22 replies to this topic

[djned]

http://www.autosport...rt.php/id/58375

ok, so the name might be self-explanatory. but...is this new? who has it already?

[Chubby_Deuce]

Everyone on the pointy end of the grid, and Honda.

Even Williams has it. I think the only teams without it are Spyker and the Red Bulls.

It's fairly new. McLaren was the first to use it, IIRC, in 2004/2005. It basically is two gearboxes in one, with two clutches. One shaft has 1,3,5,7 and the other has 2,4,6, allowing you to engage one clutch as the other disengages. I believe the selector mechanism sits between gears, neutral if you will, so you can go up or down.

[AFCA]

Originally posted by Chubby_Deuce
Everyone on the pointy end of the grid, and Honda.

Even Williams has it. I think the only teams without it are Spyker and the Red Bulls.

Williams was probably the first to come up with it I think. Red Bull will debut it in Barcelona, dunno about STR, Spyker doesn't have the money for developing a gearbox like that I'm afraid...

[kNt]

It's not that self explanatory, as H. Marko doesn't get it is not a Continously Variable Transmission.

[Chubby_Deuce]

What do you mean by that?

Nevermind, read the article.

[kNt]

"Apart from Spyker, all the teams are driving with continuously variable transmission," Marko said in an interview with Red Bull's website.

^ That's not true, seamless =/= CVT.

[glorius&victorius]

is there some technical picture, schematic view of this thing? How come its not on wikipedia ??

[Timstr11]

Originally posted by glorius&victorius
is there some technical picture, schematic view of this thing? How come its not on wikipedia ??

This gives an idea:http://www.zeroshift.com/index.htm

[Chubby_Deuce]

Originally posted by glorius&victorius
is there some technical picture, schematic view of this thing? How come its not on wikipedia ??

http://en.wikipedia....-clutch_gearbox

What Tim posted looks a bit suspect.

[peroa]

Twin clutch is banned...

[Timstr11]

Originally posted by Chubby_Deuce

What Tim posted looks a bit suspect.

Why?

[Tenmantaylor]

CVT is nothing to do with seamless IIRC.

CVT is continously varying transmission- think williams tried it in testing 94/95 with DC and it got banned straight away. He said he couldnt tell how fast he was going. The engine was kept at a certain revs and the gearbox did all the work to maximise power output regardless of speed (so you dont get caught between gears).

Seamless shift just eliminates the engagement time between gears but still requires the same rev range as non seamless.

[Bloggsworth]

Great fun CVTs, you could drive a DAF 33 as fast backwards as you could forwards................

[carbonfibre]

My mother used to own a Daf with CVT and she would win every traffic light battle so to speak.;)

And no seamless shift isnt CVT, it just a very fast gearbox, almost not delay anymore.

[100cc]

Originally posted by Tenmantaylor
think williams tried it in testing 94/95 with DC

Yeah there's video of them testing it. I can see how it would confuse a driver.

[Chubby_Deuce]

Originally posted by Timstr11
Why?

There's nothing of substance on that entire page..

[SpamJet]

As far as I know its a way of changing gear without losing speed.

[rgagne]

Actually, the best description of what it does i heard so far is: it allows to change gear without stopping to apply torque...

As for CVT, it has no gears at all, but a belt over to "variable width" pulley... the ratio is changed by widening one pulley while heu... (dawn my english is bad) un-widening the other one.

[Timstr11]

Originally posted by Chubby_Deuce


There's nothing of substance on that entire page..

Nothing of substance?:http://www.zeroshift...5_Zeroshift.pdf

http://www.zeroshift...systemanime.htm
That is if you don't look beyond the home page.
Do you only look at book covers to determine if is of substance?

[Chubby_Deuce]

ah some CAD renderings and a two year old article in Racecar Engineering. My mistake.

How does their system have any bearing on what F1 teams are doing?

[ingegnere]

Originally posted by Chubby_Deuce


It's fairly new. McLaren was the first to use it, IIRC, in 2004/2005. It basically is two gearboxes in one, with two clutches. One shaft has 1,3,5,7 and the other has 2,4,6, allowing you to engage one clutch as the other disengages. I believe the selector mechanism sits between gears, neutral if you will, so you can go up or down.

I think most (if not all) teams are not using two-clutch systems - this would be too heavy and complex for the tightly packaged rear end of an F1 car. Most teams (Ferrari and BMW included) are using a quick-shift design.

In an ordinary manual gearbox, the gear ratios are arranged sequentially (Christmas tree cluster) and, for example, a single dog clutch (used instead of a syncro for racing) is used to select 1st and the adjacent 2nd. This means that in an upshift, the dog clutch has to disengage from 1st and then engage 2nd.

In the quick shift arrangement, subsequent gears are not located adjacent to each other. This way, as one dog clutch disengages 1st a second one is engaging 2nd. Timing is everything for this to work, and work fast - the ultimate goal. If the synchronization is too slow, you don't maximize the time-saving potential of the system. Too fast, and you risk engaging two gear sets and result is a box of broken bits.
The normal development of one of these gearboxes involves pushing the limit of how fast you can shift.

BTW, I just read recently that the first application of this concept dates back to a J. Barnard design for Arrows! Also BTW, here's a link to an interesting article about Barnard's CFRP gearbox housing:

http://www.grandprix...ft/ftpw017.html

[Timstr11]

Originally posted by Chubby_Deuce
ah some CAD renderings and a two year old article in Racecar Engineering. My mistake.

How does their system have any bearing on what F1 teams are doing?

If you search the Technical Forum, you will find several debates about Zeroshift, Weismann Quickshift. They are supposed to be doing the same thing, namely engage gears so fast there is hardly a drop in revs.

FYI. Seamless shift has been in use at least since 2005 season by Honda, which is based on the Weismann Quickshift principle.

[Timstr11]

BAR TO PRESS ON WITH RADICAL 'BOX'
Friday, February 04 2005


BAR have signalled that they intend to go ahead with plans to introduce a radical new gearbox in 2005 – despite question marks over the system’s legality.

According to this week’s Autosport magazine, the Brackley team’s engine partner Honda have developed a ‘seamless shift’ transmission that enables gear changes to be executed with virtually no break in the power delivery.

The system could potentially save vital hundredths of a second on each gear change, yielding a significant cumulative benefit.

But BAR’s ‘mousetrap’ is in danger of being outlawed by the sport’s governing body because FIA technical delegate Charlie Whiting believes the system constitutes a form of continuously variable transmission, which are common on high-performance road cars but banned in F1.

Honda deny that their trick gearbox is a CVT, however, claiming that it does interrupt power delivery, however momentarily.

The Japanese manufacturer’s vice-president Otmar Szanfnauer told Autosport: “In our system there is a break in power so it does not breach the FIA regulations. The system is a lot quicker than before, but it is not a CVT." Source: ITV -Motorsport website