What to expect... PSM On/Off

[topgearuk]

Just after information of what to expect if you drive with PSM off in DRY conditions.

I know on my last car, Audi TTR, that this was the first thing you turned off after starting it!!

 

[Guest]

The same as you get in wet conditions, but with more grip.
Donuts will be possible if the tarmac is smooth.

It will take a bit more provocation to get it to slide, but it is possible.
The car will normally understeer a bit first to give you some warning.
Of course braking or lifting sharply above 50 in a corner could make it interesting, but PSM is not infallible and doing this with it on can tax it a bit.

On the road you have to go pretty mad to get badly out of shape, or else encounter diesel, leaves or gravel.

I am not sure there is any real advantage to turning it off, since it allows you to slide it a bit before intervening. If you want to go completely sideways around the roundabouts you will need to turn it off though. Similarly, if you want to leave big black lines when pulling away you will need it off.

 

[topgearuk]

ORIGINAL: Stuart Martin

The same as you get in wet conditions, but with more grip.
Donuts will be possible if the tarmac is smooth.

It will take a bit more provocation to get it to slide, but it is possible.
The car will normally understeer a bit first to give you some warning.
Of course braking or lifting sharply above 50 in a corner could make it interesting, but PSM is not infallible and doing this with it on can tax it a bit.

On the road you have to go pretty mad to get badly out of shape, or else encounter diesel, leaves or gravel.

I am not sure there is any real advantage to turning it off, since it allows you to slide it a bit before intervening. If you want to go completely sideways around the roundabouts you will need to turn it off though. Similarly, if you want to leave big black lines when pulling away you will need it off.

Thanks, sorry forgot to say mine's C4 does that still apply? I would of thought Donuts would be near on impossible, not that this is what I want to do....

The reason I use to turn it off in my previous car is as soon as any 1 of the 4 wheels lost grip it would cut power output of engine when there might of been a momentary loss of grip

 

[garyw]

If pushed in the dry, it can still happily snake up the road. I know what you mean about power being cut, usually when your halfway across a junction. (BMW)
The Porsche system does seem way advanced to others I have tried, and I don't find it invades my driving style too much at all. Only turned it off a few times, when having a 'play'
garyw

 

[Guest]

If youv'e got PSM and it's turned off, it will still kick in if you get into trouble and then switch itself off when the trouble has surpassed. But PSM is only design to reduce the risk of problems occuring. If you push the car too hard PSM on or off it still can't defeat the laws of nature.

 

[Guest]

I would of thought Donuts would be near on impossible

I have not done it in a C4, but have done them in a turbo (Porsche's one, not mine) in the wet. I required very little effort - get the thing rolling in 1st, put on full lock and floor the accelerator - no need to abuse the clutch. If the surface is slippery enough it is quite possible. 4-wheel drive just means that you need a bit more space. Whether you can do it in a C4 in the dry on an average surface, I'm not sure.