how does a Tiptronic gearbox work
 

as above

I think and a very crude description ;)

Try changing gear without using the clutch ;) you need to match the Engine Revs to the speed of the Gear which you are selecting.

Is the car was doing 60mph in 4th at 5krpm to change to 3rd you may have to be at 7Krpm or 5th 3krpm to match engine & gearbox speeds.

If the speeds are different it will be difficult engage the lever even with Road Cars Syncromesh .

The rally Cars gearbox has Hydraulics/Electronic sensors and ECU to cut the power(not sure if Fuel or Ign cut or both) to exactly match speeds and change gear. 0.3 second rings a bell ;)

Tony

Whoops not sure if you meant Tripronic or Scequencial :rolleyes:

Tiptronic is just one branding of semi automatic gearbox

Tiptronic - Porsche
Selespeed - Alfa Romeo
etc...

Essentially it is a manual gearbox with additional systems to change gear, control the clutch and match engine revs to the next gear, whether changing up or down. You usually hit paddles or buttons on to command the system to change up of down, but you can sometimes hit the "gear lever" too.

There would be a number of actuators controlling the shifting mechanism (maybe just one if a sequential gearbox), another controlling the clutch actuation and another on the throttle body so it can match the revs. They use electric actuators for throttle body, but TBH I'm not sure whether they would use electric or hydraulic for the others, probably electric for the shifting but clutch loads may be too high to use another electric actuator there.

the only advantage of the tiptronic gear box is that they can handle more bhp!!!! some US guys running the subaru with 400+ bhps with standard auto box.. hope that helps... :norty:

Tiptronics became well known as they were a popular option on Porsches and are marketted as sporty automatics, but they are not automated manuals.

A Tiptronic is mechanically a standard automatic gearbox (planetary / epicyclic type system) with manual override on the change mechanism. I think they may use electrically operated servos rather than hydraulics and the torque convertor will have electronic lockout, but that's about it.
Yes they are stronger than manuals, but most automatics are. However they are less efficient, slower to shift and still have a torque convertor.

Andy