[F87source]

Originally Posted by SpecialEdition_F87

To everyone's point yes, I was tuned and modified. Roughly was only 530whp and 560wtq during its time. So about 580hp 600tq to the flywheel. I'm here to provide data.

I hope we can take something away from this.

1. I have never once used kickdown in the vehicle and there's many posts about people arguing kickdown causes the spin. (debunked)
Can it accelerate it? Maybe?? But this spin should put all that kickdown to rest. You'll still spin it if your tuned

2. I have never launched the car, I have never tracked the car. However yes I do accelerate and race the car on a closed course. 90% of the cars life is spent commuting to work. The other 10% is spent enjoying the car and ripping on it

3. 2021 s55 have done nothing to adress the fix and I'm unsure if that's been verified yet. I know 2020 have been verified to no crankhub update. This spin should set in stone 2021 hasn't either.

4. I have never taken the car past 7,000 rpm in the past 10,000 of it's 14,000 mile life. Mainly cus it just falls flat. Take this data how you wish….

Lemme end with this, If you are tuned you are simply playing with fire. And just because your car hasn't seen a spun crankhub doesn't mean it hasn't already slipped and knocked camshaft timing off slightly but still within tolerance. The further it slips out the worse it gets.


After breaking down the motor we seen signs of the camshaft timing slowly moving further and further over the course of a few months. This could be happening to your s55 as we speak. And you won't even know it. I didn't. So be careful and get it done. Living life on a wish and a prayer isn't worth it. Suck it up pay the 1,800-2,200 and move on

Kick down exacerbates the issue, it is not the sole cause of it - and that has already been known.

The cam position sensor is sensitive down to fractions of a degree, there is no way it slips progressively over time if it slips it slips. There is no way to differentiate between a slip that occurs over time and one that occurs instantly by looking at scoring. But since the crank and cam angle sensors are so sensitive it can be reasonably assured that as soon as timing is slipping you will know about it, it won't occur over time slowly - if it breaks the coefficent of friction on the friction disk on the hub and slips it slips and permantly damages that washer meaning it will not be able to hold anymore, there are not partial slips.

[M2_MEDUSA]

Originally Posted by F87source

Kick down exacerbates the issue, it is not the sole cause of it - and that has already been known.

The cam position sensor is sensitive down to fractions of a degree, there is no way it slips progressively over time if it slips it slips. There is no way to differentiate between a slip that occurs over time and one that occurs instantly by looking at scoring. But since the crank and cam angle sensors are so sensitive it can be reasonably assured that as soon as timing is slipping you will know about it, it won't occur over time slowly - if it breaks the coefficent of friction on the friction disk on the hub and slips it slips and permantly damages that washer meaning it will not be able to hold anymore, there are not partial slips.

Got ya, your probably completely correct on all of that. it's quite interesting because my car got progressively slower and slower within the last month of me driving it. Maybe it did fully spin as bad as it looked. But they said they've never seen an s55 be so far outside of camshaft timing. I'm surprised my valves are fine. Moving forward they pulled it out popped it in fresh spark plugs and I was back on the road. Car is crisp and it moves as fast as it did awhile ago. This is measured off 60-130 times. Quite interesting how the car progressively lost power overtime if there is no slip. Every part of the motor has a tolerance even sensors.

One thing that it could be is the JB4 may have hid the codes for so long because maybe it changes the parameters of everything? So maybe it was outside of tolerance and it never populated until recently.

Either way it's in it's over with now I can grab a set of turbos. I turned it up today finally since I got the crankhub put in. She hauls ass

[F87source]

Originally Posted by SpecialEdition_F87

Got ya, your probably completely correct on all of that. it's quite interesting because my car got progressively slower and slower within the last month of me driving it. Maybe it did fully spin as bad as it looked. But they said they've never seen an s55 be so far outside of camshaft timing. I'm surprised my valves are fine. Moving forward they pulled it out popped it in fresh spark plugs and I was back on the road. Car is crisp and it moves as fast as it did awhile ago. This is measured off 60-130 times. Quite interesting how the car progressively lost power overtime if there is no slip. Every part of the motor has a tolerance even sensors.

One thing that it could be is the JB4 may have hid the codes for so long because maybe it changes the parameters of everything? So maybe it was outside of tolerance and it never populated until recently.

Either way it's in it's over with now I can grab a set of turbos. I turned it up today finally since I got the crankhub put in. She hauls ass

Did you have jb4 auto clear on? Even then I'm pretty sure it cannot clear drive train malfunctions just generic obd2 codes. So I don't think it would hide the fact timing has slipped. So not sure why your car got slower, but generally piggy backs never provided me with good consistency.


Yes every has a tolerance range, but the angle sensors are good down to .1 of a degree so that's very very very accurate, and any slip will be caught.

