DSG is awesome

[BossFox]

Nissan do a pretty nice twin clutch DSG style box too... even if it is only a 6 speed.

[logiclee]

Nissan do a pretty nice twin clutch DSG style box too... even if it is only a 6 speed.

If i remember correctly the VAG 6DSG wet clutch and Nissan's GTR dual clutch are very closely related as they are both Borg Warner designs. The Nissan box uses the same control system, clutch mechanism and gear selection mechanism as the VAG box.

VAG are phasing out their wet clutch boxes due to economy and emmissions. Not really a concern for the GTR though.

[philhoward]

It's all about weight and efficiency. The killer of fully automatic transmissions used to be a) the additional weight and the slip in the torque converter; TC slippage being used to get round the lack of ratios. Now they are able to apply torque converter lockup much earlier in the rev range due to more ratios (no more slipping upto 10-15mph on stationary start) and on more ratios, the efficiency of "conventional" (epicyclic gears + fluid connection) boxes is improving drastically - almost to the point where the traditional "wins" for a manual setup are disappearing.

All IMHO, of course..

[Jabozuma]

Try both then vote again.

The 90kg version you quote handles 700NM of torque, that version is fitted to turbo charged V8 BMW's and Range Rovers. ZF also do 450NM and 300NM versions which are lighter and a 1000NM version which is heavier (Bentley Mulsanne, Rolls Royce Phantom/Ghost etc.)

The ZF8HP45 (450NM) used in most smaller BMWs weighs 76kg.

The 7DSG is rated at 250NM weighs 70kg

The 6DSG is rated at 350NM weighs 93kg

The ZF8HP feels just as quick to change up as the DSG and feels faster on down shifts and as 1st and 2nd up to 1200rpm and reverse use the torque converter there's no jerkiness at low speed. And you don't get the hesitation at roundabouts and junctions like you sometimes get when the dsg decides to change down just when you hit the gas.

I'd choose it in any car over dsg and even over BMW's own dct.

Cheers

Lee

Looks like we are not comparing apples to apples then . You are also right that without having tried one ( I Have not) the final judgement has to be reserved.

The other thoughts I have is still, even with the Smaller ZFH45 despite the unit weighing close to DSG its oil capacity is substantially higher increasing the overall weight and oil churning parasitic losses. Then the complexity of it all, build cost and costs of repair. Cannot say for sure but on paper ZF units look far more complicated and expensive than DSG solutions. I am pretty sure they are smoother at slow traffic, town driving but are ZF units as well performing when driven at the top of the engine performance curve?

[philhoward]

Dare I saw "don't knock it till you've tried it", Jabo? I'm curious to try out the BMW 1-series with the 8-speed unit, having done over 100k with a DSG7 so far.

[Jabozuma]

Dare I saw "don't knock it till you've tried it", Jabo? I'm curious to try out the BMW 1-series with the 8-speed unit, having done over 100k with a DSG7 so far.

Having not tried it the only thing I have is paper specs to go by:). The last 1-series auto I had as a courtesy car was absolutely dreadful. It was a brand new 320i auto last year. Not sure what box it had.

I am. It knocking it really, just discussing specs .

However, I must say I am not a big fan of planetary gear autos and torque converters in general... So perhaps a "tad" biased .

[PulsarET]

Am i right in saying the ZF unit is a traditional auto box with a torque converter?

Edited 27 May, 2013 by PulsarET

[philhoward]

You could always compare it to the 4sp+Overdrive boxes of older times - manual gearbox and a secondary planetary box on the end for good measure!

The last 1-series auto I had as a courtesy car was absolutely dreadful. It was a brand new 320i auto last year.

The 1-series 320i? Impressive..

[Jabozuma]

You could always compare it to the 4sp+Overdrive boxes of older times - manual gearbox and a secondary planetary box on the end for good measure!

The 1-series 320i? Impressive..

Haha, well spotted typo . It was 120i of course

[Jabozuma]

Having not tried it the only thing I have is paper specs to go by:). The last 1-series auto I had as a courtesy car was absolutely dreadful. It was a brand new 320i (TYPO, 120i of course!) auto last year. Not sure what box it had.

I am. It knocking it really, just discussing specs .

However, I must say I am not a big fan of planetary gear autos and torque converters in general... So perhaps a "tad" biased .

[philhoward]

The problem with paper specs is that a marketing department has normally had a hand in it somewhere... Alternatively, you could wait for the totally unbiased comments of a motoring journalist to appear..

[logiclee]

Looks like we are not comparing apples to apples then . You are also right that without having tried one ( I Have not) the final judgement has to be reserved.

The other thoughts I have is still, even with the Smaller ZFH45 despite the unit weighing close to DSG its oil capacity is substantially higher increasing the overall weight and oil churning parasitic losses. Then the complexity of it all, build cost and costs of repair. Cannot say for sure but on paper ZF units look far more complicated and expensive than DSG solutions. I am pretty sure they are smoother at slow traffic, town driving but are ZF units as well performing when driven at the top of the engine performance curve?

Remember most of the oil is for the torque converter and hydraulic circuits. Due to the new torsional damper and agressive lockup strategy the torque converter can be locked up from 1200rpm in 1st and 2nd and locked out totally in the other 6 gears. A few years ago torque converters were only locked out in the last couple of gears at high speed.

Most models with the ZF8HP fitted are quicker and more economical than the manual version.

Cheers

Lee

[logiclee]

Haha, well spotted typo . It was 120i of course

If it was a 120i the it had the old 6 speed auto fitted not the new 8 speed ZF unit.

Cheers

Lee

[logiclee]

Probably the most respected Petrol Head jounalist comparing a dsg equipped audi to a ZF8HP BMW.

