|
Message
There is likely some loss in the long TB barrel- I think it is
about 4 ½” long. My barrels are 44 mm dia. What are
yours?
I had measured them to be about 1-5/8, which
is probably 42 mm. Each barrel feeds a single runner that's also
1-5/8" ID. That runner later splits into two to feed the two ports of the
rotor. I could put a small plenum between the TB, and the runners,
to allow each runner to pull from both barrels, but I can't see how that
will do much for me.
You can see my plot of MAP vs RPM at http://members.cox.net/alg3/Dynamometer%20test%20report.htm
and
scroll to near the bottom. It went all the way down to 25” at 7000
rpm. I’d be interested in what TWM has to say.
Thanks for the link
Al. I've tested this with nothing ahead of the TB, so I can't blame it on
any upstream restriction. I looked back at some old numbers, which were
with a larger 44 mm TWM TB, and I was only getting 27 inches or so MAP at WOT
and low altitude. That makes me think, even more, that the low MAP numbers
are a result of the port placement of the TB. I doubt I'll be able to call
TWM today, and I further doubt they'll be willing to admit to any problem
if there is any, but I'll let you know what they say.
Rusty (off to Panama
City)
|