Wastegate adjustment questions, Piper Saratoga PA 32 with TIO 540 S1AD

systemloc

Filing Flight Plan
Joined
Jan 27, 2021
Messages
28
Display Name

Display name:
SystemLoc
I have a Piper Saratoga with a TIO 540 S1AD. It has a pretty simple turbo setup. There is a linkage cable from the throttle butterfly to the wastegate butterfly, so they are directly interlinked. There's no density controller or anything.

In the Piper maintenance manual, it has the below method of setting up the interlink. Your supposed to have a .120" gap in the wastegate with throttle full open, then flight test. If it doesn't make book numbers, in needs further adjustment, but no guidance on how to adjust it. According to the Lycoming Service Instruction 1431 for the same engine, though, they say make sure the wastegate closes at the same time the throttle is full open. This engine is only used on this plane, so it's really weird that Lycoming has different guidance than Piper.

Anyone have any experience or thoughts to suggest why there's a difference here, and is there any harm to just have the wastegate fully close against the factory stop at wide open throttle?

From Piper maintenance manual:
WG1.png WG2.png


From Lycoming SI 1431:
WG3.png
 
A closed wastegate has a gap. You are assuming closed means 100% shut but in reality closed means adjusted to a gap the same diameter as a #31 drill bit.
 
Back
Top