Why not a 7 speed DSG?

[drummerdimitri]

Don't tell me its because the 7 speed DSG cannot handle the torque of the engine. The RS Q3 and the new RS3 both have a 7 speed dual clutch so why does the S3 only have 6 gears?

It also has very low gearing so you cannot cruise at say 60 mph with the engine turning at 2000 rpm in 6th gear correct?

 

[quinnii]

My guess would be due to the low torque that the S3 engine produces at low revs, seven speed boxes are usually reserved for Diesel engines. Just a guess though

 

[drummerdimitri]

My guess would be due to the low torque that the S3 engine produces at low revs, seven speed boxes are usually reserved for Diesel engines. Just a guess though

That's not true. I have 3 benzes that are all petrol engines and have the 7 speed automatic transmission.

Also, the S3 makes 280 foot pounds of torque from 1800 rpm so how is that little low end torque?

 

[quinnii]

That's not true. I have 3 benzes that are all petrol engines and have the 7 speed automatic transmission.

*usually*

There are instances like with the BMW's and some seats I think...

 

[JordanQuattro]

7 s tronic is for larger size higher torque cars. 6 s tronic is for slightly less torque cars. 7 s tronic fwd is for low torque small size cars.

Large high torque have the ZF8S box, i.e bi TDI and v8 Bi turbo and Q7.

I'm sure @veeeight will be able to provide a more technical response, he might even be able to give torque limits for each box.

 

[Richy_C]

Maybe don't buy an S3 then.

 

[h5djr]

The biggest difference between the existing DSG/s-tronic gearboxes is that the 7-speed is slightly smaller and is a dry-clutch version. The 6-speed is the original wet-clutch version which can handle a greater torque level. My 2.0TDI-184, and the S3 produces 380Nm of torque and the 2.0TDI-150 produces 320Nm which are all above the limit of the 7-speed gearbox. Diesel engines generally produce much more torque than petrol engines but the 1.6 TDI-105 and all the other petrol engined A3s produce less than the 300Nm torque limit of the 7-speed so that version is used. It's down to the torque output of the various engines which gearbox is used.

 

[glospete]

But I think the OP is not talking about the dry clutch 7 speed DQ200 box but the wet clutch 7 speed.

 

[15audis3]

I would guess because the 6 speed dq250 has been around the longest and is well tested + matched to this engine. The 7 speed wet clutch supporting higher torque hasn't been around as long, and probably costs more to make.

 

[veeeight]

Further up the scale:

RS4 & RS5 have S-tronic
RS6 & RS7 currently have tiptronic (ZF box) - too much torque for current S-tronic to handle.

The 7 sp DQ500 (550 Nm) is relatively new, but if needed for that torque, will probably replace the 6 sp once the costs come down

 

[drummerdimitri]

I was referring to the 7 speed DSG used on the S6 for example. Is it not a superior unit to the 6 speed in the S3?

 

[S3Alex]

For anyone asking these questions,a couple of useful threads here...


http://www.audi-sport.net/xf/threads/uprated-dsg-clutches.232114/

http://www.audi-sport.net/xf/threads/meteor-grey-s3.67106/

 

[h5djr]

I was referring to the 7 speed DSG used on the S6 for example. Is it not a superior unit to the 6 speed in the S3?

The s-tronic used in the S6 is designed for a longitudinal mounted engine which Audi use for the A4 upwards. The A3 has a transverse mounted engine and uses the same MQB platform and a lot of the same components as the Golf 7, including the same DSG/s-tronic gearboxes which are made in a VW factory. I doubt if Audi will develop a different DSG/s-tronic when there is already one available within the group. It had to develop an s-tronic for longitudinal engines as there was nothing already available as VW use all transverse engine, even in the new Passat. If VW decide to develop a 7-speed DSG that can handle a higher torque level than the present one, no doubt Audi will use it as well.

The new A4 due out later this year will retain the longitudinal engine and some models with have an Audi developed 9-speed s-tronic.