response that's the realm of short tracts and MAP.  The MAP
system uses a heavy amount of AE related to MAP changes, which is just more
lag free then a MAF.

There is a huge amount of response to be gained with opening up the intake
tract, UNTIL you run out of AE.  On my own car, I went from about 22" of 3"
to 14" of 4" pre turbo ducting, and it made a world of different.   For
every 1% reduction of intake tract resistance you can generate 2% more HP,
but it takes huge changes to make a 1% difference.  Stuff like this is when
you really need to know what is going on in the ecm.   I'd say with all I've
done with relocating the MAF, and plumbing changes I've made almost a 2%
change, in restriction (4% HP).

If I was going to want to make any really serious changes to cure the ills
you have I'd really be looking at finding out all there is to find out about
that ecm, possibly reverse engineering it, or switching to an ecm that is
totally hac'd and perferably fully commented.

Now with that said, you can start thinking seriously about what you want to
do.  While shorting the tract lenght is a great deal, going up in diameter
is really as much or more of an aid.   Then you also need to remember, that
standing still and moving are entirely different situations.  You HAVE to
have the engine compartment, chimney effect for fresh air, or you MAT temps
will be insane, and dropping at MAT temp is really difficult.  This is where
having an open under hood area makes all the difference.  BTW, Ford had some
great little under hood electric air fans that they used in the 6 cyl
pickups for just that reason
Bruce






----- Original Message -----
From: "Diehl, Jeffrey" <jdiehl at sandia.gov>
To: <diy_efi at diy-efi.org>
Sent: Friday, October 12, 2001 2:25 PM
Subject: RE: Effectiveness of RAM induction?


> That seems fair.
>
> The car in question is an MR-2, which is a mid-engine rear drive, Toyota 4
> cyl.  In factory trim, the engine is transverse mounted on the passenger's
> side and the TB is in the center.  From the TB, the intake makes 2 90
degree
> accordion bends and enters a flapper-type Air Flow Meter.  From the AFM,
it
> has a 1 foot long tube that leads to the air filter box.  From the air
> filter box, there is a tube which traverses the width of the car back to
the
> passengers side, up the rear quarter panel to a vent in the side of the
car
> behind the passenger's door.  All told, about 15 feet of intake tube.  My
> car sucks air through a damned STRAW!
>
> On common intake mod for these cars calls for removing the 2 90 degree
bends
> and mount the AFM to the TB and the air filter to the other side of the
AFM.
> Now the air filter is inside the engine compartment and is sucking HOT
air.
> Remember this car is mid engine and there is no real way to cool the
engine
> compartment.  This modification is known to produce 5hp on an engine with
> only 112 before.
>
> Now here is what I'm planning to do...
> From the TB, I'll go through a hot-wire MAP.  I'll have to build a circuit
> to make the MAP look like the AFM for the ECU.  From the outside side of
the
> MAP, it's going to trumpet out to about 8"x6" and bend up toward the top
of
> the engine compartment.  This 8x6 intake box will come up through the
engine
> hood, where the air filter will mount.  Then I'm going to have a duct,
which
> is hinged over the rear window.  This duct will continue from the air
> filter, up and over the rear window.  I'm toying with the idea of having
the
> duct trumpet out yet some more to about 6" height and 36" wide, right
above
> the passenger compartment.
>
> I think this system will remove most of the restriction present in the
other
> systems.  It will get cold air.  Depending on the thermal qualities of the
> material used, (ceramic coated?) I should minimize the amount of ambient
> engine compartment heat that gets transferred to the air.  I've also
opened
> the system up quite a bit, instead of having to breath through a
tube/straw.
>
> So, if I build this system, should I see any RAM effect.  I drive down the
> street at 30mph and stick my hand out the window and feel my hand pushed
> back.  At the TB, the air is traveling at about 55mph @ wot.  But at the
end
> of the trumpet, the intake are is only traveling at a fraction of this
> speed.  I should see ram benefit at above this speed, right?
>
> Thanx for any input.
> Mike Diehl,
> '87 MR-2, 7age, Dual Pipes, hand-bent header.
> '96 4-Runner, Bone stock.
> '90 Corolla, Disguised as a Geo Prism!
>
>
> > -----Original Message-----
> > From: Bruce [mailto:nacelp at bright.net]
> > Sent: October 11, 1999 9:00 AM
> > To: diy_efi at diy-efi.org
> > Subject: Re: Effectiveness of RAM induction?
> >
> >
> >
> > So many different versions of what people call Ram Induction,
> > you'd have to
> > mention exactly what your talking about.
> > Bruce
> >
> >
> >
> > From: "Diehl, Jeffrey" <jdiehl at sandia.gov>
> > Subject: Effectiveness of RAM induction?
> > > How effective is ram induction?  I've heard claims as high
> > as 25%.  I've
> > > also heard people say that it's only effective at 150mph...
> > > Care to discuss it?
> >
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