[Will Delarosa]

Originally Posted by SpecialEdition_F87

2021 S55 with 14k miles. I spun the hub today on my way to install an upgraded crankhub. How unlucky can a single human be. I turned my car on and immediatly got most of the codes. Drive train malfunction and car would make any boost. Car was in park still so when it turned over that force spun the hub I'm assuming it was already loose. PSA to anyone with 2021 S55 it's still an issue. Upgraded hub going in right now. Timing was severely off. We pulled the hub from the car and it was scored heavily indicating a confirmed slip/spin. I have you know I have never used the kickdown feature. All that garbage about the kickdown is false. Doesn't matter what you do. You will most likely spin the hub if you tune the car.

Man I just Installed the VTT hub myself so much work but so glad it's done definitely a must if you plan on tuning!!!! [IMG][/IMG]

[M2_MEDUSA]

Another data point, I been thinking about how I have been driving the car and wanna unload as much info as possible.

I may not have taken it past 7000 rpm when accelerating however it dawned on me that I always manually downshift the car and many times the car would downshift to about 5-6k rpm a lot. I presume this is reverse torque and a main accelerant of the spun hubs. This common practice of mine could have been the accelerator of my spun hub. I can't confirm it however I'm happy to share this data with everyone

[M2_MEDUSA]

Originally Posted by Will Delarosa

Man I just Installed the VTT hub myself so much work but so glad it's done definitely a must if you plan on tuning!!!! [IMG][/IMG]

Nice! Yes my hub is in now also. It feels so good. Car drives amazing. Can't believe you took on such a big project with no previous experience on this job. Great work. What are your thoughts so far? I also went with the full vargus V2 spline lock. Haven't heard of any cars failing on them other than manuals with no cbc. I hope you installed the crank bolt capture as well

[Apexer]

I saw people running multiple trackdays with a stage 1 tune and nothing happened. This is so weird I can’t really comprehend it. Maybe running a tune with a progresive torque curve helps? I don’t know. Anyway I’m glad your car is running happily .

[Apexer]

I believe the BMW M4 GT4 runs an oem crankhub and runs laps after laps for hours and nothing happens. Weird .

[m0g24]

Guys, do you think this is worth worrying about if we don't run tune? I plan on keeping my car stock but the stories with crank hub seem endless

[ROBM2C]

^^^ I'm doing it just for piece of mind , but while it's getting done a tune will be thrown on …might as well .

[ZL9M2]

I don't know why you wouldn't immediately do the crank hub when you tune. That seems to be the issue.

[akkando]

Originally Posted by m0g24

Guys, do you think this is worth worrying about if we don't run tune? I plan on keeping my car stock but the stories with crank hub seem endless

Not if you're still under warranty.

[warrenw]

Originally Posted by m0g24

Guys, do you think this is worth worrying about if we don't run tune? I plan on keeping my car stock but the stories with crank hub seem endless

That's because a lot of people tune

I'm in Korea, track with a ton of S55 folks, and no spun hubs. Nobody even does crank hub fixes here either. All those N-Ring cars in Europe? Vast majority don't do it either.

[chris719]

I still am not sure what to think. Other than highly tuned cars, this does seem like a failure that happens early in the life of stock and lightly tuned cars. Perhaps most of the failures are destined from the beginning and would happen tuned or not. We have seen this on low mileage stock S55s. It doesn't feel like the rate is any lower on M2C than F8x ZCP or the CS models. Perhaps it's not related to the power output until you hit extremes. No idea really, just a theory and we'll never have the data clear enough to find out.

Is M GmbH really this impenetrable? You would think that an insider would have leaked the root cause years ago.

[Apexer]

Originally Posted by m0g24

Guys, do you think this is worth worrying about if we don't run tune? I plan on keeping my car stock but the stories with crank hub seem endless

No I wouldn’t . Stock cars who spun their hub did so because of factory error. No other possible reason because every case of stock crankhub spin I’ve seen was during break in miles or right after ( basically very low mileage ) . I’d probably go for a low torque tune as well with the stock crankhub. There are more people that didn’t spin theirs than the ones who did on a tune from what I’ve seen. Just my take on it .

[Apexer]

There is some guy with a BMW M2C on youtube who has been running a stage 1 on stock crankhub for a few months . He tracks his car at the nurburgring and he doesn’t have any issues . Each with their luck. I’ve seen M4 ‘s with 650hp with no issues as well .

[Steelguin]

Rule I was told years ago, if you want to tune or go FI on a NA car make sure you have money set aside to replace the engine.

[M2_MEDUSA]

Hey guys yeah the spun crank hub issue may or may not happen immediately but if your tuned it's a ticking time bomb. I too have seen my fair share of 550-600whp s55 motors with no spun hub see abuse day in and day out on the track. Some of those cars eventually spun… blues clues M3 for example. It may be ripping on the track now but soon the fun comes to an end.

