VAG DSG

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Sat 31 Dec 2005 19:39
VAG DSG - machika
Does anyone know why the DSG is not mated to any petrol variants of VAG cars? It would surely improve the fuel consumption, compared with normal torque converter auto gearboxes.

Edited by Avant on 22/02/2012 at 22:01

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Sat 31 Dec 2005 20:10
VAG DSG Gearbox - Honestjohn
It is. In the Golf GTI 2.0T 200PS, the Audi TT 3.2, and Audi A3 petrol equivalents. But it seems to work best with more powerful engines. It's not so good with the 1.9 105PS VAG diesel so maybe that (and the cost) is why it's not offered with lower power petrol engines.

HJ
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Sat 31 Dec 2005 20:41
VAG DSG Gearbox - machika
Thank you HJ, I didn't check all of the VAG cars.
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Sat 31 Dec 2005 22:51
VAG DSG Gearbox - ubidenmark
How does a DSG box work in practice ? Is it a two or three pedal car ? Is it an auto box or a manual or either, selectably ?
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Sat 31 Dec 2005 23:27
VAG DSG Gearbox - henry k
Try this for starters.
May not totally answer your questions but it certainly gets rave reports from many sources.

VW say
Volkswagen Group's Direct Shift Gearbox (DSG) combines the ease of an automatic car with the efficiency and flexibility of a manual.

While a conventional gearbox works with one clutch, the DSG transmission has two - one in gear, while the second has the next gear preselected. When the gears need to shift, the second clutch takes the load, while the first preselects the next gear. The whole process takes no more than three to four hundredths of a second - faster than the blink of an eye!

DSG transmissions also have a 'tiptronic' function, allowing gears to be manually selected. Tiptronic changes have a more 'sporty' feel.

There are several benefits of the system. These include improved acceleration and refined uninterrupted driving. DSG is the first of its kind to feature in a production car, demonstrating Volkswagen Group's ongoing commitment to developing remarkable technology.



Also from.
www.motorbar.co.uk/golfgti.htm

The jewel in the new GTI's crown is undoubtedly its Direct Shift Gearbox (DSG). This terrific piece of high-tech kit is probably the most significant development in transmissions since? Well, since trans-missions were first invented. As smooth as most conventional auto-matic transmissions, DSG suffers from none of their performance losses. Basically, it uses two clutches so the next ratio is always pre-selected and ready to engage before you need it ? all without the need for a clutch pedal. The result is dazzlingly fast gear changes that can either be fully automatic or manually controlled.

Left to its fully-automatic self, DSG performs faultlessly in both normal and sport modes. Gear changes are near-imperceptible. But if it's fast sequential manual gear changes you want, simply move the selector lever across the gate. Shifts are then made by small push/pull movements: forwards (up changes) and back (down changes). Alternatively you can use the easy-to-reach F1-style shift paddles on the steering wheel.
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Sat 31 Dec 2005 23:53
VAG DSG Gearbox - ubidenmark
Erm, right. Two pedals then.

Can I be thick, again, here ? How does it know what the "next" ratio is ? Say it's a 5 speed DSG. In 2, 3 and 4 there are two possible "next" ratios: up or down. Can it anticipate both an upshift and a downshift ?

Use small, simple words for the benefit of your ignorant enquirer please.
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Sun 1 Jan 2006 00:37
VAG DSG Gearbox - henry k
It is a sequential gearbox so it is not possible to miss out a gear.
So you can only change up or down to the next ratio.
Hence it is able, using two clutches, to pre engauge the next ratio whether it is up or down.
As I understand it, the next ratios is always on the other gearbox shaft so with a clutch per shaft it is always ready for your choice of gear.

Others will be along who will soon correct me if my understanding is not correct.
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Sun 1 Jan 2006 07:20
VAG DSG Gearbox - machika
A very interesting discussion. I am at a loss, however, to understand why it wouldn't work well with engines of modest power, as HJ suggests.
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Sun 1 Jan 2006 09:51
VAG DSG Gearbox - Honestjohn
It's a twin shaft transmission with 1, 3 and 5 on one shaft and 2, 4 and 6 on another. Each shaft is separately clutched. Simplistically put, that makes it possible for a sort of pre-selection whereby the next gear up or down on the other shaft can be ready.

