[M2_MEDUSA]

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.

[Wakka]

Are you not under warranty?

[M2_MEDUSA]

Originally Posted by Wakka

Are you not under warranty?

Warranty isn't gonna affect the hub, cus it'll still spin. I was on the way to upgrade it to a better crankhub and it spun. New upgraded crankhub just went in.

[Tag]

He meant why not get it looked at under warranty first to make sure there is no other damage before you drop more time and $$$ into the upgrade.

[ChrisK]

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.

What tune do you have?

[F87source]

Originally Posted by Tag

He meant why not get it looked at under warranty first to make sure there is no other damage before you drop more time and $$$ into the upgrade.

Because he's tuned, warranty is done.


Sorry this happened to you OP, but it is a common issue once tuned. BTW did you end up getting the CBC?

[M2_MEDUSA]

Originally Posted by F87source

Because he's tuned, warranty is done.


Sorry this happened to you OP, but it is a common issue once tuned. BTW did you end up getting the CBC?

I bought it back way before break in miles and never installed it. I wish I did. I didn't care, if the valves bent I will just build the head and port it. But so far looks like nothing major so not needed.

[6speed_M2]

If the car is tuned it makes more sense. The S55 makes crazy torque with a tune.

Sorry to hear OP. The timing is wild with everything you mentioned. Hopefully there's no other damage so fingers crossed.

[F87source]

Originally Posted by SpecialEdition_F87

I bought it back way before break in miles and never installed it. I wish I did. I didn't care, if the valves bent I will just build the head and port it. But so far looks like nothing major so not needed.

Yeah that sucks, hope you get it fixed.

[m0g24]

Yikes this is frightening... I have a final week build 2021.

Do you guys really think those who are stock/untuned are fully in the clear? Sorry to read these were the cards dealt to you OP.

[F87source]

Originally Posted by m0g24

Yikes this is frightening... I have a final week build 2021.

Do you guys really think those who are stock/untuned are fully in the clear? Sorry to read these were the cards dealt to you OP.

No, there's always a chance albeit small, that you'll soon the crank hub on a stock car.

[M2_MEDUSA]

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

[SEAT TIME RULES]

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

As I've mentioned in several other SCH threads, the chance of a SCH is low, and if you do end up in that small percentage the chances of spinning the hub enough to damage your exhaust valves is even smaller.

Glad all you had to do is realign the CH and reinforce it with a Aftermarket kit.

[Mr Pete]

Oof thank goodness no further damage outside of the hub. Sucks to have to deal with this.

[CoffeeLife]

Caused by JB4?

[M2_MEDUSA]

Originally Posted by SEAT TIME RULES

As I've mentioned in several other SCH threads, the chance of a SCH is low, and if you do end up in that small percentage the chances of spinning the hub enough to damage your exhaust valves is even smaller.

Glad all you had to do is realign the CH and reinforce it with a Aftermarket kit.

Yeah I used to always say it's low too, but then it happens to me. I believe it's best to just do the hub. If you get the hub on like Black Friday from vargus it'll run you about 4 hundred bucks. Then labor is anywhere from 1300-1600 at the right shop. Shop I went to did same day turn around and car is crisp so happy.

[M2_MEDUSA]

Originally Posted by CoffeeLife

Caused by JB4?

Well caused by tune. Either tune doesn't matter.

[M2_MEDUSA]

Originally Posted by Mr Pete

Oof thank goodness no further damage outside of the hub. Sucks to have to deal with this.

Yeah man it sucks. Especially since I was being proactive and doing the hub as preventative. I get in my car cus I'm headed to my crankhub appointment to get ahead of the game and I turn the car on and wham! Talk about bad luck

[Mr Pete]

Originally Posted by SpecialEdition_F87

Yeah man it sucks. Especially since I was being proactive and doing the hub as preventative. I get in my car cus I'm headed to my crankhub appointment to get ahead of the game and I turn the car on and wham! Talk about bad luck

Dude that's the worst luck. But at least it didn't happen while driving putting you in harm's way. This is the type of shitty luck that always happens to me lol get back on the road after it's fixed and enjoy the car again! Hopefully soon enough!

[FaRKle!]

Guys, this car is (JB4) tuned, meth'd, and apparently street raced regularly. It's not a case of "stock power hub slipped," and shouldn't be terribly surprising. I concur that it's fortunate this showed up at start up and not during driving.

Originally Posted by SpecialEdition_F87

JB4 is the best tune for the money right now, Every other tune is a waste of money. Go JB4 and don't look back. Enjoy 530whp on map 7(:. Drives exactly like stock and have 7 different maps to play with. And you'll smack any OTS flash tune S55 running map 7. Map 2 is a great daily map tho.

Originally Posted by SpecialEdition_F87

Your not gonna see that number to the wheels on any piggyback other than a JB4. Carbahn is very conservative and your mainly paying for the warranty it provides. So numbers are lack luster. Rn I'm running JB4 on a 2021 M2C and on map 8 you will see 600+ crank hp roughly 560 wheel hp and 650 tq to the crank roughly 610 wtq. Only thing that's annoying about carbahn is there's 1 map. Why not purchase a piggyback where you can utilize 8 different maps for different styles of driving/fuel and air quality Rather then just a 1 size fits all piggyback !? If your going for warranty that carbahn provides go carbahn. If you want power and flexibility in all environments and fuels go JB4.

Originally Posted by SpecialEdition_F87

Nice! I'll be running the BMS kit. I ran the snow performance kit on my 428 and loved it. I went with M1 and mixed my own distilled water with it for a 70/30 or 80/20. I just got the crankhub so I'll be running 28psi on the stock turbos hoping for 560-570 wheel. Beautiful dyno curve btw. Holds power. Almost looks like the stock curve but with more power. Is this what you were going for?

[SchnellerM2C]

Group,

Just adding my 2 cents here...

While I personally haven't seen this happen to an s55, I have seen it happen on other BMW engines, usually in track or race cars.

High revs coupled by a reverse load of the drivetrain (wheel road speed driving the motor) as would happen with an abrupt throttle lift at redline, or by selecting 3rd gear instead of 5th from a 4th gear upshift, will either cause a crank hub to spin, or at least loosen the crank hub bolt enough over time for it to spin loose later, even under less aggressive conditions.

We witnessed this on an S52 engine where the driver almost completed the 4th to 3rd (instead of 5th) "money shift" but caught himself and everything was fine...Except, during the next session, under brisk acceleration, the hub did spin.

Certainly more power via a tune will help the process along as more forces are involved, pushing the limits of the design envelop.

If you have a highly tuned car, a better hub design is likely a good idea. If your car is stock, watch those money shifts and be sure to select the right gear for the given road speed. Rev matching (heel/toe), especially if you've coded it out of your car is important as wheels driving the motor will also do a great job twisting up clutch pressure plates too.

[M2_MEDUSA]

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. If you are stock don't worry about it. To the tuned hopefuls it's a matter of time. Regardless I'll put money on the fact that your car has already begun to slip. You might get lucky and it never will fully spin but with this motor it'll start slipping and you will have zero clue.