Good day all

I need your great help and opinions about octy 3 stability issue , as my car and my cousins car suffer a lot from side wind on highway even at speeds as low as 100km ,

Our cars are 1.4 dsg and are delivered with the extra height pack

So my questions:

Could this extra height be the cause of this instability?

How can I return the car to normal height if I want to?

Does more tyres and larger rims help with this or have no effect? Mine is 16inch

Could a lowering springs be fitted to this suspention and work normally or I need to change both shocks and springs ?

Add to the above the steering which have vague center as you know this with the winds makes the car playes on the road as a skate board

If lowering would help I just want to make it the normal factory ground clearance without the extra

The car really frightens us on Highway and I see many lower class vehicles passing me in the same driving conditions normally without suffering.

Thanks very much in advance .

Edited 10 June, 201412 yr by Mohamad

The vague centre is a result on the lane assist. I had the same issue. I turned the LA off and that sorted it.

I dont have lane assist option and dont even have the mode selection option also.

I'm not sure that this "extra height pack" is even an option in the UK, but I'd expect it to consist of longer free length and/or stiffer (higher compression rate) springs and maybe longer dampers to increase the ride height. If I'm right then yes, it will reduce crosswind stability at speed.

 

So you need to find out which parts (springs or springs and dampers) are changed, and buy the "normal versions" instead.

 

Different tyres will possibly increase lateral grip in corners, but not stability.

 

As to the steering, it may be possible to increase or decrease the sensitivity in VCDS, or maybe you're both reacting too fast/much to minor deviations from straight?

I would get the tracking looked at. Mine was a way out after hitting a kerb at speed and the car had a tendency to 'wander' at speed. Doing the tracking transformed the car.

Is changing steering mode can really be done through vcd? Or not sure?

Also sorry for my ignorance but what is tracking??

The extra ride height is called rough road package I think and a guy here have it in his combi I think he is from UK.

Steering weight (assistance) can be changed through VCDS.

 

Tracking is a short version of wheel alignment and only applies to the front wheels, but generally doesn't cover castor and camber angles either.

But as long as me and my cousins car have the same behavior in wind so it must be the vehicle itself and not an alignment problem

I think so ?!

If the sidewalls of the tyres are very high and cheap then there may be felxing when the wind hits the car which you would feel.

 

Larger diameter wheels and lower ratio tyres would reduce this if it was the cause.

Tyre pressures correct?

But as long as me and my cousins car have the same behavior in wind so it must be the vehicle itself and not an alignment problem

I think so ?!

Well yes, there must be a vehicle issue with both cars. That doesn't mean that it's not a problem with suspension geometry (and also doesn't mean that either you or your cousin have caused this by kerbing or bouncing through potholes at speed) since cars have been known to leave the factory with mis-aligned suspension geometry, and the different ride height will require different camber and castor values and possibly different toe settings for best stability. See http://en.wikipedia.org/wiki/Suspension_geometry for further explanation of these terms.

The issue is since day one and our cars are both new bought in Feb 2014

Tyre pressure is as written 33 psi and tested 28 front 33 rear an 33 front 30 rear but those just make the steering heavier only

Also when there is no side winds blowing we can drive till 220 km no problems (tested in certain areas)

Tyres are premium contact 5 for me and Michlans for my cousin

Both 205/55 r16

Off the wall (or at least that's what it sounds like; there is sense behind it) suggestion. I know it can be very hot in Egypt in daytime and very cold at night but try this anyway.

 

Try cracking both front windows open an inch or 2. This works by moving the aerodynamic centre of pressure backwards behind the centre of gravity and reduces the amount that gusts of wind "steer" the car as a result.

But if you are traveling at 120 or 150 km those open windows would cause unbearable noise

But if you are traveling at 120 or 150 km those open windows would cause unbearable noise

You seem to have an argument for every suggestion made for you to try.

 

As has been advised, have your steering geometry checked, the factory set it to within a tolerance as they only have a limited amount of time to work on each car, your local steering specialist will spend more time and will get closer to the best settings for the car.

You seem to have an argument for every suggestion made for you to try.

As has been advised, have your steering geometry checked, the factory set it to within a tolerance as they only have a limited amount of time to work on each car, your local steering specialist will spend more time and will get closer to the best settings for the car.

No man I am not arguing or neglecting your ideas and thanks very much for everyone replied to me , I really appreciate your great help,

We are just discussing problem and possible solutions from everyone point of view ,

Checking steering is taken into consideration and I will check ASAP ,

My main point was asking about the rough road package and what is needed to make it lower and if lowering can help with side wind or not

As per my reply in your other post, I'm not having any issues with our combi 4x4, which has the raised ride height and RRP, which I believe is achieved with taller springs.

 

Ride and steering are very good and I'm also on 205/55 r16 premium contact 5; mind they are rubbish in standing water.

 

Only issue I did have very early on, was down to the Bridgestone winter tyres I'd fitted tram lining but that resolved itself with mileage.

 

 

TP

Off the wall (or at least that's what it sounds like; there is sense behind it) suggestion. I know it can be very hot in Egypt in daytime and very cold at night but try this anyway.

 

Try cracking both front windows open an inch or 2. This works by moving the aerodynamic centre of pressure backwards behind the centre of gravity and reduces the amount that gusts of wind "steer" the car as a result.

 

 

But if you are traveling at 120 or 150 km those open windows would cause unbearable noise

I thought it was already clear that I realised that this was not a permanent solution?

 

My explanation of what was happening if it did stabilise the car (by no means certain) perhaps should have said, but certainly implies, that the issue would then be clearly shown to be a change in the centre of pressure caused by the raised ride height (and hence a design fault. VAG have previous here; the early Audi TTs were aerodynamically unstable at speed)>

I thought it was already clear that I realised that this was not a permanent solution?

My explanation of what was happening if it did stabilise the car (by no means certain) perhaps should have said, but certainly implies, that the issue would then be clearly shown to be a change in the centre of pressure caused by the raised ride height (and hence a design fault. VAG have previous here; the early Audi TTs were aerodynamically unstable at speed)>

I already tried this before driving with windows open and I felt it helped a little but I wasn't sure if it is the windows or just the wind is not much

But in all cases with closed windows it is worse ,

Also I noticed for sure that when the wind is blowing from front of the car you feel as if it is skidding a little and when the wind is pushing from behind the car is dead stable on the road with great planted feeling.

I already tried this before driving with windows open and I felt it helped a little but I wasn't sure if it is the windows or just the wind is not much

But in all cases with closed windows it is worse ,

Also I noticed for sure that when the wind is blowing from front of the car you feel as if it is skidding a little and when the wind is pushing from behind the car is dead stable on the road with great planted feeling.

I don't have a wind tunnel to test in, but I'm now pretty sure that your problem is with one or both of the centre of pressure having moved and the higher ground clearance allowing more air under the car causing more lift at speed. Either way, I'd say that the cure is going to be to fit standard height springs.