Dual clutch gearbox but with a H-gate
Dual clutch gearbox but with a H-gate
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Discussion

MagicalTrevor

Original Poster:

6,481 posts

260 months

Friday 15th March 2013
quotequote all
I had, what I think is, a great idea...

Inspired by the complaints about the GT3RS and Clio 200 being 'flappy paddle' only I wondered whether it would be possible to have the best of both worlds.

The car would have a dual clutch gearbox (for all the reasons that suit the manufacturer like better emissions and economy) but it would appear to have a H-gate stick. The usual positions would have electromagnets in them and hydraulics or springs for resistance rather than your conventional methods of holding the gear stick in place.

Still with me?

Each of the following modes would be selected using buttons on the centre console.

Automatic mode

Gear positions 1, 2, 5 & 6 would be unavailable (using the magnets). Position 3 would be 'Drive - Forward' and position 4 would be 'Drive - Reverse', neatral would be 'Neutral'.

Paddle mode

Same as Auto mode but you now use the paddles to change up and down with reverse being available by going through neutral into reverse.

'Manual' mode

All positions are available and the car works just like a proper manual gearbox (except no clutch pedal). Simply select the gear and off you go. A change from 2nd to 3rd switches cogs and is quick due to pre-selection. Changing from 2nd to 4th would just effectively like pressing the paddle twice. The main difference is the driver thinks that they have full control over the gearbox like a manual. The gearbox will rev match on downshifts.

Ok, you can't heal and toe, but the majority of people can't or don't do this anyway.

So who wants one? biggrin

Buff Mchugelarge

3,316 posts

181 months

Friday 15th March 2013
quotequote all
Will it break?

MagicalTrevor

Original Poster:

6,481 posts

260 months

Friday 15th March 2013
quotequote all
Buff Mchugelarge said:
Will it break?
Never, it'll be bullet proof. For the sake of conversation, lets assume that it'll last as long as any other gearbox

Dr Z

3,396 posts

202 months

Friday 15th March 2013
quotequote all
I'd still want to be able to rev-match as I think that is a major source of enjoyment for me in a manual car. Actually, I don't care (too) much for a H-gate, thinking about it.

I maybe persuaded if there is a sequential type dual-clutch box, but still with the ability to rev-match manually...Very tough I know.

I should add that, this is in a car with clear performance/sporting intentions. Don't care about autoboxes in econoboxes/daily drivers.

Garvin

5,661 posts

208 months

Friday 15th March 2013
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I'm struggling to understand how this is different from the current Audi & BMW systems .............. except to be slower and more cumbersome in 'manual' mode?

m1dg3

128 posts

185 months

Friday 15th March 2013
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Didn't Saab do this about 15 years ago with a roboticised clutch on a normal gearbox?

MagicalTrevor

Original Poster:

6,481 posts

260 months

Friday 15th March 2013
quotequote all
Garvin said:
I'm struggling to understand how this is different from the current Audi & BMW systems .............. except to be slower and more cumbersome in 'manual' mode?
But it should be as fast, if not faster than a normal manual albeit with the benefits of dual clutch box.

Garvin

5,661 posts

208 months

Friday 15th March 2013
quotequote all
MagicalTrevor said:
Garvin said:
I'm struggling to understand how this is different from the current Audi & BMW systems .............. except to be slower and more cumbersome in 'manual' mode?
But it should be as fast, if not faster than a normal manual albeit with the benefits of dual clutch box.
Yes, but why would anyone want to slow down a dual clutch box?

Wills2

29,846 posts

206 months

Friday 15th March 2013
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m1dg3 said:
Didn't Saab do this about 15 years ago with a roboticised clutch on a normal gearbox?
Sensonic, it wasn't popular.

McWigglebum4th

32,414 posts

235 months

Friday 15th March 2013
quotequote all
The great pleasure of a good manual is not just getting the revs matched but also the feel of the actual shift.

With a caterham 6 speed which is the best gearbox ever it is a wonderfully mechanical feel


I just don't think you can get that unless the lever is moving lumps of metal around in oil

Synchromesh

2,428 posts

197 months

Friday 15th March 2013
quotequote all
Wills2 said:
Sensonic, it wasn't popular.
Someone told me Porsche used to have a similar box (minus the paddles and full auto). Effectively a manual minus a clutch pedal. The clutch was disengaged upon pressure on the stick, but also slipped when pulling away etc. Might be wrong about this though as never seen it myself.

Save Ferris

2,738 posts

244 months

Friday 15th March 2013
quotequote all
Wills2 said:
m1dg3 said:
Didn't Saab do this about 15 years ago with a roboticised clutch on a normal gearbox?
Sensonic, it wasn't popular.
Toyota had this on early Yaris, called Freetronic, it wasn't great.

Manual drivers didn't want it, and auto drivers didn't understand it.

