Torsen tagged posts

Two days ago, Ford announced the all-new 2016 Focus RS, which has more than 315hp from the 2.3L turbocharged 4-cylinder engine, mated to an AWD system.

This effectively puts the Focus RS into the competition with other hot hatches in the market, such as the Subaru WRX STI and also the Volkswagen Golf R. The current 2015 WRX STI is in the sedan form, but we can safely bet the hatchback version is coming very soon, therefore we include it into our discussion here.

Generally speaking, Subaru WRX STI is the most hardcore vehicle for rally purpose, while it has lower refinement; the VW Golf R has the best refinement, but its AWD system is the weakest among the three candidate...

The 2015 K900 and Genesis is a big step forward for the Hyundai Motor Company. Not only because of its superb crash testing performance, but also some key components are all developed by Hyundai itself.

For example the AWD system (called “HTRAC”) are developed in-house, so does the 8-speed transmission. Especially for the 8AT, its design is totally different from the ZF, GM and Aisin units. The Hyundai 8AT uses 4 planetary gear sets and 7 shifting elements (5 clutches, including a one-way clutch and 2 brakes). It is more complicated than any of the other similar units...

In part 1, we reviewed some basic knowledge of AWD system, BMW xDrive and Mercedes-Benz 4Matic system. Now we continue our discussion on Lexus and Audi.

Lexus: the IS250/350 AWD and GS350 AWD are using a planetary-gear center differential, plus a wet-type multi-disc clutch control to act as slip control. This is a very advanced and complex design. Because the multi-disc clutch can be 100% locked, it means Lexus’ AWD can handle the case that even front or rear wheels completely lose traction, than the rest side of the two wheels still have full power. The disadvantage of this design is it is complicated and the parts take space...