Gear ratio's

[Japper]

It seems from other threads that it could be that DSG has different ( lower ) ratio's than the manual on the 2.0 TDI. Meeting up with Cheechy last week certainly proved this as he could get an indicated 75mph from 3rd while I can only get 65mph.

I posted ratio's for the DSG in an earlier thread, but can not find details on the manual box, anyone know what they are ?

Strange that if Audi put lower ratio's in to give a quicker 0-60 than the manual, for publicity reasons, why they claim slower 0-60 in brochures /ubbthreads/images/graemlins/noidea.gif

Also this must have an impact on fuel economy unless 5th and 6th are same as manual.

 

[h5djr]

Looking at my ETKA details it seems that at least 3 different DSG gear boxes have been used for the 2.0TDI A3. These are codes GYN, HBQ, and HLE. My particular model has an HLE fitted.

As the DSG can only be ordered as a complete item it does not give any details of the gear ratios involved.

No details of actual gear ratios are given for the manual box either. These can be dismantled by a dealer but the gears are only referred to as gear 3 etc.

I will keep looking... maybe some of the road tests in magazines have given the gear rations.

 

[h5djr]

I have found a test in Autocar from March 2003 of the A3 2.0 TDI and it gives the following gear ratio information. Info is gear ration / mph per 1000 rpm:

1st - 3.7 / 5.7
2nd - 2.09 / 10.3
3rd - 1.32 / 16.3
4th - 0.98 / 21.9
5th - 0.98 / 27.4
6th - 0.81 / 33.1

final drive: 3.45 (1-4) 2.76 (5-6)

The car was fitted with 205/55 R16 tyres.

Something not quite right as they quote the same ratio for 4th and 5th ! Probably a typo. Also not sure how you can have a different final drive ration for gears 1-4 and 5-6.

Hope this helps

 

[Amchlolor]

I find 3rd to 4th quite a jump in my car,which makes the fact that the DSG won't let the car 'rev out' all the more annoying.
If I could hold onto 3rd longer perhaps the car wouldn't 'bog down' when it goes into fourth.

 

[Japper]

Cheers Dave, I looked everywhere and must have missed that one /ubbthreads/images/graemlins/ok.gif

So here goes:

Manual / DSG
5.7 / 5.2
10.3 / 8.8
16.3 / 13.8
21.9 / 20.0
27.4 / 26.4
33.1 / 32.1

Next question, Why /ubbthreads/images/graemlins/noidea.gif

 

[Japper]

Other than it answers my question to why the DSG feels and is quicker than manual car.

 

[miketweed]

[ QUOTE ]

Strange that if Audi put lower ratio's in to give a quicker 0-60 than the manual, for publicity reasons, why they claim slower 0-60 in brochures

[/ QUOTE ]

Do they quote lower 0-60 for DSG diesels than manuals? Petrols are the other way round!

I would have thought it highly unusual if it DID have the same ratio's as the manual. The choice of ratios in a manual is a compromise between ease of use/ability of the driver who is controlling the clutch/throttle and performance.

With DSG the engineers don't have to worry about human variance in clutch control and number of gearchanges required, so they can select ratios for performance, fuel economy. comfort etc.

 

[Amchlolor]

3rd to 4th looks better on the manual.

 

[Japper]

[ QUOTE ]
[ QUOTE ]

Strange that if Audi put lower ratio's in to give a quicker 0-60 than the manual, for publicity reasons, why they claim slower 0-60 in brochures

[/ QUOTE ]

Do they quote lower 0-60 for DSG diesels than manuals? Petrols are the other way round!

I would have thought it highly unusual if it DID have the same ratio's as the manual. The choice of ratios in a manual is a compromise between ease of use/ability of the driver who is controlling the clutch/throttle and performance.

With DSG the engineers don't have to worry about human variance in clutch control and number of gearchanges required, so they can select ratios for performance, fuel economy. comfort etc.

[/ QUOTE ]

They dont quote lower times but Autocar had a manual 3dr golf vs DSG 5 dr golf and the DSG was a second quicker to 60, despite having 5 doors.

Thats the confusing bit, if Audi know they're using lower ratio's WHY dont they quote better 0-60 time ?.

