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BARknucklehead BARknucklehead is offline
Corrupted by power
Join Date: May 2009
Posts: 55
OK, looks like I cleared up a misconception on my part. Only the 997 uses VTG (variable turbine geometry), not the 996.

As a recap, these adjust flow by altering the air incidence angle upon the turbine. Basically, the 997 Borg-Warner VTG turbo is just a more modern version of the variable vane technology that was piloted in production back in 1989 in the old Chrysler Shelby CSX turbo POS. Older variable turbos were indeed mechanically actuated, but were unreliable in gasoline engines due to high exhaust temps (compared to diesels). The new Borg-Warner VTGs use aerospace materials and thus are very reliable and make great pressure.

The 997 Borg-Warner VTG appears to be computer controlled, but have yet to verify...anyone know for sure?

One other note: apparently "variable vane", "variable turbine" and "variable nozzle" turbos all refer to the same thing.
Old 05-27-2009, 02:40 PM
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