Transmission, Automatic

Manual Downshifting

Manual Downshifting

You can down-shift your auto in the same way that you shift your manual in the set up for a corner.

Try this, but before you do remember how smooth your shifting was when you first learned to shift a manual box. At first this will seem difficult but when mastered your auto down-shifts will be lightning quick and sooooo smooth. In the mean time you may care to use another auto box car when learning how to do this and spare the 928 the trauma.

1 drop down a gear with the selector

2 wait

3 blip the throttle to raise engine revs and to signal the autobox for a down shift NOW

4 ease way back on the throttle and match higher revs, to lower gear, to road speed and continue the smoothest downshift ever [seriously]

5 repeat steps 1-4 to drop down a second gear if required

7 balance the car on the throttle - remember, you have around five litres of very flat torque and five litres of engine brake to do whatever you like to the rear end of that car.

8 BWAAAAAAAAAAAAAAAAA!!!!!!! as required.

* on points 2,3 and 4 judgement and feel is required just like it is on a heel&toe double clutch downshift - this is something that takes a little time to learn.

* on point 2 the wait depends on your engine revs and road speed - you can preselect the lower gear and leave the autobox in the higher gear for an extended period. If the engine revs and road speed are all wrong for the lower gear the wait will be protracted or the downshift will not occur unless you rectify the engine rev situation with a big throttle blip and the required injection of revs. Sometimes if you wait long enough the autobox will drop into the lower gear even though the engine revs and road speed are
a long way apart causing partial rear wheel lockup and extreme stress on the driveline.

* don't forget to control the throttle blip; peak, duration and roll-off are the three parameters here. The first two match the engine revs and road speed for a smooth shift, the throttle roll-off at the right time and to the right extent is what stops the car lurching forward and you crashing.[we are slowing for a corner]

** left foot braking makes the whole downshift process so easy and so natural. If you don't left foot brake already and want to learn, do it away from anything that you can possibly run into. It is not something to try for the first time on the way from work in peak hour traffic.
** left foot braking means your emergency braking will start faster and therefore more controlled, have longer to operative be more effective.
** left foot braking allows you to counter the initial understeer of you car that you experience, at say low speed. You will be able to rear wheel steer you car into that parking spot at speeds of about 10KM/h by keeping you foot on the brake to prevent acceleration whilst feeding in some of that juicy low rev torque to the rear wheels to move the rear end of the car out a bit.
*** do not try this unless you really really know what you are doing, otherwise the insurance claim will read 'I accelerated my 310HP Porsche into a car spot because some guy on the internet told me to do it'.
** with the low speed steering be aware that everyone around and in particular your passengers will not know what is going on. They equate engine noise with speed and well, what would you think if you were the passenger being driven into a car space and the driver revved the engine and the tail stepped out? In the case of a roundabout your tail can be jumping around behind the car [say you want to be sloppy for the hell of it] and it will cause most observers to assume you are going very fast, when in fact you are going very slowly.

As I said before it will seem weird at first, it does take time and feel, but I think it may spark a whole new love affair between you and your auto 928.

Have fun, take care!

john kraft

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