Car feels unsettled and wanting to rotate on slippery roads. Quatt-no?

[Christanza]

Since the roads have begun to degrade this winter and become more snowy, icy and generally slippery, I’ve noticed something odd with how my car has been handling.

It feels as though the car wants to rotate counter-clockwise and I am continuously having to make minor steering corrections to counter-act the car's behaviour of twisting around and being all "hey what's that over to the left!?"

So far this has only been a minor nuisance and hadn’t really registered on the “I should get this looked into” scale, but after experiencing 1.5 hours of butt-puckering terror on an icy highway earlier today, I thought I’d see if I could get to the bottom of what was causing my bottom to pucker.

Before I go into what I think the problem may be, I thought I’d share some details for context:

- The car is lowered on KW coilovers
- Winter tires are Bridgestone Blizzak LM 25V’s and are slightly wider than stock spec: 265/35/19 (stockers are 255’s)
- Tread depth on winters is good (9/32 all around) and no uneven wear
- The speed at which the puckering effect becomes most apparent is above 70km/h (45mph)
- It doesn’t do this when the roads are dry or wet or slushy or even a bit snowy – it happens on compacted snow, ice, or generally speaking, more slippery conditions.
- I never experienced this with my previous RS4 (completely stock and on 255/35/19 Pirelli winters) and did lots of winter highway driving in even worse conditions than today.

[edit: added some further detail about the tire pressure and the set up of my previous RS4]

Here are some pictures. Because pictures.







My initial thought was that my alignment was out of whack, but after getting the alignment checked this afternoon and being told it’s all within normal ranges, I’m left a bit puzzled. Here are the results of the alignment check btw:

FRONT

Left Caster: 4.03°
Right Caster: 3.82°

Left Toe: 0.08°
Right Toe: 0.17°

Left Camber: -1.72°
Right Camber: -1.61°

REAR

Left Toe: 0.17°
Right Toe: 0.29°

Left Camber: -1.77°
Right Camber: -1.44°

Thrust Angle: 0.07°

Some questions / thoughts as to what may be the culprit:

1. Perhaps these alignment values ARE out of whack, and the technician who told me they weren’t out of whack, was out of whack himself. Could 0.29° of toe in the right rear be enough to cause the car to want to swing its ass out?

2. Could it be my tires? The technician who checked the alignment suggested that they may be the cause but didn’t offer any additional details to support his reasoning.

3. Could it be Quattro-related?

4. Could it be suspension-related?

5. Could it be me-related?

Any and all insights, suggestions, thoughts, etc. are most appreciated!

I just want to get this resolved so my wife and I can go skiing and not die on the highway.

Thanks, folks!

[iduff]

Dragging left rear brake? Easy enough to tell, is it warmer than the right rear brake after an extended drive?

You should be able to tell by putting your hand on the rear wheel center and feeling it for temps.


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[your daddy]

i would get the alignment dialed in better. centerline is off.

[LINDW4LL]

Hmm, quite odd.

I was already going to suggest that your alignment may be off before I got to that portion of your post. I'm no alignment expert but I'd be surprised if it's off enough to cause any issues as nothing really stands out.

Not sure what else it could be.

[forbiddenbeat]

When checking alignment, did they also check for play in your control arms or other suspension components?

Does the pull get worse when accelerating/decelerating?

[jakeoboy67]

are you sure it doesn't have anything to do with road conditions ? uneven traction for the left/right wheels, something like icy "lanes" on the highway ?

try to find a spot where the traction is equal left/right (e.g "virgin" parking lot snow) , and try to replicate this "rotation" by simply accelerating

[lucidmatt]

Occum's razor: how high are the crowns on your roads? rear biased AWD+ wide tires (even snow tires)+off camber road = counterclockwise rotation

[Blackstallion]

I got nothing to add other than what has been said.

Also I was wondering who picked up Ginch's old car--congrats!

[skhan91]

having the same issue, same city as well haha

but i do have 255/40/19 blizzaks on mine and the upper CAs need to be redone as well, so im guessing that could be the cause of this issue on my car?

