Posted for "George Braly" <gwbraly@gami.com>:

 Rick,
 
 We will always be friends.
 
 This is an engineering issue,  not a personality issue.
 
 It took you a while and you had some pretty good experienced and expert help
in your effort to re-baffle your #5 cylinder and some other related baffling
problems.   But after those changes  you finally managed to get your CHTs
under control on that installation, although others were never able to get
theirs  under control in their installations.
 
 However,  you suggest that there is some fundamental difference that causes
turbo-supercharged engines to operate "hotter" that gear/belt driver
supercharged engines.
 
 That concept is simply not supported by the data.
 
 In point of fact, we are able to routinely operate turbo supercharged engines
(properly baffled) at 20,000 feet at 101% (not a typo) of rated torque at
BSFC(min) and keep the CHTs all under 380F - - even on  ISA +30F days.
 
 None of that changes the issue with the fundamental problem I mentioned in my
message.
 
First: I did not suggest there was a one-to-one ratio of RPM to turbo speed.
 
 Second,  your installation does  NOT use a "gear reduction" for your
supercharger as you stated.  You DO use an internal  gear box and pully belt
combination that causes the supercharger to spin at many times the engine
crank speed (as it must to be effective) - - but it always spins at that same
fixed ratio with respect to the crankshaft RPM.
 
 Because of this fixed ratio limitation,  your system requires one to employ a
variable choke at the air inlet to the turbo in order to manage the system.
 
 A supercharger or a turbo-supercharger is just an air pump.
 
 Choking air intakes to air pumps is a notion that is fundamentally
inconsistent  with overall system efficiency.
 
 That is the engineering issue to which I was referring.
 
 Regards,  George