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TB with four levers

UdoR wrote:

@Malibuflyer I assume you mean the Turbo Comanche setup I’ve shown above? It is a manually operated wastegate for a turbonormalized engine.

What’s the advantage with a manually operated wastegate over a fixed wastegate? That you can save wear on the turbo when you don’t need an MP higher than ambient pressure?

Last Edited by Airborne_Again at 02 Dec 13:46
ESKC (Uppsala/Sundbro), Sweden

Dimme wrote:

It releases the mighty mouse.

That is hilarious!

Fly more.
LSGY, Switzerland

Airborne_Again wrote:

What’s the advantage with a manually operated wastegate over a fixed wastegate?

Replacing potential mechanical failure by human failure?

Germany

Dimme wrote:

mighty mouse

As it’s a Piper you’ll need some Monterey Jack; for TB21 either Camembert or (for high altitude use) Comté.

EGHO-LFQF-KCLW, United Kingdom

Airborne_Again wrote:

What’s the advantage with a manually operated wastegate over a fixed wastegate? That you can save wear on the turbo when you don’t need an MP higher than ambient pressure?

Evolution was other way round: First there was the manually operated wastegate in GA airplanes, installation of turbos started there in the 60ies. Then presence of human error showed, that it’s not a good idea. Thereafter you had the fixed wastegate, which could not be operated terribly wrong but didn’t have the output power, until the automatic wastegate was invented.

If, however, a manually operated wastegate is used as intented you can save fuel and wear and in addition gain higher output power than the competitors. The fixed wastegate is fixed to some intermediate value, like 50% closed. The manually operated can be opened entirely, and closed completely, thus explaining that the Turbo Comanche should have takeoff power up to 20.000 feet (called Turbo Critical Altitude). Additionally I can run “oversquared” also at altitude, thus more economic.

But yes it is yet another item on the checklist.

Last Edited by UdoR at 02 Dec 15:42
Germany
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