Handling question - issues with an RS6 having come from a B8 RS4...

[MikeBirt]

Hi All,
Recently moved from a 2014 B8 RS4 with dynamic package and 20" rims to a 2016 RS6 with dynamic package (incl drc and Sports diff) with 21" rims.

Now I've had the RS6 for a few weeks, on all my local roads and have played with the settings and traction control settings I have a questions that longer term RS6 owners may be able to answer, to see if what I have found is a characteristic of the car, or wether there is something up with mine..

The RS4 B8 I had I liked a lot - owned it for 2 years an knew it's handling inside out.
You could get on the power crazy early through a corner - as soon as the nose was in, down goes some power, all of it if you wanted, the back would step out a fraction but the diffs would catch it and it would dig its way out of the corner, in a manner that seemed to defy the laws of physics. Glorious!

The RS6, the nose is perhaps a bit less willing, but you can get it thrown in to a reasonable degree, but then if you dare to go near any power nothing seems to happen, other than the traction control system lighting up like a Christmas tree. Wheels brake, engine cuts back, the car twitches between weighting random wheers and the thing makes out like the world is coming to an end, before the corners G starts to wane, the traction lights start to diminish, and it decides that the power can come back. I tried turning stability control off (like the RS4 it makes no difference) and with it completely off, again, the traction system is unaffected - still impossible to 'drive'.

To the RS6 the word oversteer is an impossibility; not only would it not let oversteer happen, it would not let the power go down to ever get near to letting it happen.

The other two things I noticed is that under sharp off camber acceleration - say pulling away from a cambered junction with pace it momentarily spins up the inside rear wheel. Also - in a car park with the diff setting in dynamic you could feel the inside rear wheel actually slightly spinning the inside rear wheel at full lock - classic characteristic of the LSD. The RS6 never does this....

What is your experience?

I know the 6 is a lot more powerful, if bit heavier, but my experience is that my RS6 is a van, and a conservative one at that, yet the 4 was possibly the grippiest and most tactile / composed cars I have ever owned.

The RS6 is still in warranty - I'm thinking of booking it in. One of the three diffs must be wrong.

[MikeFish]

The 6 won't compare to the 4 in terms of agility. But it should be comparable in terms of grip. In 2 and a half years I think I've only seen the traction light come on once or twice. Is your gearbox in S mode when pulling away? The throttle mapping is dampened in D mode so for me seems too lagging pulling away. I always pull the gear lever back on approach to junctions to shift into S mode.

What tyres do you have and how much grip is left on them? Sounds like bad tyres to me.

[MikeBirt]

In 2 and a half years I think I've only seen the traction light come on once or twice.

really? mine s on like a Christmas tree as soon as I start to power out of corners.

Is your gearbox in S mode when pulling away? The throttle mapping is dampened in D mode so for me seems too lagging pulling away. I always pull the gear lever back on approach to junctions to shift into S mode.

Possibly not, but when I do try and push on I am pretty much always in Dynamic or have dynamic on all gearbox diff setting in the individual config. To be honest I have tried all settings.

What tyres do you have and how much grip is left on them? Sounds like bad tyres to me.

They are good tyres, p zero I think - all 6mm. Also - if they were bad tyres it would effect the lateral grip, not the balance or ability of the car to position itself and lay down power out of a corner. I cant help but feel that something is awry..

[MikeFish]

P zeros are pretty rubbish to be fair. However, I wouldn't expect them to be as bad as you say with 6mm of tread and in the dry and assuming you are in the UK it is relatively warm. In the winter I'd expect this with those tyres.
And poor tyres will definitely affect the ability to lay down the power whether on the straight or coming out of a corner. The quattro is good but it can't completely overcome the failing of a poor tyre.
Have you checked the tyres pressures?
And had the geometry checked?

[MikeBirt]

pressures checked, geometry done 2 weeks ago...
I have a local contact who went 4 to 6, same as I.
He needs to drive my car and we need to have a chat I guess.
I hope there is something wrong with it, as to be honest I find it disappointing if this is normal.

[MikeFish]

It does sound like something is off, it's certainly not my experience. I came from a B7 RS4 and didn't experience the same.

Edit; obviously, with the B7 I could floor it almost any time, wet or dry and it would grip and go. Not the same with the 6 as it has a lot more torque and will kick out or spin a lot more easily than the normally aspirated lower torque RS4.

