mschuster

Some questions on 991 PTV Plus. So far I have not found much information about its design and capability. I did find information on ZF Vector Drive which might be similar or the same. Maybe someone knows more?

Porsche claims that PTV Plus is an electronically regulated, infinitely variable torque distribution mechanism. Is it similar or the same as ZF Vector Drive described here:

http://www.irs.kit.edu/download/1312...ZF_Handout.pdf

The ZF unit uses two electronically actuated internal disc brake packs, one on each side of the differential. Is the Porsche unit the same? On a PTV Plus car, are rear wheel brakes used at all or is all torque vector related braking done instead with the internal disc packs?

ZF also claims their unit results in a 10% increase in cornering speed and lateral acceleration (page 5 and 32). Does the Porsche unit offer similar gains? 10% seems like a huge gain to me, maybe too huge to believe?

If Porsche does use similar/same electronically actuated internal disc packs, are they a long term wear item and also does the Porsche unit address production variances, running-in behavior, aging effects, and temperature, as claimed by the ZF unit (page 27 and 28)?

Thanks,
Mike

smosier

There is info about it in the link referenced in the "991 - technical information" sticky. You need to be a RL member to click into the link, though.