F1technical.net

Apparently the DSG gearbox changes gear at 8ms. The fastest road car gearbox ferrari do is 100ms in the F599.

I always thought an F1 car was about 30ms.

Is the Volkswagen/Audi gearbox quicker than that of an F1 car??

the williams and honda ones are supposedly seamless?

The 8ms quoted isn't actual gearchange since the gears are preselected... so that must be the clutch dis/engagement time. Still very impressive.

Several articles I've read point out that DSG gearboxes:
- cannot skip gears, ie must go odd-even-odd, not odd-odd or even-even
- are slow at actually changing gears, eg 5-4-3 change the 5-4 is fast (switching bank of gears) but 4-3 is slow because must wait until the 5-3 change is complete.

And does anyone know what type of clutch the veyron has? Is it dry or torque converter?

In this month issue of F1racing, there is an article about the new F1 gearboxes, and they're speaking about a 0.015 sec gap for gear change. According to them, it would translate in a 20 sec gain over a GP comparatively to old gearboxes.

joseff you might actually consider driving a dsg gearbox before critisizing

I was playing around with a stamp controller board at school (circuit board with LEDs, programmed through a PC) and I set the LEDs to flash once every 5 seconds for 30ms, literally a case of blink and you miss it, and then you think about what actually happens in that blink.

Along the lines of:
1, Driver presses paddle to change gear.
2, Signal is sent to on board computer
3, Signal sent through to rev gauge and speedo to see if the engine is at an acceptable speed to make that gear change.
4, Signal sent back to computer approving change.
5, Computer sends signal to clutch solonoid which activates removing power from the gearbox.
6, Computer sends signal to Gearbox solonoids which avctivate, punching out the previouse gear and the new one in.
7, Computer checks everything is in place and blips engine revs to syncronise.
8, Final check and clutch disengaged.
9, Repeat any times per lap.
10, Drive fast, win.

Several articles I've read point out that DSG gearboxes:
- cannot skip gears, ie must go odd-even-odd, not odd-odd or even-even

Same as any racing sequential manual gearbox.

Aha, answering myself and adding a bit to DSG info:

http://www.automotive-business-review.c ... D1A509F3DC

Important bits:

Michigan-based powertrain products developer BorgWarner has signed up two new customers for its fuel-efficient DualTronic transmission technology.

One seems to be Mitsubishi, who have announced a dual-clutch setup for the Evo X. The other one is rumored to be "european". Hmmm... BMW?

BorgWarner DualTronic is an industry-first wet-clutch and control-system technology for automated transmissions... fuel economy improvements of up to 15% over traditional automatics...

So... multiplate wet clutch? 15% better than slushboxes, how does that compare to a manual with dry clutch?

As a side note, the DSG-branded Veyron tranny isn't made by Borg-Warner, but Ricardo.

And finally: Yes the DSG can and does skip gears.

The DSG is far the best auto gearbox around in road cars today. Up to half throttle and you wont even feel the change. Full bore you get slight bump as it swops the cogs. You also get launch control fitted to the box for the traffic light grand prix

Tom wrote:I was playing around with a stamp controller board at school (circuit board with LEDs, programmed through a PC) and I set the LEDs to flash once every 5 seconds for 30ms, literally a case of blink and you miss it, and then you think about what actually happens in that blink.

Along the lines of:
1, Driver presses paddle to change gear.
2, Signal is sent to on board computer
3, Signal sent through to rev gauge and speedo to see if the engine is at an acceptable speed to make that gear change.
4, Signal sent back to computer approving change.
5, Computer sends signal to clutch solonoid which activates removing power from the gearbox.
6, Computer sends signal to Gearbox solonoids which avctivate, punching out the previouse gear and the new one in.
7, Computer checks everything is in place and blips engine revs to syncronise.
8, Final check and clutch disengaged.
9, Repeat any times per lap.
10, Drive fast, win.

Tom, this is perfect way to explain the speed of this gearbox's, except point No 5 and7. As I understand there is no use of clutch during gear changes. Changes are so fast that there is no point to use clutch. Same apply to your point No7. Changes are so fast that there is no any use of adjusting or synchronizing revs. If you want to synchronize revs, then you in case of seamless shifting going to loose more time in synchronizing revs then to shift because of rotational masses in engine.
As Joseff sed, you cannot skip gears, ie must go odd-even-odd, not odd-odd or even-even. But this was the same problem with "traditional" sequential F1 gearboxes.

Does anyone have any diagrams that would help explain exactly how the seamless shifting takes place?

3KGT wrote:Does anyone have any diagrams that would help explain exactly how the seamless shifting takes place?

http://www.zeroshift.com/flash/sequence.swf

Sorry, my analysis was based on a standard road car were I think they do use the clutch, otherwise I've been mislead.

I posted already this link to page where you can find some explanation how this gearbox work. this is a explanation of zeroshift gearbox, but principles of work are the same. I hope it will help you to understand the principles.
http://www.hbm.com/company/apps/SEURLF/ ... p_view.htm