[Christanza]

Dragging left rear brake? Easy enough to tell, is it warmer than the right rear brake after an extended drive?

You should be able to tell by putting your hand on the rear wheel center and feeling it for temps.

I didn’t think of that but I’ll go for a drive today and check that out!

i would get the alignment dialed in better. centerline is off.

Yeah, I’m going to go back and get them to re-align so the toe is as close to 0 as possible.

Hmm, quite odd.

I was already going to suggest that your alignment may be off before I got to that portion of your post. I'm no alignment expert but I'd be surprised if it's off enough to cause any issues as nothing really stands out.

Not sure what else it could be.

Other input I’ve received is that it may be a combination of the wide tires, lowered suspension and the rear toe being out that is causing this to happen.

The current mathematical formula that is beginning to emerge seems to be something along the lines of:

RS4 + ((toe x steamrollers) + lowered + icy) = dirty underwear

When checking alignment, did they also check for play in your control arms or other suspension components?

Does the pull get worse when accelerating/decelerating?

I don’t think they checked anything else, no. I just took it to a Kal Tire because they were the only ones who could sneak me in and get it on their alignment machine in between the appointments they had, so they didn’t spend much time with it. 

I’ll get them to check that when I go back to have them do the re-alignment today.

Oddly enough, the handling was the worst when I was at a steady throttle or lifting slightly (but not so much as to be inducing a sudden weight transfer or anything). Strange.

are you sure it doesn't have anything to do with road conditions ? uneven traction for the left/right wheels, something like icy "lanes" on the highway ?

try to find a spot where the traction is equal left/right (e.g "virgin" parking lot snow) , and try to replicate this "rotation" by simply accelerating

I think that the road conditions definitely played a part yes (see mathematical formula above) - lots of cars were skidding off into the ditch, and the roads were super slippery! But it seemed to be pretty uniform across the entire road and irregardless of what lane I was in.

Occum's razor: how high are the crowns on your roads? rear biased AWD+ wide tires (even snow tires)+off camber road = counterclockwise rotation

I never thought of this, but there were areas where the crown was high! I need to adjust my formula.

RS4 + (((toe x steamrollers) + lowered + icy) x high crowns) = dirty underwear

I got nothing to add other than what has been said.

Also I was wondering who picked up Ginch's old car--congrats!

Thanks! As soon as he listed his car for sale, I called him to ask if I could buy some parts from him, which soon made me realize that if I could just sell my car it would be easier just to buy his. So I listed my RS4 and sold it just in the nick of time to scoop Ginch’s.

having the same issue, same city as well haha

but i do have 255/40/19 blizzaks on mine and the upper CAs need to be redone as well, so im guessing that could be the cause of this issue on my car?

Saad - I’ll let you know how things progress after I get the alignment done. I wonder if your rear toe may be out as well. I’m also going to probably take Danno up on the offer to drive his RS4 that is on 225/45/18’s to see what difference that makes.



THANKS FOR ALL THE INPUT AND HELP, FELLAS!

[skhan91]

addressing everyone's input like a baws!

[ECS Tuning-Audi]

Rear specs need to be dialed in more. Take it back to the alignment shop.

Jason

[FWP!]

.29 in the right rear is a lot of toe. My left rear is at .25 and I really want it to be .05 ideally on both sides, but my eccentric bolt on that left rear is maxed out somehow. With that much toe on yours I'm not really surprised to hear you're experiencing some poor road manners in the snow. My car doesn't feel totally "perfect" at speed, especially on the wet highway, but I'm not sure how to fix it and I'm just dealing with it for now. They tell me I should replace the lower control arm because it's probably bent, but I didn't have this issue until one day randomly I had it aligned (after loosening and re-tightening the front subframe), and I never hit anything. Plus, the lower control arm is cast aluminum, it's going to shatter, not bend.

