Hi

I have a friend who is a paraplegic and he owns 3 semi auto Beetles, one of them is a rally car with a 1916, dual webbers etc. http://www.clubvw.org.au/rallysprints.htm The semi auto uses a basically a normal Beetle box with 1st removed, a torque converter so it can idle at lights and a vacuum operated clutch which is engaged by touching the gearstick. Semi autos are just as strong as normal manual boxs but the torque converter takes a lot of the shock out of the system.

Not having a 1st gear really saps off the line performance so i have been doing a bit of research and I came across these units made in Korea http://semiauto.koreasme.com/index_product_e.html

Looking at them got me thinking about a making a clutchless bug using a similar system but using VW parts, the gearstick, clutch servo & clutch servo solenoid they could also be used for able bodied drivers so that you could get that F1 feeling everytime you change gears.

Just something to keep you thinking over Christmas, if you dont use it, you will loose it.

1302Steve:thumb


[Edited on 29-12-2002 by 1302Steve]

Why not just find a way to stuff a 091 box into it?

I would be interested in knowing more Steve for sure.

I know it sounds strange but for some reason I reckon that an auto box would actually work better on lose sand and mud. The wheels would produce a more fluid torque to the ground and the driver can keep the revs up easier when neg soft and powdery sands.

Just an idea - it about now 15 guys that know better come in and cut down my thoughts.

There was an Austin car many years ago (late 50s/early 60s) which has a push button knob on top fo the gear stick for a vacuum operated clutch - no clutch pedal. This was a manual with vacuum operated mechanical clutch - not a semi-auto like the beetle has.

It was a dog to drive. The amount of "slip" (the speed of engagement) was fixed, so if you took off slowly the clutch would grab fast and if you took off fast with a lot of throttle, the clutch would slip a lot for several seconds.

Of course these days with electronics it would be easier to have a pressure sensitive switch under the throttle foot so the clutch knew how much power was being used and adjust the slip-time accordingly, but it's not a straightforward task to replace the manual clutch with a vacuum or electrically operated one.

Just for info, the beetle semi-auto has a fixed vacuum "slip" feature too - the clutch disengages fast but engages more slowly to allow for a little slip, but in this case the fixed amount used is fine because the power is fed through a torque converter which has it's own slip-factor, so you get a smooth departure with either low or high throttle.

Bronze, I too like the idea of running a kombi auto in my manx for the beach.
2 main problems tho:
1) Fitting it between the frame horns.
2) Stopping the oil from overheating.

I've seen a manx up here that was running a type 3 auto but from what i could see he had cut out the frame horns and made up a new subframe.
Also an addition of an oil cooler is a must for the transmission to survive.

Graham

Actually, the VW auto has an extra vacuum port drilled into the venturi - when the throttle is opened it opens a valve to release the clutch vacuum much faster on change-up. The manual recomends 0.5-1 second for this adjustment but I find it can be set a little quicker without causing problems.

I think the idea here is sound, but would take a great deal of expertise to produce.

Graham -

I know that Mark (MR930) used to have an auto manx but I haven't really picked his brains too much about how it went on the beach. I know that he had a few problems on a run but I don't think it was attributed to his tranny.

Yes it is an interesting idea, and for anyone who has had fun in the sand would know that the change from second to first when peaking a hill is the difference sometimes between making it to the top of not.

I agree - tranny temps would definately climb - an external cooler would be a must. Perhaps a set up like Wes' is trialing in his baja above the tranny but you would need to shroud it well so to not just transfer the hot air back onto the tranny. Mabey ducting it down the sides or somthing - and of cource you'd need a lift kit for the space to be available.

Happy New Year to all here!