I sent Subaru Australia an email asking them about turbo that comes stock on MY07 Liberty GT Spec B Tuned by STI. Essentially is this a VF-46 turbo and here the reply I got from them.
Dear Mr Hinton,
Thank you for your email to Feedback at Subaru.
The Turbo in your vehicle is known as a 5-Arc Scroll Turbo, the worlds
first five-arc scroll turbo which has been adopted for the turbo
charger. By correcting the flow of exhaust in the compressor, and
improving compressor efficiency, the low and mid-speed torque has been
increased for the MY07 Liberty GT-B, this turbo is the same as all
Liberty GT models, no other technical information has been provided by
the factory in Japan.
We hope the information provided is of assistance.
Kind Regards,
Amanda Burne | Customer Relations Representative
Subaru (Aust) Pty Limited
Level 4, 4 Burbank Place | Baulkham Hills | NSW 2153
f 02 9828 9284