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Message
Now that's more like it, Rusty. I do
find it interesting the you get less rpm with the sceet tubing. I gain
approx 200 rpm when I use it, but that may be because it gets its air from my
chin scoop for the oil cooler and I suspect the prop helps stuff a little more
air in the tube. But, in any case, your RV-3 should do very
nicely with that static rpm - using Tracy's prop I presume?
Yes, still using Tracy's prop. Remember that
my sceet tubing is only 1.75", and there is one for each throat of the
TB. There's also about 3 feet of it per throat at the moment. I'm
actually not surprised that it hurts performance now, but I was surprised that
it didn't help more when I removed it before. At speed, the ram air would
probably equal the extra drag of air in the hose, but we don't want to wasted
the ram air like that :-)
I'm considering a few options. I could re-work
the rad duct to take a 2.5" or 3" sceet tube, then split it into the two
1.75" inlets to the TB, hopefully with some EDDIE tuning in the mix.
I could also try to keep my current two 1.75" sceet tubes, but run them
into a common plenum that both TB throats would draw
from. I think this would be easier since I don't have to rework the
rad duct (say it with me, I hate fiberglass), plus, I have a lot of
expensive 1.75" sceet tubing. Just don't know what to do yet, so I'll
probably spend some significant time staring at the options
today.
A plenum may or may not assist with the
airflow, convention wisdom is that it does, but I think it depends on the rest
of your intake, they have to play as a team or else they can hurt
performance. Be interesting to see what difference it makes.
The only thing I'm starting to worry about now, is the
1.75" OD runners on the new intake (rev-2.1). I just have to wonder if
those are going to be big enough at 7000+ rpm. If I make it to rev-4, it
won't matter :-)
Cheers,
Rusty (taking
my camera today)
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