M3 corner/high speed stability issues

[Strongbad]

Hi everyone.

Picked up a '17 M3 ZCP a few months ago and I have been noticing that when I am cornering (ie. freeway on/off ramp) the car will sometimes get unsettled and twitch in the middle of the corner (feels like a split second of understeer in the middle of the corner before the car corrects itself). This is happening at speeds of 35-45 mph and happens when I am both on and off the throttle so its not something that has to do with coming into the corner with too much speed. Needless to say this is very unnerving and makes me apprehensive about driving the car the way it is meant to be driven. I am sending the car in to have the alignment checked on Thursday to see if that could be the issue.

I used to have a 2015 M4 and never noticed this behavior so I am wondering if it is a product of having the competition pack or if something is wrong with my car. ( I am leaning toward the latter.)

Another, possibly related, issue I am having is that this car feels much less stable at high speeds (above 85MPH) than the M4 did. I have never driven another F80 M3 so I am not sure if the M3 is inherently less stable at high speeds than the M4 or if it could be another symptom of the same issue that I am having while cornering.

My car also came from the dealer with the front splitters/lip installed but does not have the M performance spoiler installed so I am wondering if that is messing with the stability of the car at higher speeds because I have read that BMW recommends installing both the splitters and spoiler together.

Sorry for rambling but trying to see if anyone had similar issues and how they were resolved.... Hoping the alignment fixes it but we will see.

[neilum]

What tires on it? and what condition?

My old S2000 used to do that mid-corner. If you lifted the entire rear of the car would become suddenly unsrpung and felt very unnerving. However, I have not noticed this behavior in the F80, there is no mid-corner weight transfer, that I can feel at least.

Car is actually very planted.

Sounds like something is off, I was doing 140 at the track and the car was solid.

Are all of the bolts connected to the front or rear sway maybe? Was the car ever modified?

[Strongbad]

It seems like everything is connected but I'll have the dealer give it a once over on Thursday.

Tires are the original PSS's with 3k miles on them and the only mods on the car are a JB4 and the dealer installed front splitters/lip. I am taking the car from RI to Buffalo on Friday so I'm really hoping to get it straightened out by then.

[Projectile]

I went from 2015 M4 to 2017 M3 with ZCP and I have noticed the opposite: the car feels significantly more planted in round-abouts and on/off ramps. It hunkers down and bites while the M4 felt more wobbly (ie. more body roll and nose dive). I haven't noticed any twitch mid corner at the slow speeds you're describing. As you approach the grip limit of the tires, one might feel a slight slide, especially after a small road imperfection, but the car should settle and bite again in a confidence inspiring way, but that's at higher speeds than you're describing. At least that's my experience...

Worth getting the car checked out, it seems. I can't comment on the splitter/spolier issue, but it seems fairly easy to remove the splitter and re-install if you want to do that test.

[mm767cap]

I have the EXACT same experience, same car, same mileage. I noticed it was worse with the PSS than with the PS4's. However, when I put the M Performance Suspension on, it actually came back a little WORSE. I figured it was just a characteristic of the car, but it sounds like not every car has it happening.

Please update what you hear from the dealer

[Colinv6]

My comp m3 with ACS springs (dealer fitted before collection) doesn't feel quite right on high speed bends, it can feel very unnerving, not twitchy as in the back end coming round,
But a feeling of for a second or 2 you don't really have control over the car very much.

If also agree that I feel like this car is less planted than my previous 2015 M3, same springs but fitted and set up by AC Schnitzer UK,

I'm hoping this is just an alignment error, car is planted and stable at high speed etc, it's just on corners, and if you back off mid corner it feels like the car just understeers, whereas my old one just tucked in further at the front.

[suprajjang]

Originally Posted by Strongbad

Hi everyone.

Picked up a '17 M3 ZCP a few months ago and I have been noticing that when I am cornering (ie. freeway on/off ramp) the car will sometimes get unsettled and twitch in the middle of the corner (feels like a split second of understeer in the middle of the corner before the car corrects itself). This is happening at speeds of 35-45 mph and happens when I am both on and off the throttle so its not something that has to do with coming into the corner with too much speed. Needless to say this is very unnerving and makes me apprehensive about driving the car the way it is meant to be driven. I am sending the car in to have the alignment checked on Thursday to see if that could be the issue.

I used to have a 2015 M4 and never noticed this behavior so I am wondering if it is a product of having the competition pack or if something is wrong with my car. ( I am leaning toward the latter.)

