----- Original Message -----
Sent: Wednesday, July 20, 2005 6:44
PM
Subject: [FlyRotary] Re: I must be
crazy
an A drive on that turbo engine? 46" of manifold
pressure!
Oh my ache'n head.
46? You think I should
cut it back all of 10 PSI? :)
OK. We did discuss
this earlier, but I think it's time.....
How much for the
upgrade to B, and when can I have it?
John
Me and my big mouth - I'll have to figure that out after I get back
from Osh.
Won't be as expensive as a B to C conversion where all the guts are
changed. That's about a kilobuck.
Flight tested the coil replacement and wingtip mod. Also put
a temp probe near the coils to see what it was there. Yikes!
170 F. OAT was about 95 F. Alternator was probably seeing about
the same. I think I recommended 135 F or less for both in the
EC2 installation guide. I think the coil failure was my fault in this
case, didn't follow my own rule. The higher under cowl temps are a
result of the higher coolant temps on the Renesis. See website for
details on this and why this does not mean you have to have a bigger
rad.
FWIW, I recently noticed on Laura's BMW that there is a blast tube
feeding a shroud at the air inlet side of the alternator. Also
noticed that at 130 mph it gets about 8 mpg while the RV-4 gets about 30 at
the same speed, and that's down near sea level. Pretty amazing
efficiency!
The wingtip mod is a keeper. I was too nervous about the coil &
alternator temps to do extensive testing but if the improvement can be noticed
at all, it's a good one. Most improvements are so small that it
takes very careful measurements over several flights to be sure they are
real. If the weather had been cool rather than hot I would not be so
quick to say the improvement was real.
Most speed mods offer very little benefit at climb & economy
cruise settings but this one is different. In fact, the higher the AOA,
the more this one helps. Roll response at low airspeed seems
crisper too.
Tracy (installing cooling plenum for coils &
alternator)