HJ
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Sun 1 Jan 2006 09:51
VAG DSG Gearbox - Cardew
A very interesting discussion. I am at a loss, however,
to understand why it wouldn't work well with engines of modest
power, as HJ suggests.


Agreed. Logic suggests, that as conventional automatics sap power, the DSG would have a greater advantage in smaller models with modest power output.

I suspect(as HJ also suggests) that cost is the main factor. Marketing would also play a big part? Restricting DSG availability on the entry models will tempt many buyers to purchase a more expensive model in the range.
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Sun 1 Jan 2006 09:54
VAG DSG Gearbox - jc
Let's just hope that if you buy one you don't have clutch problems!
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Sun 1 Jan 2006 09:58
VAG DSG Gearbox - jc
Isn't it also related to the six-speeds in the Galaxy/Sharan/Alhoambra and Fords with six speeds tho'without the pre-selection facility.All of these use a two-clutch/two final drive set-up.
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Sun 1 Jan 2006 12:47
VAG DSG Gearbox - Honestjohn
Yes, it's developed from VAG's short twin-shaft 6-speed box.

HJ
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Sun 1 Jan 2006 12:57
VAG DSG Gearbox - rjr
Let's just hope that if you buy one you don't have
clutch problems!


I have heard rumours that the clutches cannot be replaced. I would stress that it is a rumour and perhaps someone here will be able to confirm or dismiss it.

The rumour said that clutch failure would necessitate a replacement gearbox and VW are planning to offer refurbished units for £1800.
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Sun 1 Jan 2006 13:01
VAG DSG Gearbox - cjehuk
To add to the info, the gearbox works better in my opinion on Petrols than Diesels. If you try and make a smart move off in a diesel DSG (Touran or A3) then nothing happens for a good second or so, then it moves, over delivers torque because you have you foot even further down trying to get the thing to move and wheelspins/ESP comes in. Petrols don't appear to suffer from this lag, and the Touran is noticeably worse than an A3 possibly due to bulk, possibly due to a more relaxed pattern in the box. Either way it's enough that I wouldn't spend my own money on one, depsite knowing just how they work and the technical merits of them.
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Sun 1 Jan 2006 14:38
VAG DSG Gearbox - Honestjohn
I had the opposite experience to cjehuk in the Touran and Golf Plus 2.0 TDI 140 DSGs. I thought the box was smoothing out the torque 'spike'. But maybe the difference between our two experiences is a difference engine to engine, just as there is a difference between the power and torque delivery of the PSA 2.0 HDI 136 in 'my' C-Max and 'my' 307SW. Turbodiesels always have varied. There could be a huge difference between two 1.9 XUTDs car to car.

HJ
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Tue 3 Jan 2006 09:45
VAG DSG Gearbox - machika
(was a thread problem. ignore this post)
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Tue 3 Jan 2006 19:54
VAG DSG Gearbox - daveyjp
If you try and make
a smart move off in a diesel DSG (Touran or A3)
then nothing happens for a good second or so, then it
moves, over delivers torque because you have you foot even further
down trying to get the thing to move and wheelspins/ESP comes
in.


Have to disagree after owning my A3 TDI DSG since May and 14,500 miles. The car doesn't 'do nothing for a second or so' it moves off with no fuss or wheelspin - if you want a quicker take off use the 'S' mode on the gearbox - this 'bites' the clutch quicker and improves throttle response. In all my time of ownership I have had one incident of wheelspin and ESP intervention and this was a couple of weeks ago leaving
a very greasy and damp uphill junction. 'Smart move off' indicates taking a chance to go for a gap which may not be there.

