"Pro Shift" or "slick shift" modifications do away with the bronze synchros, for cleaner shifts.
Liberty Transmissions further developed the idea for their V8 gearboxes in the early '70s,
and these ideas were offered for VW transmissions very soon after.
Once the Bronze rings are removed, the small teeth on the gears (that are a part of the synchro system), are removed,
and a ring, wth larger more sturdy teeth, are fitted and welded on.
The engagement ring is modified or replaced with one that
has two out of every three teeth removed from its inside.
Normally these larger teeth have a taper on one side to help pull into gear,
and zero or reverse taper on the other side,
to allow easier up shift.
Most common mod is the second gear, but a lot of US racers do 3rd and 4th as well.
First gear is left stock, but normally becmes 'non synchro".
I have found that by using a light clutch disc, that I can shift pretty fast,
but with heavy or multiple clutch discs,
or a gear shift with very fast leverage,
it may be mandatory to prevent a failure in the synchro area.
You are right Grogy, no fun for street use,
because it leaves you with no synchros, and you will do damage trying to down shift.
Also upshift must be fast or else the teeth will be rounded off pretty fast.
westi wrote:That's mad Alan.