[Apexer]

In the past I talked about this on the m3/m4 general forum but I wanted to bring this topic on the M2 forums as well for the M2C owners .

So I wanted to bring some peace of mind to the people who are very worried about spinning their crankhubs. I have seen people who own stock tune S55’ s and they still worry a lot.

Now don’t get me wrong. I’m not saying the crankhub isn’t the weak part of the S55 engine. If you SOMEHOW spin your CH please don’t blame me. However some people need to chill and in this thread you will find out why.

Apex Motorsport, (@apexmotorsportluxembourg on instagram) is a performance shop that owns a very nice M2C built for track. The car is driven hard on tracks like the Nurburgring and Spa . This M2C runs 500hp+ horsepower and it has done OVER 30.000 KILOMETERS ( or 19.000 miles ) on track. And guess what? It has a stock crankhub. No CBC or anything like that and no problems with the engine. Link to proof photo here :
https://imgur.io/a/TjRf9Im

Still not convinced that your crankhub isn’t made out of paper?

Misha Charoudin is a racing driver and co-founder of the famous Apex Taxi services ( passenger rides ) on
the nurburgring ( not affiliated with apexmotorsportluxembourg btw, just a name coincidence. ) . I’m sure many of you know Misha already. Anyway, in a video posted on Misha’s channel 4 months ago he tells the audience the 2 S55 powered Bmw’ s used by Apex Taxi Services don’t have the crankhub upgrade and will NEVER have it. These two BMW’s (F80 and F82 ) have been tracked for tens of thousands of kilometers on the stock hub with no problems ( AND THE F80 HAS 550HP ). Misha also said how none of the S55 s he knows on Nurburgring have the upgraded hub. They all run stock CH.
- He says all of this in this video at around the 6:10 mark -

: https://youtu.be/j9iSJe_JRgE

In conclusion, there’s countless of stock and tuned S55’s on the Nurburgring driven really hard with no problems on the stock hub. I don’t think you should lose sleep over the CH if you are under 600hp and if you don’t increase the rpm by a lot on downshifts like a dumbass ( for example 4th to 2nd in a 6MT at 50mph or kickdown from a high gear to a low gear in DCT ) . I know there’s completely stock cars out there that spun their hubs (tbh I think less than 500 cars worldwide out of 250.000 S55 s built ) but it usually happens at a very very low mileage which indicates some kind of manufacturing error in my opinion (or some kind of driver mistake like a moneyshift) . We also don’t know the credibility of the people claiming stock SCH. We also don’t know if previous owners tuned these stock cars or not. If you do spin somehow, in 90% of cases you only have to retime the engine and get a new crankhub ( perfect opportunity to get an aftermarket one ) . So stop worrying so much ! This is only my opinion but it s backed up by some solid arguments. I researched this issue for hours. Take this post with a grain of salt I guess .

I really hope this post is relieving for some of you.

Thanks !

Bonus : Autotopnl took a 242k kilometers ( or 150k miles ) F80 M3 S55 on the Nordschleife and Autobahn. Still running strong .

Videos :
https://youtu.be/TuUAJzREg6w?si=en6Ld1NCjcxOdB5Y

https://youtu.be/EKz4TyEPMGM?si=-W2TqRGwAyU28GXn

[m2ss]

I don't worry one bit about it but still believe it's the luck of the draw.

Have there not been spun hubs on stock engines simply due to start ups?

[Apexer]

Originally Posted by m2ss

I don't worry one bit about it but still believe it's the luck of the draw.

Have there not been spun hubs on stock engines simply due to start ups?

I recall there was some SCH after start ups when putting it into gear and moving off. Not sure if any happened right after the start up. It has to do with the CH getting loose for some reason but those really are freak accidents imho or just “bad” crankhubs from factory waiting to explode. Many people reported SCH at 1000-2000 miles/km which clearly suggests that something was wrong with the CH from factory. I also tend to think some people on these forums are lying just to sell aftermarket crankhubs, troll or exagerate the issue but again just my opinion.

[mike@x-ph.com]

[chmura]

I agree, its not a huge problem as the forums portray it to be. My buddy is on Stage 1 since 1,000 miles on the car he track regularly as well, car is 5 years old now. No issues.

Shops and vendors push it to make $$.

