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Interview with GKN (Focus RS AWD designer)

81K views 315 replies 53 participants last post by  tedsRS 
#1 ·
#7 ·
The latest version of the Twin Ster-system in the Focus RS detected driving situation and driver demand and regulates this optimal torque distribution to each wheel. If the wheel drive is activated,
Twin Ster drives the rear wheels faster than the front wheels
hopefully we can play with the twin ster ratios. not sure whats to gain but it would be fun to excessively drive the rear wheels faster than the front.
 
#9 ·
Imagine thinking how EVO X had the AYC finally.....and then it turns out Evo 9 was the better buy/keep in my oppinion.

If the Focus RS satisfies your wants at the moment, buy it. Usually as they upgrade from generation to generation, things go bad/good.

For example Mk5 GTI was awesome, then Mk6 GTI had undefeatable traction control which sucked, only to move on to Mk7 which had awesome everything but the Interior seems like a downgrade from the previous 2 generations.....

Each generation has its good and bad so just pick the one you like.
 
#14 ·
DSG would make the wife happy. But, not holding breath.
 
#16 ·
Found this info and translation to English, earlier link isn't working for me.



GKN Automotive, the world leader in powertrain technologies, has developed a new version of its twin Ster torque vectoring all-wheel system for the Ford Focus RS. The combination of translation offset and innovative control algorithms provides improved torque vectoring functionality and helped Ford to develop a vehicle with outstanding driving dynamics performance.

The specially developed for the Ford Focus RS Twin Ster technology will be presented at the booth of GKN (H 5.1, B32) at the IAA Frankfurt.

Peter Moelgg, President Engineering of GKN Automotive, commented: "The all-wheel technology and the Torque Vectoring expertise of GKN help vehicle manufacturers in the process of opening up new areas with their models. Especially for vehicles with high performance is the intelligent all-wheel drive to the drive technology par excellence; it is the most effective way the power, precision to bring, efficiently and intelligently to the road. "

GKN was awarded the contract for the Ford Focus RS program only 18 months before the launch. During this time the engineers at GKN the rear axle torque vectoring (RDM) and the Power Transfer Unit (PTU) and the CVJ side shafts have developed and integrated into the front-wheel drive-based platform. To the system in the existing space to "packagen", a deep feature integration of the system components required. The GKN software and calibration teams have jointly developed with Ford vehicle dynamics engineers new control algorithms for the Torque Vectoring system to provide such a drive train with four different driving modes can.

Dr. Ray Kuczera, GKN Driveline Vice President Global Product Technology, said: "GKN is the only manufacturer with the know-how and the ability to deliver these different hardware and provide the vehicle by integrating software and performance calibrations. To provide torque vectoring systems of this quality, it requires engineers to understand the dynamics and have the ability to work together with car manufacturers on vehicle level. The result of this partnership with Ford shows how powertrain innovations affect the driving dynamics and can heave the handling performance to new levels. "

How the system works by GKN
When Ford Focus RS a wheel system GKN with PTU and a rear axle with twin Ster-coupling system is used. GKN's Twin Ster technology can distribute wheel-selective torque to the wheels. This allows dynamic torque vectoring capabilities of the vehicle over the entire speed range.

The latest version of the Twin Ster-system in the Focus RS detected driving situation and driver demand and regulates this optimal torque distribution to each wheel. If the wheel drive is activated, Twin Ster drives the rear wheels faster than the front wheels.

This effect changes the driving characteristics and handling fundamentally. In curves the twin Ster technology allows more agile oversteering and a direct response to the driver's commands. In Ford "Drift mode" distributes the wheel drive system even more torque to the rear axle in order to settle so enough power to the wheels of the RS and to allow a controlled drift through corners.
 

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#17 ·
I find it interesting that GKN Driveline North America is in Mebane, NC. Curious to see what and if they have any involvement with the current FoRS system.
 
#18 ·
This is something I found a while ago and I think it is on the forum already, but not sure so I'll post it


 
#19 · (Edited)
If that picture, st2focus posted, is of the RS unit it may have the electric pump that allows for rear wheel power from a stop. I am hoping they go that route for AWD launches. If they use input shaft driven pump you have to have some speed (or spinning) to engage rear wheels.