Avant - any other questions about the 2.0TDi DSG combination I'd be happy to answer!
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Wed 4 Jan 2006 09:16
VAG DSG Gearbox - colinh
Agree with daveyjp.

Had a Golf 2.0 TDI DSG since August - 11,000 km - overall 49 mpg. No delays, wheelspin, or ESP intervention. Still amazed at being in 4th by the time you've crossed a road junction.

Interesting that 25% of GTIs are ordered with DSG - being a "driver's" car.
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Wed 4 Jan 2006 09:21
VAG DSG Gearbox - jc
That shows that at least 25% are "image" cars not "drivers" cars.
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Wed 22 Feb 2012 12:19
VAG DSG Gearbox - Jethro
If you try and make >> a smart move off in a diesel DSG (Touran or A3) >> then nothing happens for a good second or so, then it >> moves, over delivers torque because you have you foot even further >> down trying to get the thing to move and wheelspins/ESP comes >> in. Have to disagree after owning my A3 TDI DSG since May and 14,500 miles. The car doesn't 'do nothing for a second or so' it moves off with no fuss or wheelspin - if you want a quicker take off use the 'S' mode on the gearbox - this 'bites' the clutch quicker and improves throttle response. In all my time of ownership I have had one incident of wheelspin and ESP intervention and this was a couple of weeks ago leaving a very greasy and damp uphill junction. 'Smart move off' indicates taking a chance to go for a gap which may not be there. Avant - any other questions about the 2.0TDi DSG combination I'd be happy to answer!

Have to agree with daveyjp. The DSG box is u/s at pulling away quick from a standing start. I have one matted to a Jetta 1.4 160bhp twin charger which can be dangerous when pulling out of junctions.

Jethro

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Tue 3 Jan 2006 01:50
VAG DSG Gearbox - Malcolm_L
The concept of the DSG gearbox is fine but don't believe all the hype - check out the new Passat emission figures on the VW website.

The 2.0 140 diesel with DSG box has 12% more CO2 emissions compared to the 6 speed manual, not a huge difference but enough to move the VED from D to E which will hit your pocket as company car driver.

Factor in the extra cost of the DSG car compared to the standard manual and it starts getting expensive.
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Sun 1 Jan 2006 15:35
VAG DSG Gearbox - Avant
"To add to the info, the gearbox works better in my opinion on Petrols than Diesels."

This is always a potential problem with diesel automatics as well, as with a manual you give it a few revs when starting from rest. My 2.5 TDI is almost powerful enough to overcome this but the slight pause is just still there.

As HJ says it can vary from engine to engine - there are some petrol engines which have very little oomph low down. I'd imagine that an Alfa or Fiat would be best as a manual. If I can't afford another Audi next time I would certainly look at the Golf 2.0 TDI with DSG: if anyone else has experience of this combination that would be interesting.

It's also worth bearing in mind the mileage of the car you're trying: VAG diesels take a good 10,000 miles to loosen up fully and give of their best.
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Wed 4 Jan 2006 12:50
VAG DSG Gearbox - Dr Rubber
There is a software fix for the DSG if lag is excessive. I understand this does not always work, and not all dealers know about it.
Apart from the (occational) lag, I have heard this box is well worth the money if you are after an autobox
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Wed 4 Jan 2006 13:12
VAG DSG Gearbox - cheddar
>>It's a twin shaft transmission with 1, 3 and 5 on one shaft and 2, 4 and 6 on another. Each shaft is separately clutched. Simplistically put, that makes it possible for a sort of pre-selection whereby the next gear up or down on the other shaft can be ready.>>

How does it cope if you are barrelling along in, say, 3rd with 4th preselected however just before it is about to change to 4th you slam on the brakes to make a turn that requires 2nd, I assume there must be some delay in gear selection to the extent that even if it has selected 2nd by the time you have made the turn there will have been zero engine braking available.

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Wed 4 Jan 2006 13:40
VAG DSG Gearbox - daveyjp
Unfortunately it can't legislate for bad driving which is what your example appears to be a result of.