Also why is the traction so much better in the DSG rather than manual. If it had been higher ratio's this would explain it, but they're lower so should make traction worse on DSG ?.

 

[Amchlolor]

Autocar's test car could have been a 'press special' Japper.
Woudn't be the first time.
Ford were caught out at the launcg of the latest Mondeo.
They were found to be using non-standard shocks on their press fleet.

 

[Japper]

[ QUOTE ]
Autocar's test car could have been a 'press special' Japper.
Woudn't be the first time.
Ford were caught out at the launcg of the latest Mondeo.
They were found to be using non-standard shocks on their press fleet.

[/ QUOTE ]

Yeah, I realise that and the fact that you get good and bad ones too. But I've driven both and the DSG feels noticeably quicker. Met up with Cheechy last week with his chipped manual and he agreed that the DSG feels 'inbetween' his std. and chipped TDI.

Power is the same with lower gear ratio's and traction not a problem so must be quicker.

 

[jungle]

[ QUOTE ]
Cheers Dave, I looked everywhere and must have missed that one /ubbthreads/images/graemlins/ok.gif

So here goes:

Manual / DSG
5.7 / 5.2
10.3 / 8.8
16.3 / 13.8
21.9 / 20.0
27.4 / 26.4
33.1 / 32.1



[/ QUOTE ]

See what you mean Bowfer - thats a weird jump between 3rd and 4th.

 

[h5djr]

Audi Driver magazine have published another letter this month about the gear rations for the A3 2.0TDI with the DSG gearbox. It's from a Colin Hathway from North Lincolnshire who refers to their reply to my letter about gear rations and puts then right about the ratios of the 5th and 6th gear. Are you a member of this forum Colin?

As they say in their reply the matter was also picked up by Mark Fowler, one of Volkswagen's techical consultants and he confirmed that, with the DSG 'box, first, second, third and fourth are linked on one output shaft, while fifth, sixth and reverse are linked to a second output shaft which has a different final drive ratio.

 

[HeliChris]

Hi All

Forgive my ignorance of the DSG gear box, but my understanding was that 1st, 3rd and 5th are on one output shaft and 2nd, 4th and 6th was on the second. allowing for the pre selection of the next gear.

What you are saying (well the mag and a Vag Tech) is that 1st, 2nd, 3rd and 4th are on one shaft and 5th and 6th are on the other for TDI models.

I can understand the logic behind this, because having the different drive ratio can be used to offset the potential of a TDI damaging the box with the toque it generates.

The gearbox would still be DSG, dual shaft gearbox, but would not offer the same level of performance gain offered by a petrol configuration because it could not pre select gears.

This might also explain the disappointed comments from some members of this forum about the TDI/DSG gearbox.

Chris.

 

[h5djr]

The DSG 'box is the same for all models. The is nothing different for the TDIs. Not sure about the exact design and layout of the various gears but you are correct about 1st, 3rd and 5th being covered by one clutch and 2nd, 4th and 6th by the second clutch. I think looking at a diagram I have of a DSG, 1st, 2nd, 3rd and 4th are on one shaft but it is a split shaft with 1st and 3rd linked to one clutch and 2nd and 4th to the other. 5th, 6th and reverse are on another shaft with 5th linked to one clutch and 6th to the other.

Click here for a link to the article I have showing diagrams of how the various gears work.

 

[southpaw66]

I think there is a little confusion on names. The 'output shafts' of the dsg are 1,3,5 and 2,4,6. But after these shafts is the final drive ratio (and shaft) of which there are two; one for 1-4 the other for 5-6. This is true for petrol and diesel.

 

[HeliChris]

I think there is a little confusion on names. The 'output shafts' of the dsg are 1,3,5 and 2,4,6. But after these shafts is the final drive ratio (and shaft) of which there are two; one for 1-4 the other for 5-6. This is true for petrol and diesel.

I stand corrected, the input shafts (i.e. connected to the clutch) have 1,3,5 and 2,4,6 on them, but the output shafts have R,5,6 for one final drive (i.e. connection to the diff) and 1,2,3,4 on the other.

Thanks for the PDF, alls clear now

Chris.


P.S. I hated rebuilding gearboxes anyway, it was the only job I used to have done for me when I modified cars.