DIY_EFI Digest V4 #85

[Roger Heflin]

On Thu, 4 Feb 1999, Greg Hermann wrote:

> >Re: TC's and manual trans (was: Re: Smooth strategy)
> >
> >
> >
> >
> >>>No way--a two element torque converter is a violation of Newton's laws!!>>
> >
> >>>Regards, Greg>>
> >
> >Greg
> >I don't know much about Newton's laws however I have been under cars for
> >the last 45 years, working mostly on auto trans. so I know a little bit
> >about torque converters. To get torque multiplication in a 2 element TC
> >you need curved vanes plus a  different number of blades (vanes) in the
> >turbine and impeller. There was usually a split guide ring (doughnut) as
> >well. While this arrangement is not as effective as a TC with a stator
> >it nevertheless multiplies torque and is therfore correctly termed a
> >Torque converter.
> >
> >Theo from downunder
> 
> Let's don't mistake slip--lock-up speed  characteristics for torque
> multiplication. If you have torque A coming into the unit on the input
> shaft, and torque B going out of it on the output shaft, For A to be
> different from B, there has GOT to be a torque reaction against the case.
> No way out of it. Otherwise we are talking about a close kin of the famous
> (?) 300mpg carburettor!
>

Actaully I think this is how it works.  The reason it multiplies is
much simpler, rpmin != rpmout.   The easy model is more like 
rpmin*torquein = rpmout*torqueout*efficiency.   I don't believe there
is a torque reaction against the case (except waht is actually
decreasing efficiency).   Basically if rpmout is 10% less that rpmin,
then you could boost torque by an appropiate amount to make the
quation balance out.   Also generally this is probably a max torque
multiplication which may complicate the model above more, but I have
used this model in some program I have written and it is pretty
accurate with street convertors, with the high slippage convertors the
model above does not work exactly right.     It is really no different
that having a gear that multiplies torque except it is less efficent
and somewhat more variable on the multiplications.