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Model specific boards => Golf mk7 => Topic started by: mkviken on 09 April 2018, 08:49

Title: Steering mode
Post by: mkviken on 09 April 2018, 08:49
Searched but can’t find a definitive answer

What does steering mode actually do?

Is it only the weight of does it change the speed of the steering rack too?


I’ve been using race mode but find it feels a bit fake and doesn’t self centre in a natural way.

Feels more natural in comfort or normal but don’t know if it changes the speed of the steering. Might be in my head but feels like the rack is slower in comfort?

Thanks
Title: Re: Steering mode
Post by: fredgroves on 09 April 2018, 09:01
Sport mode gives you a faster turn rate than normal or comfort. It also increase the amount of input effort needed though - presumably to dampen the steering or you'd be all over the shop.

The steering is fully fly by wire anyway - you are only turning an electronic position sensor, not gearing. The "weight" is just electric dampening.
Title: Re: Steering mode
Post by: mkviken on 09 April 2018, 09:37
Ok thanks so it does effect the speed of the rack.

Cheers
Title: Re: Steering mode
Post by: wooders2 on 09 April 2018, 10:07
The steering is fully fly by wire anyway - you are only turning an electronic position sensor, not gearing. The "weight" is just electric dampening.

Is that right, I thought these systems were still assisted, just electronically?  This cutaway looks like it still has a steering column connecting to a rack, but is that actually just connecting to a resistance unit of some sort? 

(https://i.pinimg.com/originals/a8/ed/b6/a8edb6dd74787bf640cc58804210579c.jpg)
Title: Re: Steering mode
Post by: SRGTD on 09 April 2018, 11:15
The steering is fully fly by wire anyway - you are only turning an electronic position sensor, not gearing. The "weight" is just electric dampening.

Is that right, I thought these systems were still assisted, just electronically?  This cutaway looks like it still has a steering column connecting to a rack, but is that actually just connecting to a resistance unit of some sort? 

Those cutaway pictures are of a mk6 Golf.
Title: Re: Steering mode
Post by: fredgroves on 09 April 2018, 11:31
Its not hydraulic like the previous Golfs, its electrically assisted, I'd assume that means your rotational input is translated into mechanical effort by an electric motor, which allows for different steering rates vs input. Yes, the steering column is attached to something, but not directly acting on the rack. The feedback weight is controlled by the electrical motor.
Title: Re: Steering mode
Post by: mkviken on 09 April 2018, 11:56
http://www.volkspage.net/technik/ssp/ssp/SSP_317.pdf

Looking at this it seems the speed of the rack won’t change as the 2 pinion gears work in tandem
Title: Re: Steering mode
Post by: fredgroves on 09 April 2018, 12:08
Sort of how I described :D
Title: Re: Steering mode
Post by: wooders2 on 09 April 2018, 12:13
Its not hydraulic like the previous Golfs, its electrically assisted, I'd assume that means your rotational input is translated into mechanical effort by an electric motor, which allows for different steering rates vs input. Yes, the steering column is attached to something, but not directly acting on the rack. The feedback weight is controlled by the electrical motor.

That's really interesting, thanks for the info  :smiley:
Title: Re: Steering mode
Post by: mkviken on 09 April 2018, 12:18
Sort of how I described :D

It doesn’t say anything about rack speed etc being changed, just the effort required and amount of self centring effect it applies.

Looking through that I don’t think the response or speed of the steering is changed, jus the effort required at the wheel and the amount of self centring is applied.
Title: Re: Steering mode
Post by: fredgroves on 09 April 2018, 12:33
Yes, the amount of input effort vs turning achieved is shown there - ie at slow speeds it turns quicker.

The document doesn't mention the extra set of maps gained by the performance profiles in a performance golf though - those are over and above the speed based profiles - probably a different set of speed profiles.
Title: Re: Steering mode
Post by: wooders2 on 09 April 2018, 12:34
Its not hydraulic like the previous Golfs, its electrically assisted, I'd assume that means your rotational input is translated into mechanical effort by an electric motor, which allows for different steering rates vs input. Yes, the steering column is attached to something, but not directly acting on the rack. The feedback weight is controlled by the electrical motor.

Ah, looking at P16 of that PDF it looks like the steering column is still connected directly to the rack, but there's a second pinion that adds the assistance.  They say on that page:

Quote
The steering pinion transfers the steering force applied by the driver and the drive pinion transfers the assisting force from the electro-mechanical power steering motor via a worm gear.

