[Apexer]

Originally Posted by M3R1

Just an FYI, ACM is my shop of choice and they had a bone stock M2cs spin. The car was in fact a DCT, but rather than bring it to the dealer, he elected just to do the fix.

Do you know the mileage of the car?

[///MPhatic]

Originally Posted by Apexer

I mentioned Misha because he knows everyone and everything at Nordschleife. If it was a big issue he would know.

That's laughable.

Misha doesn't know the smallest fraction of S55 owners, nor does he keep track of the problems they might have.

[Boysie56]

Originally Posted by Apexer

Here in Europe you almost never hear about failures and I don’t know any personally. It’s kinda interesting .

Plenty of failures here in the UK, my friend runs a performance car garage and has seen many fail. Upgraded 4 pin solid hub, problem solved.

[Apexer]

Originally Posted by ///MPhatic

That's laughable.

Misha doesn't know the smallest fraction of S55 owners, nor does he keep track of the problems they might have.

Laughable…

It’s not about how many he knows. It’s about the percentage. Let’s say he knows about 20 S55 cars tracked hard. If none of those had the failure then what is the failure percentage ? 0% Of course if you take all the S55 s there then there might be a failure or two, but that just proves the problem isn’t as big as it seems ( the whole point the thread was started ) .

He filmed many videos with S55 M cars. He always asks about mods done to the cars by the owners. He’s got many friends there. The S55 taxis at Apex where Misha is a co founder (M3 and M4 ) both run stage 2 with the stock crankhub and they were tracked for hundreds and hundreds of laps and driven by pros at the limit. This is what I mean when I say Misha knows some stuff around the Nordschleife .

No one was rude to you in this thread but in previous replies you claimed people want to pick fights with you. The problem is the way you reply. For example the fact you said my opinion is laughable is not that kind. You can disagree but I don’t understand what you’re trying to accomplish by disagreeing in a rude manner. I don’t care to be honest but I’m just saying. Anyway I’m not here to teach good manners.

Thanks and have a good day.

[///MPhatic]

Originally Posted by Apexer

Laughable…

To suggest that a single person knows a significant percentage of M2 S55 owners just isn't realistic. I agree that Misha knows a lot of people, but reasonably you have to side with the number here. And again, even the guys he has spoken with would not always divulge these things, and BMW certainly will not because of a possible class-action.

It's just not possible to get these numbers, and even if we could we'd have to really dig deep into them with regards to mileage, mods, etc, to establish causality. It's just not feasible, and I would think that's pretty obvious. My apologies if I was rude, I just think the whole thing is obvious if you think about it for 2 minutes.

BMW has the most/best information here, and they may not even know the exact cause, but they don't have to, they just have to change the design, which they did.

[Apexer]

Originally Posted by ///MPhatic

To suggest that a single person knows a significant percentage of M2 S55 owners just isn't realistic. I agree that Misha knows a lot of people, but reasonably you have to side with the number here. And again, even the guys he has spoken with would not always divulge these things, and BMW certainly will not because of a possible class-action.

It's just not possible to get these numbers, and even if we could we'd have to really dig deep into them with regards to mileage, mods, etc, to establish causality. It's just not feasible, and I would think that's pretty obvious. My apologies if I was rude, I just think the whole thing is obvious if you think about it for 2 minutes.

BMW has the most/best information here, and they may not even know the exact cause, but they don't have to, they just have to change the design, which they did.

I respect your view on it. I never claimed Misha knows a significant percentage of S55 Owners. In the end it’s a personal thing whether you believe it’s a big issue or not.It definetly exists and there is countless of factors to take in consideration when debating this subject.

On the B58/S58 the timing chain is at the back of the engine and we will never know for sure if the crankhub design changed because of the timing being behind or not ( maybe they decided to put it behind because of the crankhub failures, who knows ) But if the S58 had this crankhub design there is a high chance it would have been a big problem due to the power.

[m2ss]

Originally Posted by Apexer

But if the S58 had this crankhub design there is a high chance it would have been a big problem due to the power.

Yup, Mo Power Mo Problems...

[Apexer]

Originally Posted by Apexer

I respect your view on it. In the end it’s a personal thing whether you believe it’s a big issue or not.It definetly exists and there is countless of factors to take in consideration when debaring this subject.

On the B58/S58 the timing chain is at the back of the engine and we will never know for sure if the crankhub design changed because of the timing being behind or not ( maybe they decided to put it behind because of the crankhub failures, who knows ) But if the S58 had this crankhub design there is a high chance it would have been a big problem due to the power.

Also B58 ( the engine that the S58 was based on ) was released in 2016 without the crankhub design only 2 years after the S55. I don’t think there were that many failures in those 2 years to make BMW change the design, but no one knows. I can be wrong and I know that.

[chris719]

Originally Posted by Apexer

Laughable…

It’s not about how many he knows. It’s about the percentage.

Take a step back and think about it. What if track use actually decreases the risk? There aren't violent kick downs, clutch drops, and drag racing on the ring. It's quite possible that the people that use S55 cars as track tools instead of driving like a nut on the street are actually at lower risk, which means this sample size Misha sees is biased.

