Hello again,

Speed shifting aka

1) Not dropping revs or using the clutch between shifts
2) Moving shift lever hard/fast enough to beat the synchros

is disaster for a transmission and is not any faster....

upside: you think that you are really fast

downside: broken gearboxes, bent shift rods, chipped gear teeth, broken (worn)synchronizers, unnecessary repair expenses.

If you have a non synchro box like in a formula ford (Hewland) you can shift up and down as fast as you can [I have raced them for 20 years+] In the case of a road car, the trans is designed with synchros NOT to be speed shifted: once you beat the synchros which is easy on an older transmission, the transmission internals take all the torque and your box will fail.

Learn to shift rapidly, precisely and if there is any crunch at all, you are doing it wrong or there is too much internal wear in the box to accept what you are doing. As I've said many times before, do a solo 1 driving school (cheap but good) and learn the RIGHT way from pros: it will be the best money spent on you and your car.....

Hotshoe