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Frenchie
01-03-2010, 11:58 AM
DSG - PDF


VW/Audi/Bugatti/Porsche/Seat/Skoda:

DSG: Direct Shift Gearbox

Workings of the DSG:

The gears are intended to be used in "direct sequence" and cannot be as easily skipped like a manual.
Though it may not be good for a manual to skip from say 2 to 4, it can be done without delay , while the DSG has the next neighboring gears pre-selected, and thus takes substantially more time to execute a shift of more than one gear. This may be done intentionally by commanding two shifts in short frequence, or by hitting the downshift button of the gas pedal .

DSG history: Porsche invented DSG more than 20 years ago, hence the Audi/VW connection as of late.
Porsche stopped using DSG on their cars because of the significant power that their current models put out. (I am not sure they ever used it in production cars, or in large numbers)
Rumor has it that the single clutch model used on the Audi R8 can make its way BACK to the Porsches. A beefed up 2 clutch version to possibly follow.

• Volkswagen:

Models with DSG:
2004+ TDI New Beetle
*Passat
2006 & 2007 GTI & GLI & Jetta 2.0TFSI
2006 **Jetta TDI
2007 EOS
2008 R32
2008 Tiguan CR TDI and 2.0 TFSI (?)
***Turan

*Passat: no current us-spec b6 passat has DSG.

*Euro spec B6 Passat does have the dsg coupled with the following engines:

2.0 140PS TDI
2.0 TDI 170PS
3.2 V6 250PS

**Euro-spec Jettas have DSG coupled with the following engines:

SE 1.4 TSI 140PS 6spd DSG
1.9 TDI 105PS
2.0 TDI 140PS

***Euro-spec Touran also has DSG:
1.4 TSI 140PS
2.0 TDI 140PS
2.0 TDI 170PS DSG

• Skoda:

Models with DSG:

Octavia:
1.9 TDI PD DSG 105bhp
2.0 TDI PD DSG 140bhp

• Seat:

Models with DSG:
Leon/Altea:
2.0t fsi
2.0 tdi 140 ps

• Audi:

Models with DSG (S-tronic):

2006 & 2007 A3/S3
2006 MkI TT
2007 MkII TT

Audi also offers a DSG version of DSG called S-tronic . S-tronic is an Audi marketing term that also applies to the VW 2-clutch DSG.

R-tronic: single clutch in the Audi R8, due to the longitudal engine mount).


• Bugatti :

Models with DSG:
Veyron 16.4 (7 speed DSG)


• Porsche:

Models with DSG:
TBA:

With the recent acquisition of the VW stock by Porsche to keep VW in the family, comes the DSG technology rights.
Porsche were the first to develop that kind of gearbox. Did it a long time ago for motorsport but wasn't feasible for a road vehicle. Fast forward to 2009 they released it for their 911, cayman and boxster models. This was BEFORE it was acquired by VW...

PDK: Porsche doppelkupplung, works better and is faster than the VW DSG.


• BMW:

Rumored 2008 M3 will be offered with SMG (dual clutch version)
1998 BMW E36 M3 SMG

SMG: Sequential Manual Gearbox

• Mitsubishi:

Models with DSG(or comparable)
Rumor- 2008? Evo X

• Nissan:

Models with DSG(or comparable)
Rumor- 2008? Skyline GTR

*On a side note:

Volkswagen doesn't actually make the DSG. “DSG” is a Volkswagen trademark for the technology.

“DSG” is made by a US company called BorgWarner. BorgWarner calls their product "DualTronic". BorgWarner purchased a well-known German transmission company. Also, VW has several other suppliers, depending on torque rating etc. For example, they have a low-torque dry-clutch version of the system that just came out.

Volkswagen helped fund development of “DualTronic” in exchange for an exclusive 5 year deal with BorgWarner on the technology



A deeper look at DSG:

Volkswagen and Audi's Direct Shift Gearbox (DSG)

What it is and how it works

The Direct Shift Gearbox (DSG), also known as the double-clutch gearbox, is a transmission developed by Audi and Volkswagen. What makes it special is that it can change gears faster than any other geared transmission. The DSG can be shifted either manually or automatically. It delivers more power and better control than a traditional automatic transmission and faster performance than a manual transmission.

The DSG is a development of the sequential manual transmission (SMT), which is essentially a fully-automated manual transmission with a computer-controlled clutch. Before we delve into the workings of the DSG, let's start with an explanation of the SMT.


SMT: The control of a manual with the ease of an automatic

Though it has appeared on a few passenger cars, the SMT is widely used in certain forms of racing and is featured on Ferrari's Enzo supercar.

Cars with SMTs have no clutch pedal; the clutch is automatically engaged.

Most SMTs can be shifted automatically or manually, the latter using a shift lever or paddles on the steering wheel. The advantage to an SMT is that it uses a solid coupling, as opposed to a fluid coupling (torque converter) as used in a traditional automatic (including Tiptronic- or manumatic-style transmissions). As with a manual transmission, the SMT provides a direct connection between engine and transmission, allowing 100 of the engine's power to be transmitted to the wheels. The SMT provides more immediate response and ensures that the engine RPMs do not drop when the driver lifts off the accelerator (as happens with an automatic), giving her more precise control over power output.

