930 turbo comperssor nut ??

[jeos]

Hello.

how many NM. compressor nut (17) must be tightened??



John

[lucittm]

The correct torque depends on the strength of the material or the "Property Class" and I don't know the property class of the turbo shaft or the nut. However, reviewing the torque values for a M6x1mm thread, the Maryland Metrics table MARYLAND METRICS -- TORQUE VALUES CHART shows a value of 4.5 Nm for a class 4.6 fastener and a value of 23.8 Nm for a class 14.9 fastener.

Conservatively, I would think the shaft and nut of a K27 turbo would be equal to or exceed property class 8.8 and the maximum torque for that class is 12.1 Nm.

Of course you would have to rebalance the rotating assembly if it was disassembled. A turbo shop would probably have the correct torque specification.

Mark

[mark houghton]

Originally Posted by lucittm

The correct torque depends on the strength of the material or the "Property Class" and I don't know the property class of the turbo shaft or the nut. However, reviewing the torque values for a M6x1mm thread, the Maryland Metrics table MARYLAND METRICS -- TORQUE VALUES CHART shows a value of 4.5 Nm for a class 4.6 fastener and a value of 23.8 Nm for a class 14.9 fastener.

Conservatively, I would think the shaft and nut of a K27 turbo would be equal to or exceed property class 8.8 and the maximum torque for that class is 12.1 Nm.

Of course you would have to rebalance the rotating assembly if it was disassembled. A turbo shop would probably have the correct torque specification.

Mark

I did some research awhile back on turb rebuilding, and came up with two pieces of information as follows: Torque to 105 inch-pounds (right at about 12 Nm as Mark has already mentioned). I had also read somewhere to torque to 26 inch-pounds initially, then turn the nut an additional 90 degrees and call it good.

[Roby466]

I am pretty sure that my turbo rebuilder told me 105 inch-pounds as well.

[jeos]

Thanks for your help


regards John