[M3R1]

I 99.9% agree with the OP. However I am the .01% freak that thinks he will never win the lottery, but will be the unlucky one. I actually did my rod bearings on my ESS-625 E92 with only 19k on the clock. Having the CH done to a tuned car does "feel" like it should be problem free moving forward. At the end of the day everyone has a threshold of risk they are willing to take. If it keeps you from enjoying the car to it's fullest, go for it. Otherwise, tune it and let her rip.

[m2ss]

Originally Posted by chmura

I agree, its not a huge problem as the forums portray it to be. My buddy is on Stage 1 since 1,000 miles on the car he track regularly as well, car is 5 years old now. No issues.

Whp?

[dead.pixel]

The fact that BMW eliminated the issue in the B58 and S58 doesn’t give me the warm and fuzzies about the S55.

[gnx]

I don't disagree with anything the OP mentions. It's just probability.

I had my rod bearings done on a new to me ESS e93 m3 at 9,000 miles four months ago. It's all a matter of perspective. The cars USP is exactly that, it's low mileage. Would I be ok if something went wrong and i had to scour shops that sell bmw parts for a junk replacement engine? No, I would not. A new short block sells for 22K euro on German internet...

Just yesterday I visited some mechanic that tunes s55 engines. I mean, my car has the 07/18 software version and it hasn't been tuned yet, what have I been waiting for? Well, getting screwed with the OEM output is one thing, but going to stage 1 and then having to search for junkyard replacement engine at some point? No can do. So, he will do the insane hub fix as well.

[Apexer]

Originally Posted by dead.pixel

The fact that BMW eliminated the issue in the B58 and S58 doesn’t give me the warm and fuzzies about the S55.

Eliminating a potential failure point makes sense even if it’s not a huge problem. They probably heard about the issue or maybe the engineers who were responsible for the B58/S58 realized the CH design of the S55 is not the best. They also knew the B58 was going to be the S58 “starting point” and the S58 makes a lot of power and torque. The old crankhub is not really suitable for that engine.

N54 and N55 had the same design but there’s barely any failures ever reported. I believe the S55 stressed this CH design more due to more power, higher rpm and more stress on the hub (more mass - mechanical water pump driven off the crankhub. Also the s55 has 2 HPFPs driven off the vaccum pump which is driven off of the cam which is again tied to the crank hub. N55 has electric water pump. Also more failures are reported on the S55 because it s so easy to make it push big power compared to n54/n55

In the end it’s a personal thing whether you think it s a big problem or not but statistically speaking it’s not a big one ( unless you push for a gazilion horsepower ) and IMHO if you’re not pushing more than 500hp you shouldn’t even think about it . Things get messy over 600 from what I’ve seen .

[D22M2]

Not going to convince me - ask me how I know

[m2ss]

Originally Posted by D22M2

Not going to convince me - ask me how I know

How do you know?

[fourthchirpin]

I trust the experience of a BMW Master Tech that has seen the number of failed crankhubs over anyone.

Thats like saying the Vaccine doesn't harm you because you didn't get harmed lol. Great Logic.

[///MPhatic]

Originally Posted by Apexer

Eliminating a potential failure point makes sense even if it’s not a huge problem.

Eliminating the potential failure is an admission the problem exists.

[Apexer]

Originally Posted by fourthchirpin

I trust the experience of a BMW Master Tech that has seen the number of failed crankhubs over anyone.

Thats like saying the Vaccine doesn't harm you because you didn't get harmed lol. Great Logic.

“Great logic”
You don’t have to trust me . This thread was started to tell an opinion backed up by solid arguments. No need to get offended .

[Apexer]

Originally Posted by ///MPhatic

Eliminating the potential failure is an admission the problem exists.

Indeed. But it doesn’t necessarily mean the problem is huge.

[///MPhatic]

Originally Posted by Apexer

Indeed. But it doesn’t necessarily mean the problem is huge.

It comes down to percentage of owners who have had an issue, and the reason that this will never die is because no one knows the numbers. The vast majority of 1st-owner S55's are unmodified for sure, yet many have had the problem, you can't talk to a single dealer that hasn't dealt with it. The tuning community is small, yet every single tuner knows about the issue, and the after-market has responded. All in all I'd say that if you're going to even own an S55 car you have to do something to mitigate the issue, even if it's stock, it's just prudent. But there are those that want to dance with the devil.

For my part I'm happier with an N55 car because sound is more my style than ultimate power, so I'm the lucky one not having to deal with it.

[chris719]

Originally Posted by fourthchirpin

I trust the experience of a BMW Master Tech that has seen the number of failed crankhubs over anyone.