Triumph Man

9,637 posts

199 months

Friday 15th March 2013
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MagicalTrevor said:
...All positions are available and the car works just like a proper manual gearbox (except no clutch pedal). Simply select the gear and off you go. A change from 2nd to 3rd switches cogs and is quick due to pre-selection. Changing from 2nd to 4th would just effectively like pressing the paddle twice...
What you've just described is the gearbox from an old Leyland bus wink

MagicalTrevor

Original Poster:

6,481 posts

260 months

Friday 15th March 2013
quotequote all
Triumph Man said:
MagicalTrevor said:
...All positions are available and the car works just like a proper manual gearbox (except no clutch pedal). Simply select the gear and off you go. A change from 2nd to 3rd switches cogs and is quick due to pre-selection. Changing from 2nd to 4th would just effectively like pressing the paddle twice...
What you've just described is the gearbox from an old Leyland bus wink
Ah, crap! frown

FisiP1

1,279 posts

184 months

Friday 15th March 2013
quotequote all
MagicalTrevor said:
Triumph Man said:
MagicalTrevor said:
...All positions are available and the car works just like a proper manual gearbox (except no clutch pedal). Simply select the gear and off you go. A change from 2nd to 3rd switches cogs and is quick due to pre-selection. Changing from 2nd to 4th would just effectively like pressing the paddle twice...
What you've just described is the gearbox from an old Leyland bus wink
Ah, crap! frown
The enthusiast who moans about wanting a manual transmission over an automatic is the kind of person that will heel&toe I'm afraid, doesn't really help them.

There are already systems like this around too, they just don't find a niche to fit them into the car market.

Enricogto

646 posts

176 months

Friday 15th March 2013
quotequote all
Synchromesh said:
Wills2 said:
Sensonic, it wasn't popular.
Someone told me Porsche used to have a similar box (minus the paddles and full auto). Effectively a manual minus a clutch pedal. The clutch was disengaged upon pressure on the stick, but also slipped when pulling away etc. Might be wrong about this though as never seen it myself.
Yep,

Sportomatic!

http://www.youtube.com/watch?v=zcVQR0p3wEo

Wasn't that popular as well....
Sorry OP, had the same idea but apparently it defies all the real benefits of each solution.

Enrico

Futuramic

1,763 posts

236 months

Friday 15th March 2013
quotequote all
As far as I know the DSG boxes work differently to a conventional manual in that they have two input shafts with odd and even gears on each. Changes are actuated by the first input shaft clutch disengaging whilst the second simultaneously engages.

A conventional manual box uses selector forks acting on sliding dog clutches to lock into the desired gear. A DSG will have two sets of these so the actual change is carried out only by the transition of one input shaft clutch to the other. So for second to third: second gear locked and engine engaged to second gear input shaft with one clutch. Third gear is also locked and turning on the other input. At the moment of change the second gear input is disengaged whilst the third is brought in.

At the same time another gear change happens. Assuming the car is accelerating of course. The second gear input shaft now changes from second to fourth to enable the next seamless change using the clutch pairs. Thus there are two sets of sliding dogs operating independently of one another.

This system would be possible to replicate but would require two levers and an extremely skilled driver. In practice it has to be actuated by either hydraulics or solenoids with computer oversight.

Therefore any H-Gate, as proposed, would be a glorified electronic selector switch. In practice it would be inferior to paddles or a straight pull forward and back lever.

Additionally manufacturers build in over-rev protection. As far as I know DSG boxes have built in safety systems that take over in the event of driver error when working in manual mode, if the driver suddenly decides to change from fifth to first using the paddles or doesn't change up at maximum revs for example. The box will change automatically (or not) to prevent damage to the drivetrain. If this happens the box would end up out of sync with the H-Gate fake selector lever.

Either the lever would have to be motorised and move itself or the dash would have to instruct the driver which gear to select in order to re-calibrate itself. If you've ever played the Daytona USA arcade machine with the rolling start track you'll understand.

M4cruiser

5,238 posts

181 months

Friday 15th March 2013
quotequote all
Trev, your invention is a wonderful and complicated solution, but there isn't a problem. It would be awful. My brain would hurt.

Conventional manual (5 speed is best), or conventional fluid auto (3 speed is nice). That's what works best, to allow the driver to concentrate on the things that matter.

I'm not old fashioned, it's just all about Ergonomics. Modern designers just don't understand.

6-speed manuals and 7-speed autos, with manual overrides etc etc, may be more fuel efficient and so on, but ... something's missing.

skwdenyer

18,707 posts

271 months

Wednesday 20th March 2013
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Triumph Man said:
MagicalTrevor said:
...All positions are available and the car works just like a proper manual gearbox (except no clutch pedal). Simply select the gear and off you go. A change from 2nd to 3rd switches cogs and is quick due to pre-selection. Changing from 2nd to 4th would just effectively like pressing the paddle twice...
What you've just described is the gearbox from an old Leyland bus wink
Wilson pre-selector gearbox. Fitted to a variety of pre-war cars. My Father's Lanchester had one. Talbot-Lago GP cars of the 1930s had them, too.

The OP isn't quite saying that; the reference to 'pre-selection' is due to the dual-clutch set-up - at any time, the 'box has 'pre-selected' a gear either 1 above or 1 below the current ratio. The driver doesn't make that election; the CPU attempts to guess the next move based upon whatever data and 'intelligence' it possesses. The Wilson, on the other hand, provided for a purely manual (pre-sel)ection of the next ratio, which could be any available.

Thinking about it, the Wilson, with a little hydraulic pressure to kick the clutch and transmit paddle instructions to the 'box, could have been made into a 'flappy paddle' set-up in the 1930s smile That would be quite a 'steampunk' sort of thing to do these days smile