Re: CVT's

[Keith Walker <100662.3423@xxxxxxxxxxxxxx>]

>>from the literature i've read, CVTs are always said to be far more
efficient than a manual gearbox, and leaps and bounds beyond a standard
torque-converter automatic.<<

Anything is more efficient than a conventional hydraulic gearbox. Its mai=
n
advantage is a smooth gear change. However, a manual box is quite
efficient, and a lot of losses are due to the diff which is shared CVT ~
manual.

>>You essentially have negligible losses in a belt, and can tune it in su=
ch
a way that you could never do with a discrete set of gears.<<

>>I'm surprised that the Y10 and Punto ran so poorly, but it could of bee=
n
the current state of their design.<<

So were we. We have an auto Maserati 222, which is a tad expensive to run=

and which Charlotte uses as an everyday car, and we were thinking of a
small auto as an everyday car. The 2 short test journeys put us off the
idea. The CVT box in the Punto (only 8000 miles old) and the Y10 is
basically (other than the Honda box) the only one available in Europe. Th=
e
other cars we are tempted with are Renault Clio Zoom (just dropped with t=
he
new model from production) and the Fiat Seicento Citymatic (which now loo=
ks
like it may not come to the UK), both of which are clutchless manual
systems (ie, conventional gear stick but electro-hydraulically operated
automatic clutch). Charlotte cannot drive a manaul at the moment as she
broke her leg badly a few years back. =


>>Besides the problem with power limitations (which has been essentially
solved) CVTs are considered such an advantage, they were long ago banned
from Formula 1<<

They will ban anything in F1.....only trouble is the loss of advertising
space if they restrict the wings any more! Longer term, I suspect a bigge=
r
advantage of elastic band transmissions is noise, with ever stricter nois=
e
limits.

>>I really like the electro-hydraulic manual boxes like in F1, 355 F1, an=
d
the upcomming 156, but I am not sure at the moment this will become
mainstream.<<

Not sure. With very little effort they can be programmed for fully
automatic operation and are far cheaper to make than hydraulic auto boxes=
,
with far less power loss. For CVT boxes, they seem to have got a bad
reputation in the the UK due to the difficulty in repairing them when the=
y
go wrong.

>>I am going to be talking with a few people tommorow that are more fluen=
t
in CVT technology, and hopefully get to take out the Japanese market Hond=
a
Civic CVT ('tiptronic'). I'll tell you what I find out.<<

Please do. However, I am not sure what the advantages are of a tiptronic
change on a CVT box other than personal feel.

>>By the way, do you work for Ford?<<

No, I am a freelance mainframe computer programmer currently working in
Belgium. =


All the best

keith

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