When you tune the vehicle whether you like it or not you are going outside of factory tolerance. When your outside of that tolerance bad things happen. This is unfortunately the weak point. These are strong motors and can handle upwards of 800hp before rods and pistons needs addressed. These are beautiful cars when tuned and I hope everyone experiences the level of power these motors can produce with a strong tune. Just do it right. And do it with a crankhub. I myself denied it and always said " it's such a small percentage, chances are slim " I was wrong.

If your stock and under warranty don't worry about it. If your tuned, it's a matter of time and hopefully you sell the car before it's your turn to face the music. Do your crankhub and forget it.

[Ratcher]

Originally Posted by SpecialEdition_F87

Update there is nothing wrong with the valves. No impact. We replaced the hub. It's incredible How the hub slipped while Parked. Just turning the car on

That's not really incredible, it has been known to be one of the most common ways of it happening.

[Ratcher]

Originally Posted by SpecialEdition_F87

Another data point, I been thinking about how I have been driving the car and wanna unload as much info as possible.

I may not have taken it past 7000 rpm when accelerating however it dawned on me that I always manually downshift the car and many times the car would downshift to about 5-6k rpm a lot. I presume this is reverse torque and a main accelerant of the spun hubs. This common practice of mine could have been the accelerator of my spun hub. I can't confirm it however I'm happy to share this data with everyone

Yea downshifting is the most common trigger for a spin iifc

Originally Posted by SpecialEdition_F87

I hope you installed the crank bolt capture as well

That is literally the biggest scam in the S55 aftermarket industry. Does absolutely nothing to hinder a spin.

The one piece crank hub is all you need

[M2_MEDUSA]

Originally Posted by Ratcher

Yea downshifting is the most common trigger for a spin iifc

That is literally the biggest scam in the S55 aftermarket industry. Does absolutely nothing to hinder a spin.

The one piece crank hub is all you need

Your completely incorrect. The one piece hub doesn't address the bolt. If the bolt backs out your one piece hub ain't doing anything.

$100 and 45 min of work is far from a scam. But keep believing that

By the way all the data in the market proved your claim completely false! Not a single spun hub has ever beeen reported outside of a moneyshift when crank bolt capture has been installed under 600/600. Data proves you completely incorrect.

[2020m2c]

Originally Posted by SpecialEdition_F87

Hey guys yeah the spun crank hub issue may or may not happen immediately but if your tuned it's a ticking time bomb. I too have seen my fair share of 550-600whp s55 motors with no spun hub see abuse day in and day out on the track. Some of those cars eventually spun… blues clues M3 for example. It may be ripping on the track now but soon the fun comes to an end.

When you tune the vehicle whether you like it or not you are going outside of factory tolerance. When your outside of that tolerance bad things happen. This is unfortunately the weak point. These are strong motors and can handle upwards of 800hp before rods and pistons needs addressed. These are beautiful cars when tuned and I hope everyone experiences the level of power these motors can produce with a strong tune. Just do it right. And do it with a crankhub. I myself denied it and always said " it's such a small percentage, chances are slim " I was wrong.

If your stock and under warranty don't worry about it. If your tuned, it's a matter of time and hopefully you sell the car before it's your turn to face the music. Do your crankhub and forget it.

Sorry this happened to you but that's not quite how odds work. Tuning may or may not increase the odds (unfortunately only BMW has any real robust data set on this). Even IF tuning increases the odds of it happening we don't know by how much and to what extent the preventative upgrades prevent slipping.

I take issue with saying "it's a matter of time". You simply don't know that with any certainty and what little data is available contradicts this. Truth is these motors don't seem to be failing by the thousands despite how many copies of BM3, JB4, etc are being used in the open market. Your statements about this issue are colored by your recent experience. In simplest terms it's what is known as reverse survivorship bias.

A true pro forma to evaluate the cost / benefit of a clutch hub upgrade would need to evaluate how often they spin, how often each clutch hub upgrade still fails, what the average and range of the cost of repair of a spin is (timing, hub replace, full motor, etc), and the cost of the upgrade. Of course you'd need to evaluate the various options available to figure out if some or any of them were really worth it based on how much they prevented (or exacerbated) the damage. And yes, there is some thought that the damage is more catastrophic when an "upgrade" fails violently rather than a slight slip of the stock hub.

Most of that data is unavailable to us so really this is a case study. Purely anecdotal and not actionable to the S55 motor writ large. Again, sucks that it happened to you but for me it's a small risk to begin with and a lot of marketing hype based on what *appears* to be a marginal amount of failures of the S55. The problem is that if you are one of the unlucky few it hurts bad. I just don't know that the expensive "fix" is really good insurance per dollar or not. I guess if it happens to mine it will be 100% a problem, and if it doesn't then it's 100% a win. Roll the dice…