Thursday, October 02, 2008

Meet the Revoknuckle

We are not used to pure mechanical advances lately but this one is interesting and promising. The revoknuckle concept is used in the new Ford Focus RS in order to deal with the small problem of delivering 300hp to the front wheels. Now an image of the Focus RS could be illustrating this entry but I could only find pictures of some hideous-green coloured unit with lots of wing on it. So let’s keep this more technical hence the revoknuckle bits below.

The problem with all that power in a FWD car is wheelspin and understeer. Those effects can be overcome greatly with the use of limited-slip differential coupled with some good coding of the traction control software. The problem is that the use of the limited-slip differential does not solve the torque steer effect, that is, the influence of the engine torque on the steering on front-wheel drive vehicles. For example, during full acceleration the steering may pull to one side, which may be disturbing to the driver. Ford says it addresses that with geometry changes, new bearings and parts keeping the simplicity of a traditional McPherson strut arrangement, but minimizing steering disturbances and torque steer, mainly due to a reduction in steering offset.

Minimizing is a key word here. Ford does not claim to completely eliminate torque steer so I wonder what effect they have managed. The first test drives should be an interesting read.


Anonymous said...

This is system is exactly the same architecture Renault Sport introduced with the first RS Megane, and has been using in the Clio RS latest model. Not really new nor revolutionary

Anonymous said...

I think the Revoknuckle is being used to eliminate the cons of the LSD, therefore to improve drivability. The revolutionary about the whole undertaking is that a production FWD exceeds the standard of 220-240 hp maximum power for the FWDs. The sport editions of Focus has made a tradition of good handling. I guess the tradition is maintained with the new generation, and with that aggressive look everyone will be teasing you to drive to the limit!!
I guess making it 4WD would raise the price a lot as well as the weight, so why not RWD :-P