[ECS Tuning-Audi]

^^ When the rear subframe was loosened it could have shifted. Not sure how much of an effect it would have but it is definitely plausible because the B8 guys have issues with tires sticking out further on one side compared to the other in the rear. Some have found their vehicle came from the factory with a misaligned sub frame and the suspension was just dialed in to compensate it. But when they go the realign after lowering they get all sorts of wild suspension specs. When the alignment shop tries to get it back to "straight" usually one side ends up sticking out further than the other from what I understand.

Jason

[FWP!]

^^ When the rear subframe was loosened it could have shifted. Not sure how much of an effect it would have but it is definitely plausible because the B8 guys have issues with tires sticking out further on one side compared to the other in the rear. Some have found their vehicle came from the factory with a misaligned sub frame and the suspension was just dialed in to compensate it. But when they go the realign after lowering they get all sorts of wild suspension specs. When the alignment shop tries to get it back to "straight" usually one side ends up sticking out further than the other from what I understand.

Jason

It was the front subframe that was loosened, not the rear on mine. For the rear, the only time I've ever loosened it was to install the H&R springs two years ago. But the shop was able to align it to within spec no problem afterwords. I then had it re-aligned about a year later after I installed front upper adjustable control arms and they again were able to align it no problem. Then a few months later I installed B5 front lower perches and had it aligned once again, and that's when Audi said the left rear must be bent because they couldn't get it near spec. But I've never hit anything, not even any pot holes. I do remember reading somewhere on here where someone had the same issue after lowering their RS4, the rear was toed pretty far out like mine. I am running very little camber in the rear according to my last post-alignment spec sheet (-.6 degrees on the left, -.8 on the right) and I'm wondering if that's what's causing the toe-out, maybe dialing in more camber will increase toe-in to get me in spec?

[silverRS4]

Your total rear toe is 0.46 (.29+.17). Get that to less than 0.10 and your problem will be solved.

[FWP!]

Your total rear toe is 0.46 (.29+.17). Get that to less than 0.10 and your problem will be solved.

I'm curious if what he posted is for toe out or toe in. Usually a positive number in the back means toe out, no?

[FWP!]

Hmm.. this thread has me thinking. Does a positive number for rear toe actually mean toe IN? Here's my most recent print-out:




And here is the left rear eccentric bolt:




Does this mean the left rear has a lot of toe-IN and that bolt is showing that it is adjusted fully to one direction giving as much toe-OUT as possible? Or is it the other way around?




Right bolt for comparison -

[Flying Tomatoes]

Alignment is definitely wacky.

Something I didn't hear anyone else mention is that those are really wide snow tires. Most people try and go as narrow as possible for winter/snow tires. Might want to consider something smaller next time as it should also help reduce some float. I think the better quality Pirelli winters combined with their more narrow contact patch would make some noticable difference in the winter handling but I don't really think thats the root of your issue here.

[musanoadsaba]

Maybe wait and take it to Riegel when they can fit you in. Were you just noticing this on the highway?

[Marky G]

I have nothing to add in terms of suggestions for your trouble shooting, but just wanted to chime in and say that you have kept Derek's old car still looking clean and glorious as always, especially during a Calgary Winter season! Even though it wants to pull you into the ditch, you will look good doing it and I think that is what really matters here.

[ginch]

I have nothing to add in terms of suggestions for your trouble shooting, but just wanted to chime in and say that you have kept Derek's old car still looking clean and glorious as always, especially during a Calgary Winter season! Even though it wants to pull you into the ditch, you will look good doing it and I think that is what really matters here.

Yup! Perfect new custodian for the car!!!!! See you in a month Mark!

[Christanza]

Sorry I didn't post an update earlier, but got caught up in holiday stuff last week.

I took the car in to get the alignment re-done and centre out the toe in both the front and rear, and so far it seems much better. Although now that the weather warmed up and the streets aren't as slippery it's a bit difficult to tell until the next time the roads get icy. In the meantime, the amount that the front and rear toe were out in my car seems to have been the primary culprit (which was exacerbated by wide winter tires) but I'll keep this thread updated if the issue returns and I need to continue the trouble-shooting.

Thanks to you all for your input!!