Xtrac develops cheaper gearbox with similar performance to dual-clutch gearbox

[Dinesh]

http://www.zerotohundred.com/?attachment_id=16599

Anything worth its salt on the asphalt puts its power to the ground through a dual-clutch gearbox. It’s currently the Holy Grail of gearboxes, slashing shift times and fuel consumption at the same time.

Nonetheless, with more parts comes the possibility of more things going south. It’s no surprise that two clutch mechanisms would potentially cost more to repair if something went wrong. In general, DCT’s are more expensive in all aspects compared to their manual and torque converter counterparts.

Transmission specialists Xtrac, one of the forces in transmissions for racing applications, have now developed a technology for gearboxes, the Instantaneous Gearchange System. It utilises a ratcheting mechanism to couple the gear hubs to the main shaft.

It has been under development for two years now by Xtrac with reported race duty thrown in as well as part of the development. The best bit is that this tech would cost less than a DCT, allowing more automakers to adopt the tech and offer it for a lower price.

Source: Gizmag

 

[alantjw]

wow,,, hope my car could convert to this... XD

 

[Lean]

Good to hear that they are producing a Tranmission which is similar to the DCT.

 

[g4i8y0t]

how much cheaper is it compared to a normal dual-clutch box?

 

[A1diablo]

Interesting news from Xtrac. Nice to see technology principles from F1 making its way to road cars.

A comment though on the story. As far as I know a DCT type gearbox is still cheaper than a torque-converter auto gearbox.

A conventional 2 shaft manual gearbox is cheaper than both of them. Thus the benefit of this Xtrac new ratchet type selector box is that it should be only a little bit more expensive than a normal manual but still markedly cheaper than a DCT.

Furthermore the principle behind this Xtrac box is not new. In principle it is similar to what a UK company called Zeroshift was developing for the last few years.

This system is one of the principles in use behind the seamless boxes in use in F1 nowadays. However the Xtrac seamless shift boxes used in HRT, Virgin and Lotus Racing use a dual selector barrel system. Rather simpler in principle actually, to my understanding while the top teams probably use 'ratchet systems' not unlike what is being offered in this box.

Zeroshift, the company I mentioned earlier is now in collaboration with WilliamsF1.

In the news recently Lamborghini announced its own seamless shift box for the Murcielago replacement, which it called the ISR gearbox. The basic principle is probably not too dissimilar from the dual-barrel type seamless system used in Xtrac in F1. However without the 'dual barrel' but mimicking it's effects.

The 'dual-barrel' type is where one selector barrel controls even gears while another barrel controls odd numbered gears (sounds similar to a DCT box so far..) however it uses a standard clutch as opposed to dual-clutch system in DCT and the shaft arrangement is still like a normal manual box where there are 2 shafts (mainshaft and a layshaft). In the dual-barrel seamless box, when a shift is taking place, the gear shifts 'chase' each other. Meaning before one barrel fully disengages 'gear 1', the other barrel is already engaging 'gear 2'. Technically the two gears are momentarily both engaged. While clutch remains engaged at all times.

The problem with Dual-Clutch gearboxes in F1, if it was legal in F1, would be packaging. A conventional 2 shaft gearbox is still simpler, compact, lighter and probably more cost-effective.

These seamless shift type boxes now seem to be the trend due to its simplicity and cost-effectiveness I suspect. Expect to see more manufacturers announcing it.

 

[^pomen_GTR^]

why nobody cares to re-engineer gear selector drum on bikes to be used on car???single clutch unit and sequential gear change....

number of bikes production prove that the old drum-shifter sequential was reliable...


:hmmmm: anyone care to share their tought on this??

 

[alantjw]

erm so the Xtrac gearbox is like F1 means that we don't need to hold down the clutch when shifting gears? is it something like shiftronic something like that?

 

[A1diablo]

erm so the Xtrac gearbox is like F1 means that we don't need to hold down the clutch when shifting gears? is it something like shiftronic something like that?

Yup, thats the whole point of this new development. To have 'seamless shifting'. Shift gears without having to disconnect power (ie. use the clutch) In reality of course the engine management need to adjust power so that transition is smooth.

Those things with 'tronic' at the end of the word are just marketing phrases. They don't all mean the same thing.

Tiptronic by Porsche is actually a normal torque-converter automatic that allows you to intervene gear change.

Shiftronic.. is that by Mercedes? If I recall refers to whats called 'Automated Manual Transmission' where its a manual gearbox with clutch actuation controlled automatically by electro-hydraulics instead of your leg. This is what Alfa's Selespeed, BMW SMG and even Proton Savvy AMT is about. This is what F1 is using but further refined.

While Porsche PDK, VW DSG, Audi S-Tronic, BMW DCT are all 'dual-clutch' types