[Apexer]

Originally Posted by chris719

Take a step back and think about it. What if track use actually decreases the risk? There aren't violent kick downs, clutch drops, and drag racing on the ring. It's quite possible that the people that use S55 cars as track tools instead of driving like a nut on the street are actually at lower risk, which means this sample size Misha sees is biased.

Definetly a possibility. If that’s the case it just shows that if you drive these cars the way you’re supposed to then the chance is way smaller for something bad to happen.

[imperfectluck]

Originally Posted by Apexer

Definetly a possibility. If that’s the case it just shows that if you drive these cars the way you’re supposed to then the chance is way smaller for something bad to happen.

I side with you though the appeal here in The States is that the vast majority just love to haul ass in a straight line and are nervous when corners are introduced.

Admittedly, I tend to judge if you’re past stage 1 power and you’re still sitting on stock suspension or “lowering springs.”

[M3R1]

Originally Posted by Apexer

Do you know the mileage of the car?

The mileage was low, however I am not sure.

[dead.pixel]

Originally Posted by Apexer

One thing I haven’t mentioned in this thread is fuel quality. It might increase the chance of a spun crankhub.

In America the fuel is not great, hence the conservative tunes from factory ( american market cars always have less hp than the european ones ) . I wonder if the bad fuel can cause some bad harmonics/vibrations and slightly increase the chances to mess up the crankhub.

I think you are confusing SAE vs Metric horsepower. The vehicles make the same power.

[///MPhatic]

Originally Posted by imperfectluck

I side with you though the appeal here in The States is that the vast majority just love to haul ass in a straight line and are nervous when corners are introduced.

Admittedly, I tend to judge if you’re past stage 1 power and you’re still sitting on stock suspension or “lowering springs.”

I mean, I'm not that guy, but the person that buys the car gets to choose how they use the car. Imagine the horror that Toyota felt when the 2JZ became the bolt-on roll-race king of the US streets, but hey, those guys paid for the car so they get to use it how they intend.

Put me also in the camp that thinks the F80/F82/F87 wasn't meant for actual racing, it's too damn big and top heavy. Of course, I would say that since my other car is an Exige, but still, let them haul ass in a straight line with springs only, it is what it is.

[imperfectluck]

Originally Posted by ///MPhatic

I mean, I'm not that guy, but the person that buys the car gets to choose how they use the car. Imagine the horror that Toyota felt when the 2JZ became the bolt-on roll-race king of the US streets, but hey, those guys paid for the car so they get to use it how they intend.

Put me also in the camp that thinks the F80/F82/F87 wasn't meant for actual racing, it's too damn big and top heavy. Of course, I would say that since my other car is an Exige, but still, let them haul ass in a straight line with springs only, it is what it is.

By all means of course they decide how to use it, I just appreciate a good suspension on a car especially when additional power is thrown at it, we know how coils can make the stock unpredictable manner F8x suspension work. Some people race alone just changing the suspension as with the Nitron system and no power added.

I do find it a bit funny you mentioned the F8x wasn’t meant for racing yet I see a lot of track built ones doing very well in their segment. Was even surprised when I saw the M4 GTS I believe it was impress Mischa on The Ring in a Turbo S.

Coils definitely affect how you put down the power, I never forgot the day when I understood how they factored into launching off a straight and understood the hype of why everyone praised moving from the stock suspension to some form of an adjustable setup.

I like power, I love controlled power more.

[M2_MEDUSA]

I mean.. I had a 2021 S55 spin the hub just by turning the car on. 12,000 miles. 520hp. Never launched, Never used kickdown. Turned the car on and boom. It's fixed now and making well over 600

[MR RIZK]

Same issue on the NC Miata’s and they key the crank to lock it in place as the friction disc is not sufficient.

Albeit for cars that are driven hard, more power and hard shifting etc.

[Reddevils7]

Originally Posted by M2_MEDUSA

I mean.. I had a 2021 S55 spin the hub just by turning the car on. 12,000 miles. 520hp. Never launched, Never used kickdown. Turned the car on and boom. It's fixed now and making well over 600

How hard had you driven on the last drive before you started it up again? Shame it happened but glad you're back up and running again. What aftermarket solution did you go with?

[doughboy]

I've heard about a few spun hubs on startup.

Makes sense as the action of starting the engine is a pretty violent / instantaneous crank acceleration from standstill against the stationary valve train, all in the "undo" torque direction of the hub.

[chris719]

Originally Posted by doughboy

I've heard about a few spun hubs on startup.

Makes sense as the action of starting the engine is a pretty violent / instantaneous crank acceleration from standstill against the stationary valve train, all in the "undo" torque direction of the hub.

I doubt it's that. If it's related at all it's probably because once the engine cools the metal contracts and less pressure is exerted on the failing friction disc. The dRPM/dT from a start is not high compared to operation.

[doughboy]

Equal and opposite all things being equal. The hub may contract when cooling so reducing clamp force, but also the bolt will contract increasing clamping force.

The dV/dT is pretty high starting from zero V and over a very small T. And the static friction of the valve train is very high.

Whereas revving an already rotating engine from say 2000-6000 rpm by throttle action will be more gentle.

But agree, generally the more violent effects of harsh DCT downshift or manual money shift are likely worse.

[chris719]

I suppose it depends on the coefficient of thermal expansion of the washer vs the rest of the metal.