flyrotary@lancaironline.net Mailing List Archive

Thanks Lynn;

I'm wondering if I could detect detonation while flying?

I have exhaust temp probes on both rotor exhausts, the turbo is a few inches downstream. The O2 sensor is on the turbine outlet pipe.

Should the intake air charge temp probe be mounted after the throttle body in the intake plenum? I would think so, becuase that is as close to the combustion event as I can get, and also where I read intake manifold pressure?

I wonder how to interperate a pressure differential gage across the throttle body?

-----Original Message-----
From: Lehanover@aol.com
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Sun, Jul 11, 2010 10:00 am
Subject: [FlyRotary] Re: High test and turbos

In a message dated 7/11/2010 12:33:02 P.M. Eastern Standard Time, shipchief@aol.com writes:

Lynn:

DITTO Kelly's request.

I have a 'street ported' 1988 13B Turbo with a Turbonetics 60-1, and Tracy's EC-2 & RD-1 gear.

It's in an RV-8 and is not (yet) intercooled. I have a CATTO 2 blade prop the same pitch & diameter as he builds for a 180 HP O-360 powered RV-8 (left turning of course). I simply extrapolated the rpm from 2700 for the rated 180 hp, to estimate 200 HP @ 3000, which would be a good RPM for the 13b, about 6570 RPM.

I have 1.2 hours ground run time at this time. Cooling upgrades seem to work well, with max rpm during test 3600 so far...

Van designed the RV-8 for 200 HP, so I am building to that as a goal for the initial flight test, but would like to refine the A/C and powerplant as I gain experience, and install a CATTO 3 blade. what power draw would require intercooling, and what kind of safety margins should be considered, like instrumentation, and such? Greg Richter talked me out of waste gates and blow off valves, because they are heavy and complex. He said don't worry about it, unless ground or flight tests demonstrate a need for it.?

Scott E

I really don't know much about turbos. I imagined that I would pick a compressor wheel too big for the application, hoping that the output could never be more than a few pounds no matter the situation. Turbo normalized, sort of. Or a bypass pipe around the turbo, with a butterfly valve operated from the cockpit, so you can dial up any boost you want for take off and cruise.

Generally you can count on the temperature going up X amount for each pound of boost, so most installations include a probe on the inlet of the compressor section. Turbine inlet temperature or TIT. Look for data on General aviation turbo engines to decide how much temperature rise should be allowed.

Lynn E. Hanover