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Old 06-29-2014, 02:17 PM   #5
joema
Senior Member
 
Drives: 2015 GTI DSG Autobahn. Previous: 2010 GTI APR Stg2
Location: United States
Join Date: Feb 2014
Posts: 109
Quote:
Originally Posted by mstoochn View Post
Hello MK7 Folk,

I understand the performance package offers a hydraulic locking torque vectoring limited slip diff, but what is the standard offering on the car?
The base Mark VII GTI and Golf R use XDS+ to control left/right wheelspin. This selectively brakes the spinning wheel, transferring torque to the opposite wheel.

The VAQ differential in the Performance Pack GTI uses a single Haldex-type clutch pack to essentially brake either spinning front wheel. The overall principle is similar to XDS+ but uses a clutch pack which can be finely modulated. VAQ is computer-controlled, so the ECU can evaluate all other vehicle sensors and decide how best to use VAQ vs XDS+ vs stability control.

The VAQ can transmit 100% of engine torque to either front wheel, vs a Torsen-type LSD which can typically only transfer about 75% of torque to the non-spinning wheel. Likewise a conventional clutch-type LSD has an even lower bias ratio, often equating to around 62% torque transfer.

The Golf R uses a similar Haldex-type clutch pack to modulate front/rear torque, but left/right torque uses XDS+ just like the GTI.

The VAQ diff on the PP GTI looks very impressive. It is proven faster on the race track. I suspect in various sporty street situations it will feel more natural than the non-PP car, mainly when accelerating hard in a sharp turn. However the improved Mark VII XDS+ works fairly well in many street driving situations.
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