Changing gear in an auto with paddle shift query
Changing gear in an auto with paddle shift query
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FM-EVA

Original Poster:

41 posts

95 months

Friday 14th October 2022
quotequote all
Firstly sorry if this is posted in the wrong section, please move if so.

I have a 2012 maserati gran turismo sport 4.7 with the automatic zf gearbox and paddle shifters.

My question is, when driving the car hard in manual mode are you supposed to just keep the throttle open and just flick the paddles, or are you supposed to lift off when you flick the paddles then back on the throttle (as you do in a normal manual)?

If keeping the throttle open and shifting gear, does this add more wear/strain to the transmission system?

Thanks

NDA

25,747 posts

255 months

Friday 14th October 2022
quotequote all
Depends!

I always used to shift my Vanquish (for example) on a balanced throttle - neither accelerating or decelerating. It felt very smooth.

However... a car like the SLS hated being driven like that, very jerky. Keeping the throttle in was better.

I am not enough of a mechanic to know why, but think it's a double clutch thing.

donkmeister

13,059 posts

130 months

Friday 14th October 2022
quotequote all
The ECU and TCU talk to each other. The TCU will say "I'm about to shift up a gear, please cut torque in 3, 2, 1... There, I've shifted".

This communication also allows things to happen such as torque limiting in low gears to avoid gearbox destruction, blipping on down shifts and so on.

So yes, keep it planted. Otherwise you'll confuse the car and get jerky reactions.

Pica-Pica

16,682 posts

114 months

Friday 14th October 2022
quotequote all
anonymous said:
[redacted]
^ This.

Ask yourself, when you are in kickdown, is the throttle pedal fully planted throughout all the gears?
The same answer applies when using the paddles.

Whether moderately or vigorously driving, the auto sorts out where it wants the engine revs to be.

DickyC

58,800 posts

228 months

Friday 14th October 2022
quotequote all
Spend the weekend experimenting with different methods and report back.

kambites

71,599 posts

251 months

Friday 14th October 2022
quotequote all
Some really early single-clutch robotised manual boxes were smoother if you lifted off before changing gear, but anything reasonably modern or anything with a torque converter it makes no difference. The paddle is an input into the ECU of the gearbox to tell it you'd like it to change gear whenever it's convenient for it; the gearbox will go through exactly the same processes (including talking to the engine ECU) before actually changing gear that it would if it was an entirely autonomous gear change.

That's why it's hard to manufacturers to make paddle shifts respond quickly. It's not that the gearbox couldn't change gear immediately, of course it could; it's that there's a whole load of preparation and synchronisation which needs to go on to make the change smooth. Hence you can often remap gearboxes to make them faster, with the side effect of making them less smooth.

FM-EVA

Original Poster:

41 posts

95 months

Friday 14th October 2022
quotequote all
Thank you everyone for the replies and detail included, some really useful stuff in there.

Equus

16,980 posts

131 months

Friday 14th October 2022
quotequote all
FM-EVA said:
...when driving the car hard in manual mode...
Anyone suggesting a lift to smooth out the changes hasn't read this bit properly.

If you're driving hard, just keep the throttle planted - the car's ECUs will do the rest.

Depending on how good the software is, it sometimes helps to lift the throttle as you change up a gear when you're driving on light or part throttle, for instance around town.