I
apologize for lack of clarity, causing you to have to re-invent this
theory.
Al
(Also running TWM TB)
That's
now the old theory Al. The latest theory is that you and I are just
kidding ourselves, and the restriction is real. I just wish people like
Bill and Bernie would have the decency to lie to me about their readings
:-)
Our intake designs
are different; so perhaps the concerns are as well. I have very short
runners downstream from the TB, so the MAP reading is very close to what is
seen at the ports. It would be interesting to know what the MAP reading
is near the intake port in a setup like Tracy’s. Whether the
MAP reading at the TWM ports is accurate or not, I don’t know. My 44mm
diameter barrels (1 per rotor) may be a bit smaller than I’d like; but I don’t
think they are causing a significant performance penalty. The MAP
reading is, of course, not the full measure of the charge into the
chamber. There are the pulses and momentum (velocity) to
consider.
It might be good to
have the TB barrel x-section area roughly matched to the port area. I
can’t find my calcs now, but I think the combined primary and secondary ports
on my engine is over 3 sq. in., like maybe 3.5; and the TB barrel is 2.34 sq.
in. So maybe a 20% larger diameter would give better high end
performance, at some expense to throttle response.
I am anxiously
awaiting your definitive data on performance vs TB barrel diameter.
J
Al