Turbo mode from a post builder post is probably not practical - and would require advanced postbuilding experience to set up. On the other hand a tcl post (editing tcl directly) would probably be more straight forward (to implement turbo mode.) There was some discussion in the "old forum" (they archived the forum about a year ago) and if you are able to search there - I would do that.
The main points that I recall:
1) Best suited for Fanuc output
2) From Variable Browser:
mom_kin_is_turbo_output value of TRUE or FALSE
Defines whether the post will use the special turbo block templates and ignore all custom commands for Linear, Circular and Rapid moves. A special custom command needs to be imported from POSTBUILD/pblib/custom_command/ directory. Turbo mode will optimize post-process performance by a factor of 5.
Note: I think you could tailor the motion output a little with special block templates. However - I don't think they ship this file any more. It was called "PB_CMD_init_turbo.tcl"
The link is one up from here - called "GTAC Customer Forums Archive". You won't see it unless signed in. Once you hit the link - your search will be through threads from last year to many years (maybe 15) back. There are a lot of discussions in those threads that may never come up again.
To search the old bbs archives for "turbo" : http://community.plm.automation.siemens.com/t5/forums/searchpage/tab/message?filter=labels%2Clocatio...
To create a post using turbo, in Post Builder, set the controller to User's, and browse to mach\resource\postprocessor\mill_3axis_turbo.pui.
You will now see the custom command init_turbo_output in Start of Program.
Also - take a look at the bottom of this thread (now that Mark found the turbo example) - it shows the special blocks that turbo mode uses (thanks to those guys figuring it out.) I still wonder if there are any kinematic possibilities other than 3 axis (probably not.)
This one also sheds some light:
Turbo mode is fairly sensitive to its limitations. If you deviate from the intent, the post will still run but not at turbo speed. For example, I modified circular radius output to R instead of IJK and the post ran at normal speed. I managed to get away with a little bit of customization but not that one. You have to play around a bit to find out.