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---- Al Gietzen <ALVentures@cox.net> wrote:
>
>
> what I'm trying to do is figure out how to set up my racing beat intake
> without the intake tubes going over the top. the (bearded one) says it will
> work but is only for engines in the 10,000 RPM range and it's not good for
> 6500 -7000. does anyone. have any other suggestions. I will use four
> injectors but what I want to do is keep the profile as low as possible.
>
>
>
> Tony;
>
>
>
> What works and what is optimum are two different things. And what is
> optimum depends on what your criteria are. You'll not know what is optimum
> without putting it on a dyno and trying a lot of different things.
>
>
>
> My first impression looking at that intake is that it appears rather
> massive. That's OK for a road vehicle, but not 'optimum' for an airplane.
>
>
>
> Lynn says: Short systems tend to have very well defined RPM peaks where long
> systems tend to null out well defined peaks, and are thus a bit easier to
> tune.
>
>
>
> I wont argue with that, yet I have a short manifold (see photo) and the
> torque curve, measured on the dyno, that varies only 10% from 2500 rpm to
> 7000 rpm, and is very constant (varies only about 2%) from 4800 to 7000.
> When torque is flat, hp is going linear upward with rpm. Nothing wrong with
> that.
>
>
>
> My conclusion is that if I used a longer tuned induction, I could get a
> bit more power over a particular range near the tuned point. But for me,
> optimum also meant a compact installation, and light weight. My manifold
> for a three rotor weighs 2 ½ lbs, the installation fits well, and power is
> good. I suppose that one can argue that although the manifold is short
> (4.5 flange to flange), the TB barrels add anther 5.5 and the fiberglass
> air plenum maybe adds some more. Maybe it just involves some luck.
>
>
>
> Al
>
Al
Thanks for your reply. You are right optimum is a better word. I can figure optimum once I get it running on the test stand.
Tony
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