If it's in fourth and you slam on the car selects a gear suitable for the speed you are going once gas is reapplied and how much gas is applied - in this case it could be third or second. BTW it can be in fourth by 25 mph.

Gear delay is 0.02 of a second - substantially less time than it takes to perform a manual change so any lack of engine braking is negligible.
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Wed 4 Jan 2006 15:37
VAG DSG Gearbox - cheddar
Not bad driving, simply an example of a situation where the gearbox would not know what gear would be required next, nevertheless you have answered the question. Just one point, is the 0.02 sec the time it takes to change to a preselected gear or the time to select a new gear.
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Wed 4 Jan 2006 19:36
VAG DSG Gearbox - daveyjp
In the interest of advancing my knowledge of this gearbox and to see what did happen with Cheddar's scenario I did it on the way home (on a deserted road BTW!). Accelerated to the point where it was on the cusp of 3rd and 4th and slammed on. As soon as the speed dropped the display moved back to 3 then down to 2 - I then applied power and with no lag accelerated away. I also slammed on from 50 as I approached a set of lights and the display simply went down the numbers as speed dropped off, it then choose the correct gear for when I pulled off.

In the 0.02 of a second it does both - changes gear and pre selects the next one.
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Thu 5 Jan 2006 22:07
VAG DSG Gearbox - hillman
There is an article in the January 2006 BBC Focus magazine about the Bugatti supercar, W16 engine, 1001hp, 1-100kph in 2.5 sec, 253 mph, with a DSG gearbox. Discuss
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Thu 5 Jan 2006 22:12
VAG DSG Gearbox - Imagos
That must be the Veyron. I'd have thought 1000hp would blow it to bits.
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Fri 6 Jan 2006 08:52
VAG DSG Gearbox - daveyjp
There's enough eletrconic wizardry to prevent you being too enthusiastic! Throttle is e-controlled so flooring it makes no differnce to the performance - it will give enough to get the car going but prevent serious damage.

Saw a friend last night who is swapping a Fiat Multipla (when they start dying in the outside lane of the M60, leave you stranded on the central reservation then the dealer charges you £60 to say there is nothing wrong it's time to get rid!) for an Altea 2.0 TDi DSG - he's not picked it up yet, but he was still grinning from the test drive and that was last Friday!
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Wed 22 Feb 2012 15:48
VAG DSG Gearbox - dieseldogg

Despite wor DSG being in for major & e-x-t-e-n-d-e-d surgery (under warrenty thankfully)

I really like what it does, there is sometimes a fractional pause when pulling away, and the blinking nuisence of having to put der right foot on the brake when trying to get the throttle when moving off from neutral....gerrr.

But "her be a hoot" once moving.

Seems to work really well with the wee 1.6 TDI

50mpg (brimmed figs) overall from mixed driving in an automatic aint bad

It drops instantly from 7th to 4th and fills the clock if tramped at about 45 or 50mph

Excellent for overtaking.

Most of the time sits at about 1500rpm if driving at sensible speeds.

"atta girl"

And Erm.................................................

its available with the 1.2TSI (=petrol) as far as I am aware

Edited by dieseldogg on 22/02/2012 at 15:49

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Wed 22 Feb 2012 16:04
VAG DSG Gearbox - John F

Another disadvantage which might already have cost you 2006 posters dearly is that it has to be serviced! Special fluid and filter replacement not cheap. That makes me very happy with my sealed for life unburstable 14yr old ZF 5HP19.

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Wed 22 Feb 2012 22:00
VAG DSG Gearbox - Avant

I wasn't a moderator in 2005/6 but if I had been I'd have tried to discourage people calling it, effectively, the Direct Shift Gearbox Gearbox. At least I can alter the thread heading.

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Thu 23 Feb 2012 10:05
VAG DSG Gearbox - dieseldogg

Cor

Not like OHP pins?

Or even Ben Nevis

Wot had an old PSI spluttering when i were a lad in the RE (TA)

The Ordance Holdfast Pins pins that is

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