I'm quite relieved by that.. not sure I'm ready to trust a full drive-by-wire quite yet!
Title: Re: Steering mode
Post by: mkviken on 09 April 2018, 13:03
If the column is connected to the same driven part as the the motor then I can’t see the ratio of the rack changing

It does feel that more lock was required in comfort though at times
Title: Re: Steering mode
Post by: cossiegaz82 on 09 April 2018, 14:35
There's no way the steering can be drive by wire for safety reasons, if the car was to suffer total power failure for example, you'd be up s**t creek without a paddle. The motor is built into the rack which the steering column is attached to just like a conventional rack and pinion system.
Title: Re: Steering mode
Post by: maxie on 09 April 2018, 14:38
There's no way the steering can be drive by wire for safety reasons, if the car was to suffer total power failure for example, you'd be up s**t creek without a paddle. The motor is built into the rack which the steering column is attached to just like a conventional rack and pinion system.

well i cant move my wheel when the engines off while stopped, not sure what would happen whilest moving though. :) must admit it has had me thinking what would happen before now :)
Title: Re: Steering mode
Post by: wooders2 on 09 April 2018, 16:05
well i cant move my wheel when the engines off while stopped, not sure what would happen whilest moving though. :) must admit it has had me thinking what would happen before now :)

Steering lock?  I think that's automatic (i.e. doesn't require a jiggle of the steering wheel to engage) judging by the icon on the dash?
Title: Re: Steering mode
Post by: maxie on 09 April 2018, 16:35
well i cant move my wheel when the engines off while stopped, not sure what would happen whilest moving though. :) must admit it has had me thinking what would happen before now :)

Steering lock?  I think that's automatic (i.e. doesn't require a jiggle of the steering wheel to engage) judging by the icon on the dash?

i mean when the stop start system kicks in (sorry) sometime it kicks in while still moving and the  steering wheel is still solid :)
Title: Re: Steering mode
Post by: fredgroves on 09 April 2018, 16:53
Yes without any power assistance, with big fat tyres,  with gearing not designed to be used without power assistance and stationary... its going to be hard work.

I drove a car without power steering a while back and had forgotten just how hard turning at slow speeds is!
Title: Re: Steering mode
Post by: cossiegaz82 on 09 April 2018, 18:51
It is pretty stiff but when on the move the resistance decreases so not as bad. Still stiff though.

When towing VW's with electric power steering, with the ignition on the power steering comes on.
Title: Re: Steering mode
Post by: golfdave on 09 April 2018, 19:35
Besides the self study book 317 which was linked to you need to read number 521 "The Golf GTI/GTD 2013".

This explains why the GTI/GTD/R steering rack is different to the one described in the book 317...

Basically the steering rack has two sets of grooved/teeth strips on the rack..one for each pinion...the steering pinon section on the "progressive" rack (GTI/GTD/R)  has standard straight teeth on the straight ahead section in the middle, but then either side it has angled teeth....which means the rack covers a greater distance for the same input...

So standard for 60deg either side of dead ahead....then basically you input turn 360deg either side from dead ahead & get full lock ..where as on standard rack you have to input 540deg either side to get full lock...

You also get a more powerful electric motor ...& on all MK7 it is a synchronous...not asynchronous...
Title: Re: Steering mode
Post by: wooders2 on 09 April 2018, 19:59
The lock's so bad on mine compared to my transporter I was wondering if they'd got that "two turns lock to lock" by simply reducing the length of the rack..  :grin: :evil:
Title: Re: Steering mode
Post by: mkviken on 10 April 2018, 10:17
Besides the self study book 317 which was linked to you need to read number 521 "The Golf GTI/GTD 2013".

This explains why the GTI/GTD/R steering rack is different to the one described in the book 317...

Basically the steering rack has two sets of grooved/teeth strips on the rack..one for each pinion...the steering pinon section on the "progressive" rack (GTI/GTD/R)  has standard straight teeth on the straight ahead section in the middle, but then either side it has angled teeth....which means the rack covers a greater distance for the same input...

So standard for 60deg either side of dead ahead....then basically you input turn 360deg either side from dead ahead & get full lock ..where as on standard rack you have to input 540deg either side to get full lock...

You also get a more powerful electric motor ...& on all MK7 it is a synchronous...not asynchronous...

That makes sense. I couldn’t see how the ratio of the rack could be changed by the mode setting. There has been times in comfort though that I’ve felt I’ve needed more lock🤔

I’m going to run it in comfort and normal for a while and compare it.

I’m sure the steering feels more natural in comfort compared to race.
Title: Re: Steering mode
Post by: scanesare on 10 April 2018, 13:38
Does the CSS have a comfort steering mode for some reason?  :huh:

CS only has two options: Normal and Sport (talking about steering options, not Drive profiles) so in Comfort drive profile (and basically in every profile minus Sport/Race) i guess it's using "Normal" steering?
Title: Re: Steering mode
Post by: mkviken on 10 April 2018, 14:45
Yeah the CSS has pre defined modes comfort sport/normal and race and individual

In individual you can change from comfort normal and race for steering, suspension, engine sound, diff and headlights and engine drive has either race or normal
Title: Re: Steering mode
Post by: scanesare on 10 April 2018, 19:55
Ok that's weird. On the CS, in Individual mode, you can only set steering either to Normal or Sport. There are comfort options for Suspension and Drive but not for steering. Wonder why comfort steering would be an option on the CSS but not on the CS considering they are supposed to be the same system from what we know. Purely academic though as I don't think comfort steering would be my choice, Normal does the job well, prefer it to Sport as that's too heavy.