Re: "Smart" shifting (was: Torque and low speeds...)

[Paul G <neong@gte.net>]

>>Mostly proven that even a stock '71 up DP bug motor could slip the little,
>>softly sprung, 180mm clutch. If you want stiffer springs on that clutch you
>>will need a bigger vacuum servo to go with it.
>>
>>I'm a Bug nut, but those things are on my list of what to avoid. The T3
>>full auto is not a bad unit though.

>    Actually, for a conversion, the opposite is true. The auto stick shift
>was a very bad match to the VW engine, but is an excellent match to an
>electric motor. You toss the torque converter. The input shaft that remains
>mates with the center from a standard VW clutch plate. You use this center
>to construct a coupler. You install an electric vacuum pump and resevoir to
>feed the original clutch servo. Tie into the wiring from the shift knob with
>a relay that turns off the controller.
>
>    You just move the shift lever to shift. The controller cuts out and the
>clutch in the auto tranny disengages. You let go of the shifter and the
>controller fires up and the clutch engages. "First" gear on the auto stick
>shift is the equivelent of second gear on the manual tranny. Since you never
>use (or need) first gear on a conversion, the gearing is perfect. Also,
>you've eliminated the power-robbing torque converter.
>
>    An auto stick is preferable for a conversion.
>             _   /|
>             \'o.O'              Bill Dube'
>           =(___)=           bdube@boulder.nist.gov
>              U

There will be problems with a 180mm clutch, also that it is softly sprung.
The concept is *great*, the first gear of an autostick is a VW second gear,
you have a power off switch in the shifter, its even compact by design.
However, stock won't work, you will smell the clutch at every light!

You will need a very stiff old Porsche clutch or possibly old Bus clutch.
Hopefully that would work, but all later bugs came with 200mm clutches and
they won't fit in the autostick t-axle. Then you will need a much larger
vacuum can to operate the clutch. You will need to rig up a new soft
release and engage system (that part should be easy as the electric motor
will give more, stock used venturi vacuum to determine release rate).

It could be done. I even like the idea more than most. But it will not be a
direct swap. Redesigning is needed in the system starting with the clutch
and its vacuum can (going in the trash). Perhaps designing this shifter, a
vacuum pump, and larger vacuum can to a standard VW t-axle would be better
(200mm clutch, lots of aftermarket racing units too).

Neon