Thats like saying the Vaccine doesn't harm you because you didn't get harmed lol. Great Logic.

One tech does not see a large enough sample size or random distribution of cars. Only Munich knows the real numbers and they will never talk. People who don't understand how statistics work shouldn't pretend they know what's going on here.

[fourthchirpin]

When a BMW master tech tells you they have seen them fail at stock that's enough for me to get it done personally.

Everyone has a choice some people have paid that price some people didn't. It's a judgement call.

BMW know it was a flawed design of they would have kept the same design imo. That speaks volumes to me.

[fourthchirpin]

Originally Posted by Apexer

Thats like saying the Vaccine doesn't harm you because you didn't get harmed lol. Great Logic.

“Great logic”
You don’t have to trust me . This thread was started to tell an opinion backed up by solid arguments. No need to get offended .

No offense. I'm not vaccinated lol
It's a what ever your comfortable with. You have 1 group saying they have seen them fail. The other group saying it's a myth. Maybe Americans are making more power and exposing the flaw. I dunno.

[Apexer]

Originally Posted by ///MPhatic

It comes down to percentage of owners who have had an issue, and the reason that this will never die is because no one knows the numbers. The vast majority of 1st-owner S55's are unmodified for sure, yet many have had the problem, you can't talk to a single dealer that hasn't dealt with it. The tuning community is small, yet every single tuner knows about the issue, and the after-market has responded. All in all I'd say that if you're going to even own an S55 car you have to do something to mitigate the issue, even if it's stock, it's just prudent. But there are those that want to dance with the devil.

For my part I'm happier with an N55 car because sound is more my style than ultimate power, so I'm the lucky one not having to deal with it.

I think perspective plays a big part on it.

Depends if you want to see the good side or the bad side. Many may mean little to some or vice versa .

By browsing the forums you can see many users claiming they have asked their local dealers about the problem and the dealers didn’t even know the problem existed or very few cases of SCH .

The tuners knowing is great in fact they should know the flaws about the engine they’re gonna mod. Like I mentioned previously making power on the S55 is so easy and more power definetly increases the chances of the problem occuring ( that is confirmed by SCH on tuned n54 s and n55 s because stock power spins are very very rare ) . If you get around 550hp I understand having the CH problem in your mind but being stock completely and worrying about it is just pointless from my point of view. 600hp+ is definetly a danger zone.

A stock spin probably has a simillar chance of occuring like failure of other major engine parts like rod bearings or turbos ( not that those are known as problematic ). Stock spins definetly happen a lot at very low mileage like 1000-2000 miles/km suggesting manufacturing error. Why worry about it? That’s like worrying permanently about being ramed on the road by some drunk driver and being so afraid that you stop taking your car out. Again my point of view.


90% of the S55 tracktools driven hard on the nordschleife have stock hubs ( stock power, tuned, dct and manuals ) . If you don’t believe me ask the owners and Misha Charoudin himself ( in fact he said he doesn’t know anyone tracking with a pinned hub s55 many times ) In the original post there is an imgur link showing how someone tracked a M2 Comp 35k kilometers or 19k miles with 520hp on a stock hub and still going strong.

And again I’m only trying to say the problem is not huge. I’m not saying it’s not an issue but I already mentioned that in the first post.

[bimmerdriver2]

Originally Posted by dead.pixel

The fact that BMW eliminated the issue in the B58 and S58 doesn’t give me the warm and fuzzies about the S55.

To be fair, the B58 and S58 have the timing chain at the rear of the engine, so they could not have done it any other way. On the N55 and S55, it would not be possible to change the timing chain without removing the crankshaft if the hub wasn't removable, because the timing cover is integrated with the engine block.

(Not making excuses for BMW. There was nothing stopping them from designing a positive fastening mechanism for the hub and sprocket if had they chosen to do so.)

Something I've wondered, but not seen an objective analysis, is whether or not a capture mechanism is a "good enough" fix, even if it's not the best possible fix. It's pretty clear that if the torque applied to the sprocket in the direction that loosens the crank hub bolt, that could result in the hub and sprocket spinning. If the sprocket only spins when the crank hub bolt is loosened, then perhaps a capture mechanism is "good enough". If the reason for the sprocket spinning is because it overcomes the friction of the washer and destroys the washer, then a capture mechanism is insufficient. If anyone can point to an analysis of this, please let me know.