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Actually, Rusty. I have always been
fuel injected. My first manifold was using 50 mm twin throat TMW Webber
throttle body (with 4 injectors), a racing beat webber DOE manifold which I flew
on a 86 six port block. I only had one flight on that engine with the new
(longer smaller diameter) manifold before my HALTECH fuel injection system
failed, so did not get a good comparison.
Thanks. I was thinking that you changed
injection systems at about the same time as the intake, but couldn't remember
exactly.
However, on that one flight with
the old engine and new manifold I did note that my rate of climb increased by
300 fpm over the old manifold. Certainly not a conclusive nor exhaust test
and comparison, but enough to convince me to keep the new manifold when I
installed the turbo block.
As good as this sounds, I've learned (the hard way) not to
believe anything I notice on any single flight. While I don't doubt
that you could have had some improvement, one flight is not enough to quantify
it, so I have to remain skeptical.
In just about every theory of induction
tuning I have looked at (and its been quite a few), if they agreed on anything
- it was longer, smaller diameter tubes favored torque at lower rpms and
short, larger diameter tubes favored power at the higher rpms.
This is a good general starting point I guess. I'm
still bummed that I can't run 7k rpm, but it just isn't efficient with the
2.17 drive, and going to the 2.85 would undo the last 4 months of work, plus
some. As painful as it is, I have to draw the line somewhere, but it isn't
stopping me from dreaming about the next rotary powered plane. After the
Airbike, my sights are set on 300 mph :-)
Rusty (too many plans, too little time and
money)
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