[innercry666]

I came from a B8 RS4 to the RS6 and I find the RS6 handles much better than the 4. It has a lot less tendency to want to understeer. The steering feels sharper and a lot more pointy then the RS4 as well. I had the RS4 geometry set up by Centre of Gravity which improved it significantly in the handling stakes, but it still couldn't hold a candle to the 6. With the 6 there is a lot more confidence in how the car handles and how you can place it on the road and how it responds. It can be pushed a lot harder.

From my experience of both cars it definitely sounds like something is off with yours.

[Macdaddy]

I came from the B8 RS4 to the C7 RS6.

Very similar in terms of agility perhaps the RS4 marginally edges it with it being lighter.

In overall terms the RS6 is in another league power wise,
You should be grinning ear to ear wishing you'd changed sooner.

Definitely sounds like yours has an issue as I've pushed the RS4/6 and found the traction fairly unobtrusive on public roads.

[MikeBirt]

Thanks very much for that - yup - mine sounds well out.
No question it is quicker in a straight line, but exiting a corner I could not hope to keep up, would be 4 car lengths back on my old RS4, and I'm rolling my eyes constantly.
I'll get it booked in.

[Ian_C]

And had the geometry checked?

Mike - post a link to your geometry thread.

General consensus is to remove the factory rear axle toe-in, which reduces understeer when cornering, and removes the 'rear steer' affect when you floor it in a straight line and the cambers/catseyes/white lines cause one wheel to lose grip slightly and the other wheel (with toe-in) steers the car as a result. Even going from 0.2 degrees toe-in per side back to zero makes a big difference. Mikes thread has much more info.

[MikeBirt]

And had the geometry checked?

Mike - post a link to your geometry thread.

General consensus is to remove the factory rear axle toe-in, which reduces understeer when cornering, and removes the 'rear steer' affect when you floor it in a straight line and the cambers/catseyes/white lines cause one wheel to lose grip slightly and the other wheel (with toe-in) steers the car as a result. Even going from 0.2 degrees toe-in per side back to zero makes a big difference. Mikes thread has much more info.

That is very interesting. I spent years on supras getting the geo right - it was absolutely critical. I assumed that with the electronic power distribution systems in these things it didn't make much difference, as my old supras were 100% mechanical only.
The geo files will be the audi stock geo - as it was done by them before I bought it.
One of the reasons I went to the RS4 was the fact I never had to mess around with it at all - I was sick of spannering around.

I'll book it into Audi and see what they say first, my instinct is that it's inability to put any decent power down on exit is a diff related issue. I just hope the mechanic understands these things properly and doesn't just plug a machine in that says 'no fault'.

[MikeFish]

Ian, was this the thread you were talking about?

viewtopic.php?f=76&t=120887

[innercry666]

And had the geometry checked?

Mike - post a link to your geometry thread.

General consensus is to remove the factory rear axle toe-in, which reduces understeer when cornering, and removes the 'rear steer' affect when you floor it in a straight line and the cambers/catseyes/white lines cause one wheel to lose grip slightly and the other wheel (with toe-in) steers the car as a result. Even going from 0.2 degrees toe-in per side back to zero makes a big difference. Mikes thread has much more info.

That is very interesting. I spent years on supras getting the geo right - it was absolutely critical. I assumed that with the electronic power distribution systems in these things it didn't make much difference, as my old supras were 100% mechanical only.
The geo files will be the audi stock geo - as it was done by them before I bought it.
One of the reasons I went to the RS4 was the fact I never had to mess around with it at all - I was sick of spannering around.

I'll book it into Audi and see what they say first, my instinct is that it's inability to put any decent power down on exit is a diff related issue. I just hope the mechanic understands these things properly and doesn't just plug a machine in that says 'no fault'.

Test drive it with the master tech. As long as you can demonstrate the issue and as long as they understand the issue then they should then investigate. Unfortunately Audi dealerships are notorious for not having the skill set or experience necessary to diagnose issues that aren't recorded in the fault log.

On that note having Audi do the geometry can be very hit and miss as well as not all techs are created equal. They aren't usually allowed enough time to set the car up correctly before carrying out the alignment so invariably get it wrong, even if the computer tells them everything is all in the green.

Sometimes the best way to point out the issue is in comparison with another car, however I suspect you would need to take someone with you...

[Markp]

Never noticed a traction control light in anything but snow in 30,000 miles, and handled really well for a 2 tonne family estate. My bet would be poor geo - and the fact that the dealer did it recently makes it even more likely
The 6 is very sensitive to full throttle over cambers (eg when overtaking) but otherwise docile handling wise.

[Covkiller]

If you have the funds £500, take it to Centregravity and Chris will sort it out, no question.