SMTs can also perform matched-rev (or double-clutch) downshifts: When the driver downshifts, the SMT disengages the clutch, shifts to neutral, and re-engages the clutch. The SMT calculates what the engine RPMs will be in the next-lowest gear based on the current road speed, and revs the engine (and, since the clutch is engaged, the transmission) to that speed. It then disengages the clutch, shifts into the lower gear, and re-engages the clutch. The result is a smooth change with no jerk and no sudden deceleration.

SMTs have one major disadvantage, same as a manual: Power must be interrupted while the transmission changes gears.


DSG: An SMT without the lag

The DSG all but eliminates the lag inherent in SMTs. The DSG is essentially two 3-speed gearboxes with a pair of clutches. When the driver starts out, transmission #1 is in first gear and transmission #2 is in second. The clutch engages and the car starts out in first. When it's time to change gears, the DSG uses the clutches to swap transmissions. The #1 transmission immediately shifts to third gear. At the next change the DSG swaps transmissions again, and #2 shifts to fourth. The DSG's computerized controller calculates the next likely gearchange and shifts the "idle" transmission into that gear. The advantage is the speed of gearchanges: The DSG takes about 8 milliseconds to upshift. Compare that to the SMT in the Ferrari Enzo, which takes 150 ms to upshift. It's also significantly faster than a human: According to Audi, the A3 runs 0-60 in 6.9 seconds with a 6-speed manual and 6.7 seconds with the 6-speed DSG. Like the SMT, the DSG performs double-clutch downshifts and can skip gears (i.e. downshifting from 6th directly to 4th, 3rd, etc).

Driving with the DSG

The DSG uses a traditional P-R-N-D-S shift pattern. It can shift automatically in either normal (D) or Sport (S) modes. In Normal mode, the DSG shifts to the higher gears early in order to minimize engine noise and maximize fuel economy. In Sport mode the transmission holds the lower gears longer in order to keep the engine in its powerband. This is especially useful for turbocharged cars like Audi A3, Volkswagen GTI and VW Jetta GLI, since the turbocharger is only active at higher RPMs. Sport mode also provides more aggressive downshifts with slight accelerator pedal pressure.

Manual mode is engaged by either sliding the shift lever to the side or pulling one of the paddles on the steering wheel. Once in manual mode, shifts are made by moving the shifter fore and aft or using the paddles (which are marked " " and "-"). If manual mode was engaged with the paddles, pulling and holding the upshift paddle returns the transmission to automatic mode, allowing the driver to quickly downshift to a lower gear for passing and then hand control back over to the transmission.

DSG Theoretic Model:

http://z.about.com/d/cars/1/7/k/_/vw_dsg_theoreticalmodel_lg.jpg

DSG Transmission Cutaway:

http://z.about.com/d/cars/1/7/i/_/vw_dsg_cutaway_lg.jpg

DSG Clutch Cutaway:

http://z.about.com/d/cars/1/7/h/_/vw_dsg_clutchcutaway_lg.jpg

by Aaron Gold,
Your Guide to Cars.

JohnnyG
02-03-2010, 01:54 AM
Hey Frenchie my 1998 BMW E36 M3 had SMG

Frenchie
02-03-2010, 10:25 AM
Added - Thanks Mr Gee

Howie
02-03-2010, 10:55 AM
Some corrections:

Porsche have their own "DSG", it's called PDK, or Porsche Doppelkupplung. 2 clutch system which works faster and was released in late 2008 models. I have it in mine and it's way way better than the DSG in my R32 and MKVI TSI.

PDK is now available in 911, cayman and boxster models. The latest offering from Porsche now includes the new 997.2 Turbo, which boasts a 'conservative' launch sequence of 3.5 sec 0-100, but was clocked at a recent test at Queensland Raceway at 3.1 with 11.2 sec 400m sprint. 911 GT3 models remain a 6-speed manual.

Frenchie
02-03-2010, 11:01 AM
Added - Nice addition Howie

Howie
02-03-2010, 11:08 AM
Ah I edited my post after you made the additions :) I notice that the extract from the PDF is fairly old with references to rumoured 2008 models offering twin-clutch automated gearboxes

toadcat
16-03-2010, 02:03 PM
Some corrections:

Porsche have their own "DSG", it's called PDK, or Porsche Doppelkupplung. 2 clutch system which works faster and was released in late 2008 models. I have it in mine and it's way way better than the DSG in my R32 and MKVI TSI.

PDK is now available in 911, cayman and boxster models. The latest offering from Porsche now includes the new 997.2 Turbo, which boasts a 'conservative' launch sequence of 3.5 sec 0-100, but was clocked at a recent test at Queensland Raceway at 3.1 with 11.2 sec 400m sprint. 911 GT3 models remain a 6-speed manual.

That's...fairly quick :O