The problem with paper specs is that a marketing department has normally had a hand in it somewhere... Alternatively, you could wait for the totally unbiased comments of a motoring journalist to appear..

[Ootohere]

He may be respected by many, but his world is not the same as mine.

I have driven the RS3 and it was amazing & i have owned a S3 and it was good and very drivable.

I have driven the BMW tested there, and not being a driving god, i could not get anyplace as fast or safe in the BMW as in an Audi S3, let alone what the RS 3 is like just to drive quickly but without dramas..

(nothing to do with hyperspeeds just on wet or cold roads)

The gearboxes all work, just about every Autobox in every car works well in 2013 for the type of car they are in,

except what VAG have installed in the (sh)Citigo/Up!/Mii, that is pathetic for this day and age.

The fast track test counts for nothing unless you are buying a track car.

The test needs to be on Cambered UK roads and staying in on your own side of the road while getting around corners quickly IMO.

george

[logiclee]

Am i right in saying the ZF unit is a traditional auto box with a torque converter?

Yep but the torque converter is hardly used, above 1200rpm in 2nd (8mph ish depending on vehicle) the box runs in direct drive mode, there's no slippage from that point and the car drives like a manual/dsg in each gear.

This also eliminates nearly all the usuall torque converter heat and frictional losses that used to give conventional autos poor economy.

Cheers

Lee

[logiclee]

He may be respected by many, but his world is not the same as mine.

I have driven the RS3 and it was amazing & i have owned a S3 and it was good and very drivable.

I have driven the BMW tested there, and not being a driving god, i could not get anyplace as fast or safe in the BMW as in an Audi S3.

The gearboxes all work, just about every Autobox in every car works well in 2013 for the type of car they are in,

except what VAG have installed in the Citogo/Up!/Mii, that is pathetic for this day and age.

george

Depends whether fast or fun is your priority I suppose. I've owned some very quick scooby's in the past and yes they are quick but an MX5 is more fun. You can't beat perfect weight distribution and rwd. I know Chris Harris prefers something more entertaining to drive, he did say the Audi is a blunt tool and would probably be quicker on uk roads in uk weather. Depends what you want.

For me the new one series feels far more alive than the old A3 even at normal speeds, the ride is much more compliant too. Not driven the new A3 sporback yet so can't coment.

The ASG gearbox is a joke I agree, VAG are working on a very small 10 speed dsg to mate to a 600 or 800cc turbo destined for Citigo/Fabia models.

Cheers

Lee

[Jabozuma]

I think there's a point where putting more cogs stops making sense as you are getting into CVT territory - with 10 cogs to swap between clutch work loads must be huge!

[Ootohere]

They are becoming basically 'Constant Variable Transmission',

but thats what the emissions and economy will require.

The boxes being designed and developed and fitted are going on Petrol, diesels and hybrids,

but they are going to be required on the Euro 6 & 7 vehicles which will be dual fossil fuel driving 2 wheels & electric motor driven to the same or the other 2 wheels..

I watched the 'Audi e-tron quattro' on Mobile 1 the grid, that is an amazing vehicle..

http://www.audi.co.uk/audi-innovation/audi-motorsport/audi-r18-etron-quattro.html

george

[philhoward]

The boxes being designed and developed and fitted are going on Petrol, diesels and hybrids,

but they are going to be required on the Euro 6 & 7 vehicles which will be dual fossil fuel driving 2 wheels & electric motor driven to the same or the other 2 wheels..

Another car I've been curious about is the Citroen DS5 Hybrid4 which uses this type of system (on my company car list probably due to the improbable apparent mpg figures). Bit of a rough diamond according to some road tests, so still some work to be done honing those systems. Might have to try one out..

[MartynVRS]

Beaten to it with the M135i vid. That car does come with a manual too so both are good options. The RS3 may be great but lots of the newer Audi's I've driven just feel heavy and a bit too boring. Last Audi I drove was an A5 2.0 TDI Convertible and what a pudding of a car that was! The new RS models do cover ground quickly but it's very safe and predictable. That's not to say the M135i isn't but I'm guessing when "on it" on a good A or B road it would be just as good if not better.

The ZF boxes are supposed to be very good. If they are as quick as DSG I'd be happy to drive one.

[logiclee]

I think there's a point where putting more cogs stops making sense as you are getting into CVT territory - with 10 cogs to swap between clutch work loads must be huge!

The problem as I see it is the driving experience, most people don't like how a normal CVT drives and reliability hasn't been great on some variants. Some CVT's have a "Stepped" gears but they've never really been as smooth as a torque converter auto or as direct as a DSG.

ZF said 8 gears was the correct solution when designing the ZF8HP, more than 8 increased drag losses above what was gained having an extra ratio. For the transverse box ZF9HP the layout meant the choice was 7 or 9 gears and obviously 9 worked out the most efficient, (78kg for 280NM version)

The problem with so many ratios is they need the ability to block change especially on down shifts, that's something VAG will have to work out on the small 10 speed DSG.

To be honest even in the 8HP if you drive in manual mode for fun you only use 6 gears as first is only used for getting off the line and 8th is a motorway cruising gear.

In our DSG cars I only tend to use manual mode off the line as I think they push the revs too high especially in the diesel. The DSG's use too many revs in sport mode too.

10 speed is going to be a bit busy in manual mode.

Cheers

Lee

[MartynVRS]

10 speed is going to be a bit busy in manual mode.

Cars from Fast and the Furious have had 10 speed boxes for years.

[Dexter619]

Cars from Fast and the Furious have had 10 speed boxes for years.

I thought they had 37 gears? and NOS to make them go 400mph!

[logiclee]

Cars from Fast and the Furious have had 10 speed boxes for years.

And nitrous systems that give an instant 600bhp increase.

Cheers

Lee