Another, possibly related, issue I am having is that this car feels much less stable at high speeds (above 85MPH) than the M4 did. I have never driven another F80 M3 so I am not sure if the M3 is inherently less stable at high speeds than the M4 or if it could be another symptom of the same issue that I am having while cornering.

My car also came from the dealer with the front splitters/lip installed but does not have the M performance spoiler installed so I am wondering if that is messing with the stability of the car at higher speeds because I have read that BMW recommends installing both the splitters and spoiler together.

Sorry for rambling but trying to see if anyone had similar issues and how they were resolved.... Hoping the alignment fixes it but we will see.

I am seeing similar characteristics as you with the only difference being that my car does feels stable at high speeds. I also have a 17 ZCP M3 and there has been multiple times around corners where the car felt very unsettled and twitchy without being anywhere near the limits of the car. I have the M spoiler but not the splitters. I was going to bring it up on my next service but interested in what you find when you visit the dealership!

[MN2///M]

Got to be the tire pressure....

Honestly, my 2016 ZCP with DCT is rock solid, all the way to top speed. I routinely hit >100MPH on all kinds of roads. The car is so planted that my only concern is that I am going to be over confident with the car when I shouldn't maybe push so hard.

[Strongbad]

Funny enough tire pressures were the first thing I checked hoping that it was something stupid like tthey this morning they were 32psi @ 60 degrees all around. They get up to about 37psi @90-100 degrees once hot. I believe those are right at factory spec.

Seems like there are a couple more cars having the same issue as well. I'm hoping they find something at the dealer on Thursday and I'll report back if I get anywhere.

[afadeev]

Originally Posted by Strongbad

Picked up a '17 M3 ZCP a few months ago and I have been noticing that when I am cornering (ie. freeway on/off ramp) the car will sometimes get unsettled and twitch in the middle of the corner (feels like a split second of understeer in the middle of the corner before the car corrects itself). This is happening at speeds of 35-45 mph and happens when I am both on and off the throttle so its not something that has to do with coming into the corner with too much speed.

Originally Posted by mm767cap

I have the EXACT same experience, same car, same mileage. I noticed it was worse with the PSS than with the PS4's. However, when I put the M Performance Suspension on, it actually came back a little WORSE. I figured it was just a characteristic of the car, but it sounds like not every car has it happening.

This is EXACTLY what I experience when I'm tracking the car with TC ON (either DSC of MDM) - TC starts interfering, inducing understeer when the car was otherwise perfectly balanced. It's more obvious in high speed turns (70+ mph), but is definitely present in lower speed corners as well. The DSC light only flashes when the TC is kicking-in aggressively (cutting off power), but TC seams to interference on other unannounced occasions as well.

For me, on track, the solution is to turn TC OFF entirely, and the car returns to its perfectly well balanced, predictable self.

On the street, I drive with DSC ON, and just back off the corner entry speeds.

YMMV,
a

[nicknaz]

Hi OP, I'd check the alignment and maybe ask to get the rear diff checked

[knightarmor]

No high speed problems here. Even rain feels good. I'm on the Contis.
I do have one issue where taking hard near 90 degree turns, while accelerating out it feels like the rear end is hopping. Almost feels like I have a spool installed back there!!!

[SMC23]

Originally Posted by Strongbad

Hi everyone.

Picked up a '17 M3 ZCP a few months ago and I have been noticing that when I am cornering (ie. freeway on/off ramp) the car will sometimes get unsettled and twitch in the middle of the corner (feels like a split second of understeer in the middle of the corner before the car corrects itself). This is happening at speeds of 35-45 mph and happens when I am both on and off the throttle so its not something that has to do with coming into the corner with too much speed. Needless to say this is very unnerving and makes me apprehensive about driving the car the way it is meant to be driven. I am sending the car in to have the alignment checked on Thursday to see if that could be the issue.

I used to have a 2015 M4 and never noticed this behavior so I am wondering if it is a product of having the competition pack or if something is wrong with my car. ( I am leaning toward the latter.)

Another, possibly related, issue I am having is that this car feels much less stable at high speeds (above 85MPH) than the M4 did. I have never driven another F80 M3 so I am not sure if the M3 is inherently less stable at high speeds than the M4 or if it could be another symptom of the same issue that I am having while cornering.

