Fast gear change

A simple way to win time

A manual transmission vehicle can be made faster also without changing the engine or transmissions. One way is simply to change gear more quickly. Every error in gear change will cost time. But alas, many older cars have plastic joint sockets and bushings totally worn out and loose.

This is why their shift locations can often be skewed. For example, this is a typical mistake in older BMWs. However for racing, a restored original is not a good choice, because switching gears can be easy and comfortable, but the gear stick has to pass through quite a long way. The originals are also equipped with anti-vibration elements like springs and rubber bushings, which make the mechanism looser. By rough treatment under a burst of adrenalin, such gear sticks tend to break down.

Optimized mechanics

For making gear changing maximally accurate and fast, reconstructing the original mechanism is not the best idea. In order to get rid of its old worn-out ball joint, the mechanism should be replaced as a whole instead. A variety of different shortshifters are available, also some made in Estonia. I got the idea to try a rather unusual solution and experiment with the limits of gear changing and with its highest possible accuracy.

I created a gear changing mechanism, which has all its steel axles on needle roller bearings and completely tight joints. Instead of the original 1 : 8, new ratio is 1 : 2.5. The gear knob is nevertheless located on the same height, because a shorter gear stick would look quite odd and using it would require more force. Details of aluminium and steel are strong enough, the axles rely on both ends and the lever will therefore bear even a hard treatment. The mechanism is bolted into an appropriate slot in the transmission tunnel, in the present case it is designed to fit in a BMW’s one. This solution will avoid cutting and wedling the transmission tunnel, which is usually required for installation. The lower bearing fits also onto a BMW’s lever.

A completely different feeling

Now changing gear while driving is quite different from the way it is in a usual car. The lever is stiff and moves only a few centimetres. Because the length of the lever is equal to an original, changing gear is still quite easy, but due to close-set positions requires a firmer pushing or pulling. However the next gear will switch in with the highest possible speed.

One disadvantage of this kind of a shortshifter is that unlike the original, it is attached to the body of the car and therefore needs rigid cushions for the engine and gearbox. These can be made from some hard plastic or aluminium. Of course, the resulting slightly higher vibration may not be accepted by a car used on everyday purposes.