[Johan]

Cracker, it won't work that well in your BMW, but in a trans. with straight cut race gears and dog rings, you do not have to push in the clutch to shift, up or down. All you have to do when up shifting is let off the throttle and select the higher gear, then re apply the throttle, and it shifts to the higher gear with no lag or loss of momentum, just instantaneous gear changing. By letting off the throttle, you matched the rpms that the engine will be running at in the next higher gear. Say you are in 3rd gear at 8000 rpm, you lift off the throttle, and pull the shifter back from 3rd gear position to 4th gear position. As the shifter passes through neutral, the revs drop to about 5000 rpms and as you click into fourth, and press back on the throttle, you have matched the rpms for 4th gear and can run it up to top end.
Now a turn is coming up.
It is a 2nd gear turn and you are doing 180. Better slow down a bit.
Lift off the throttle with right foot as you apply braking with the left foot, eventually STANDING on them ( you can push a brake pedal much harder with your left foot than your right foot, try it some time...)2 seconds have gone by and now it is time to down shift from 4th to 3rd, so ease the shifter from 4th to neutral, now depress the gas pedal and rev up the engine to 8000 as you apply pressure to the shifter towards 3rd gear, and as the revs of the engine approach 8000 the shifter will pop into 3rd at the time when the revs match. Now let off the gas and allow the engine to help slow you down . this all took about another 2 seconds. Now it is time to repeat the down shift but this time it is into 2nd gear. You are still wanting to slow down a bit, but the brakes would be too much, so you can let off them now. This means you can blip the clutch to ease the transition to second, so do everything like before, but take a slight 1" jab at the clutch to take the torque off the input shaft of the trans.
Hit second as the engine revs to 6000 so that you have 3000 rpms to get you out of the corner putting you at 9000 rpms and ready to go back to 3rd as you come out of the corner and accelerate away.Another couple of seconds passed so all of this happened pretty quick.
Now add in the factor of the other cars right in front of and behind you doing the same thing and it gets busy.