My car also came from the dealer with the front splitters/lip installed but does not have the M performance spoiler installed so I am wondering if that is messing with the stability of the car at higher speeds because I have read that BMW recommends installing both the splitters and spoiler together.

Sorry for rambling but trying to see if anyone had similar issues and how they were resolved.... Hoping the alignment fixes it but we will see.

Thought it was just a one off when it happened to my 17' m3 as well, but this happens to me every now and then when going about 40-50k/h on an on-ramp.

Could this be the diff? Was yours replaced?

[NewM3driver]

I've never felt that with the ZCP. Especially at 35 or 40 mph. My car is very solid.

[mm767cap]

Originally Posted by afadeev

This is EXACTLY what I experience when I'm tracking the car with TC ON (either DSC of MDM) - TC starts interfering, inducing understeer when the car was otherwise perfectly balanced. It's more obvious in high speed turns (70+ mph), but is definitely present in lower speed corners as well. The DSC light only flashes when the TC is kicking-in aggressively (cutting off power), but TC seams to interference on other unannounced occasions as well.

For me, on track, the solution is to turn TC OFF entirely, and the car returns to its perfectly well balanced, predictable self.

On the street, I drive with DSC ON, and just back off the corner entry speeds.

YMMV,
a

Interesting. I'll try the corners that this happens to me on with the TC off and see what occurs. The best way I can describe the sensation to those that haven't experienced it: it feels like when you lift slightly (around 40mph in a long sweeping corner) that the wheel rolled off the front end of the tires for a second. I can confirm it's the same with ZCP suspension AND M Performance suspension.
Not an alignment issue as my car just had one. Not a tire pressure issue unless folks are running pressures other than the manufacturer recommended ones because that's where mine are sitting.

[smh_amg_m4gts]

I'll come test drive it for you when I'm out in the East Coast! My 15' F80 was stable at 125+ MPH and all speeds below that.

The only thing I can think of that might contribute to the issue is your DSC settings. Are you driving with all your nannies off?

[Alpine300zhp]

Originally Posted by Strongbad

Funny enough tire pressures were the first thing I checked hoping that it was something stupid like tthey this morning they were 32psi @ 60 degrees all around. They get up to about 37psi @90-100 degrees once hot. I believe those are right at factory spec.

Seems like there are a couple more cars having the same issue as well. I'm hoping they find something at the dealer on Thursday and I'll report back if I get anywhere.

Do me a favor. Bump the fronts to 34 psi (cold) and the rears to 35 psi (cold). See if the instability goes away.

[Strongbad]

Originally Posted by mm767cap

Interesting. I'll try the corners that this happens to me on with the TC off and see what occurs. The best way I can describe the sensation to those that haven't experienced it: it feels like when you lift slightly (around 40mph in a long sweeping corner) that the wheel rolled off the front end of the tires for a second. I can confirm it's the same with ZCP suspension AND M Performance suspension.
Not an alignment issue as my car just had one. Not a tire pressure issue unless folks are running pressures other than the manufacturer recommended ones because that's where mine are sitting.

This is probably the best description that I have heard for what this feels like.

While looking to see if there were any TSB's the F8X's I did find that there were 2 TSB's that seem like they could potentially cause the same issue. One was for the rear subframe bolts and the other was for the differential. These TSB's were only for F8Xs with build dates up to 7/4/16 and mine was built 10/16 but I am wondering if there could be a lingering issue with some cars built after the July 4th date.

[Strongbad]

Originally Posted by smh_amg_m4gts

I'll come test drive it for you when I'm out in the East Coast! My 15' F80 was stable at 125+ MPH and all speeds below that.

The only thing I can think of that might contribute to the issue is your DSC settings. Are you driving with all your nannies off?

I usually drive in MDM but I don't think I've ever seen the light flash while cornering at those relatively mundane speeds. I will try driving with DSC completely off and see if that makes a difference.

Let me know if you come out, we can go for a ride.

[Strongbad]

Originally Posted by Alpine300zhp

Do me a favor. Bump the fronts to 34 psi (cold) and the rears to 35 psi (cold). See if the instability goes away.

Ill give this a try today and see if it makes any difference.

[momo3605]

I have the exact same issue. But mine became noticeable after installing bilstein coilovers and fall line rear toe links. I was going to uninstall the toe links, but I'm surprised it's happening on all of your stock cars.

[OF Hero]

OP please let us know what you find....new prospective buyers are interested to hear your results.