Also, I drive right by Mebane on 85/40 every couple months.
 
#20 ·
Another shot of the PTU and Twinster:
 

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#21 ·
Was it not the PTU the weak link in the awd system? From what the GKN engineer said on nasioc it was the PTU and some other part.
 
#25 ·
Further deep thoughts by Jack Handy...

My biggest worry is the RS500. If it comes with more horsepower in the form of revised hardware such as a turbo, mech front LSD, and widebody kit. I'll be crushed. But if I hold out for something that doesn't even happen, that is by far the worst outcome.

Subaru did that with the 2010-2011 WRX, gave the WRX the STi's bulged fenders.

2009 WRX


2011 WRX
 
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#26 ·
Half the reason I'm waiting a year or two. Maybe the RS 500 comes out with a widebody. Also time to work kinks out. Might be that the 16 ends up more desirable than the 17. The 04 to 05 STi changed front diffs for the worse so only time will tell on the RS. I'm hoping this isn't a week point on the RS and that this is a preemptive strike in anticipation of failures.
 
#33 ·
Awesome, still I get a giggle since the write-up mentions Metallurgy which constantly reminds me of Medieval Times.
 
#35 ·
Found this video:

 
#291 ·
I didn't know Louie CK worked at Ford!
 
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#41 ·
These systems will disengage power to the rear if its not needed to help with fuel economy. It should send power to the rear nearly instantaneously if needed. It will use a plethora of sensors and algorithms to determine how much power to send and to where it should go. I'm sure the drive mode also play into it.

Say you're driving down the highway at constant speed. There's no reason to try to power the rear wheels. So the rear will disengage to reduce some driveline losses and give you a slight MPG gain.
 
#43 ·
I forget where but it was stated that very rarely will the AWD system stop sending power to the wheels, and only if the wheel is straight. I think this is still a grey area at this time and hopefully we will have better understanding with in time. It was almost worded as if you have any degree of steering power starts getting diverted.
 
#42 ·
No drive line loss is really removed on the RS. The Land Rover has a system in the PTU to disconnect the the propeller shaft that the RS does not have. So, in RS the front diff and rear spool always turn at or very near 1:1 (unless there is some gearing between the front diff and the proper shaft not yet revealed). The rest of the drive line after the rear clutch packs is always connected to the rear wheels, which while under normal driving are always on the ground. So as the front wheels drag the rear wheels around it also drags the rotation resistance of the rear half shafts, same as on the Land Rover here. On the RS it leaving the rear wheels disconnected is more to prevent the drive line stress between the front and rear when fighting each other so much since there is not center diff or viscous coupler device.
 
#46 ·
I found this video over on the GKN site about the FoRS AWD system:

Disconnecting for Fuel efficiency - GKN Driveline

Disconnecting for Fuel efficiency

Permanent all-wheel drive systems distribute torque to all four wheels on a vehicle. This ensures a vehicle is always ready for an adverse change in traction or terrain; it also significantly impacts drivetrain efficiency and fuel consumption.

Technology developed by GKN automatically recognizes if AWD is required, if it is, drive can be seamlessly connected, to all wheels, or even just those that have traction. If not the system efficiently disconnects virtually all of the AWD components from the drivetrain.

The key driver for new AWD technology is to reduce both fuel consumption and CO2 emissions, while of course retaining the ability to cope with variable traction. GKN allows you to have all the benefits of all-wheel drive, and the efficiency of two wheel drive.
 
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#47 ·
Awesome find! So the drive shaft and everything up to the clutches stop on the RDU when the AWD is not engaged. I like it.
 
#55 ·
Exactly my thought, bro.
I was surprised ppl aren't *****ing about it.
I don't buy this car for fuel economy, I am buying it for performance only, and added comfort feature is good when I have a passenger in car. But performance is my top priority.
If the other driver mode doesn't some how "force" all time AWD, I might pass on this one.
 
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