Future DSG for Subaru ?

[legacy_y_tu]

Anyone hear any rumors or have any thoughts if Subaru will offer this anytime soon. I guess they'd be licensing it from Borg-Warner, which has already licensed it to VW/Audi; although I wouldn't put it past the Japanaese to want to design their own system.

 

I personally would love to see a Spec B WAGON WITH A 6 spd DSG tranny, NAV as an option and a bump to 290HP or so. I'd seriously think about trading up for this!!

[brio11]

We've had heated discussions about twin-clutch technology in the '07 Evolution X on the evom forums. The future will look very bright for it if mitsu can convince the hard to please tuner fanbase. It seems likely that within the next decade most high performing cars on the market including the sti will incorporate a twin clutch trans similar to Direct Shift.

[Scotty]

Screw the DSG. It's a complicated system that isn't necessarily better. The Zero-Shift system is much simpler since it's a modification of a standard manual gearbox and provides instantaneous gear changes by engaging one gear and disengaging the other at the same time without having to use the clutch. It's called Zero-Shift because there is no lapse in time between engaging one gear and disengaging another. It's also completely mechanical with no computers. They are currently adapting it to use a electronically controlled clutch and also tie it into the engine management computer to help smooth out the shift.

[gt_ltd]

^ is it being used in any production vehicle?

[Scotty]

It is not being used in any production cars because this is new techology not 3-5 year old technology like the DSG and SMG. Pretty much everyone in automotive engineering consider this the revolutionary break through in transmission design in the last decade. Most of motorsport, besides those guys that only make left hand turns, will be using it in the near future. Even Ferrari's F1 transmission which is considered to be the fastest in the world at around 20 ms per shift can't compare to the 0 ms shifts. It is a huge benefit in auto racing because it will shift under full load. In the typical Automated Manual Gearbox (AMG) the engine still needs to cut fuel for a brief moment to drop the rpm during an upshift. ZeroShift doesn't need to. The FIA has recently approved of the use of this system in F1. Most of the auto manufactures are looking into it also because it is such a simple system. In fact the system is so simple, it didn't take an automotive engineer to develop it. The guy who invented the system is a washing machine repair man.

 

Here's a G & speed chart of a TVR test vehicle with conventional gearbox.

http://www.zeroshift.com/pics/trace_cerbera.jpg

 

Here's one with the ZeroShift version of the same gearbox.

 

http://www.zeroshift.com/pics/trace_zscerbera.jpg

 

In comparison a BMW M3 w/SMG

http://www.zeroshift.com/pics/trace_M3.jpg

 

And Audi w/DSG

http://www.zeroshift.com/pics/trace_audi.jpg

[melayout]

If the shift is instantaneous that means the RPMs must also drop/rise instantaneously, wouldn't that be hard on the engine?

[legacy_y_tu]

Yeah, I read that the zero-shift system is kind of lurchy (word?) too. Althought that graph you shows certainly doesn't show it (assuming the blue line is G-forces.

 

I also read that the DSG is simpler than a conventional Auto tranny . I'm not sure how, it certainly sounds and looks more expensive since it appears to have more parts. Although if it's true and there is a cost savings to it perhaps we'll see them sooner than we expect.

 

Where's Jon (from CT) he seems to have the inside line into Subaru .

[Scotty]

The initial fully manual version does exhibit a spike in the inertia and a spike in the torque during the change. It does increase stress in the drivetrain and tires. Their ultimate goal is to achieve a smooth shift with no spikes in the acceleration or sudden deceleration like in a conventional gearbox. They are currently working on a variety of ways to decrease the spike by either altering the engine's power delivery for a fraction of a second, a little slip of the clutch, and/or driveshaft dampers. The idea is it's easier to reduce a spike in the torque than to fill the gap left by the clutch in a conventional gearbox.

 

The advantage of this system is, it uses basically a conventional gearbox, the prototype was a modified Borg Warner T-5 gearbox. They are not restricted to using a sequential gearbox like most of auto racing and most car companies did with the AMG's. It is capable of shifting out of sequence like a regular gearbox. It's also much simpler than Audi's DSG since that's essentially 2 clutches and 2 gearboxes and the computer has to do a complicated task of orchestrating the 2 clutches so it slips just the right amount as one engages and the other disengages to make it appear to be a seamless shift.

 

The ZeroShift is expected to be in production by the end of the year.

[brio11]

Excellent graphs, thanks.

 

Btw the technology behind twin-clutch (DSG) has been used in motorsports for 21 years, the consumers are now finally benefitting from the race bred gearbox.

 

I posted this on evom: Twin-clutch started in 1985 when Walter Rohrl successfully tested it in his Audi Sport quattro S1. Since then, the twin-clutch has been used in the ISMA GTO, Rallies, LeMans, etc. There have been many many variations of it, including the DSG trademark we know of now.

[Scotty]

Most of auto racing doesn't use a twin-clutch setup instead using a sequential gearbox with a hydraulic clutch.

 

Now here's the big question. Since Audi had a twin-clutch setup back in 1985, how do you operate it? McLaren didn't come out with a semi-auto gearbox for F1 till the 90's.

[brio11]

Most of auto racing doesn't use a twin-clutch setup instead using a sequential gearbox with a hydraulic clutch.

 

Now here's the big question. Since Audi had a twin-clutch setup back in 1985, how do you operate it? McLaren didn't come out with a semi-auto gearbox for F1 till the 90's.

 

A quick up or down on the lever, thats what I can infer from the cockpit pics of his quattro.

 

Location

4WD

Differential (Front-Central-Rear)

 

Clutch (Manufacturer)

2 plate

Gearbox (Manufacturer)

6 speed (automatic)

1st Major Rally

Olympus 1985

WRC Wins (1)

Italy 1985 (Röhrl)

 

http://gamma.nic.fi/~globe/rally/paradise/pics/b_quattros1.jpg

[Scotty]

Computers in cars really didn't exist back then. So what controls the two clutches? DSG is only possible because you have a computer modulating the engagement and disengagement of the two clutches.

[brio11]

"Both Porsche and Audi have used transmissions based on similar principles in racecars during the 1980s. Porsche's vaunted and incredibly successful 956 and 962C race cars benefited from the Porsche Dual Klutch, or PDK, transmission. In 1985, Audi itself used a dual clutch transmission in the Pike's Peak Hillclimb winning Sport quattro S1 rally car."

 

A clue to your answer:

 

"Serial production of a dual clutch or DSG transmission has been untenable to date due to insufficient means of mechanical (proper clutch actuation requires precise control of the simultaneous engagement and disengagement of the clutches), as well as electronic controls. Audi again proves its technical expertise and prowess by bringing this first-ever commercial application to the streets." Continued. Pikes peak owned by twinclutch batmobile.