Can you spin crank hub by just revving the car?

[maul3d]

Originally Posted by NYG

And how many of them have been tuned, then detuned and sold to a new buyer?

I'm not saying I don't believe that it hasn't happened to a stock car but it is a problem that is almost exclusive to tuned cars.

I'm stock running D3 and doing kick downs every single day + tracking regularly.

Same here. Warrantys good to 2020.. I'm driving this thing like a stolen rental till then.

[noone]

I have 2k on the odo on my 2018 M3 and I'm already wanting a tune. And my warranty doesn't expire until Nov 2022. Scared to get a tune because of this weak link.

[Yessir]

Originally Posted by TRYM3

What exactly is this "kick down" that everyone is talking about? And also is it more likely to happen in a DCT car? My tuner said the only manual cars he has seen it happen to is on an accidental "money shift"

Kickdown occurs when you floor it hitting the button on under the accelerator pedal and down shifting simultaneously. This will put the car in the safest lowest gear for the engine rpm range thrusting you into warp speed.

[minn19]

I heard it can spin just looking at it while stationary.

[ntg44]

Originally Posted by minn19

I heard it can spin just looking at it while stationary.

Came here to write this. Saved me the time.

[NickyC]

Originally Posted by minn19

I heard it can spin just looking at it while stationary.

lol true story.

[DanMpower]

Originally Posted by Wmf80

The unfortunate truth is the tuned vehicle will not be covered under warranty, as the stock will be cover if under warranty.

YMMV with the warranty but it seems like the dealerships will warranty and fix your spun crank hub even if you're tuned granted there isn't damage done to the valves/heads/pistons etc. AND you take steps not to get your car flagged by flashing it back to stock before dropping it off.

The vast majority of the spun crank hubs do not lead to catastrophic engine failures and the fix most of the time involves just retiming the motor with a new crank hub/bolt. All bets are off if you lose a motor while being tuned though since they will deep dive into the car's computer and find out you've been a naughty boy.

The chances of a SCH are so rare and on top of that even rarer to lose a motor because of it, I wouldn't lose sleep over it. Good used S55 long blocks are getting cheaper every day, you can pick one up for $6-7k now, find a good indy shop or DIY and save 75 percent off what BMW would charge in the extremely rare event you do grenade your motor.

[CanAutM3]

Originally Posted by drgmt

The extra power of a tune is exposing the weakest link in a complex chain.

It's clearly way more common in tuned cars - although overall a rare phenomenon. The difference is if it is stock and keeps spinning, you have recourse through BMW and have a strong case for invoking lemon laws if preset in your location. Or at least getting BMW to buy it back end of lease. Otherwise get ready to pay from your pocket.

I am not convinced it is totally related to the amount of power. I think it is mostly related to how fast the engine is accelerated.

[TideMD]

Originally Posted by CanAutM3

I am not convinced it is totally related to the amount of power. I think it is mostly related to how fast the engine is accelerated.

I agree - rapid change in RPM fighting inertia of the linked system. It's really the only thing that seems to make sense.

[jpy1980]

Originally Posted by TideMD

I agree - rapid change in RPM fighting inertia of the linked system. It's really the only thing that seems to make sense.

‘Splain Lucy.

What would be some scenarios that this would happen?

[drgmt]

Originally Posted by CanAutM3

I am not convinced it is totally related to the amount of power. I think it is mostly related to how fast the engine is accelerated.

I suspect the delivery of the power and torque is important

[M Turbo]

Originally Posted by mike@x-ph.com

Agree, thats a price to pay for more fun. But looking at the forum, you get the feeling its happening to every other car when i reality its got to be less than 1%

That is incorrect. Out of 20 cars in my group chat, 5-6 spun. Given all we're tuned.

[rocklobsta1109]

Originally Posted by drgmt

I suspect the delivery of the power and torque is important

I've debated this with my mechanical engineering friends and it doesn't really make sense that the torque load on the front, pully side, of the motor would increase in a very meaningful way in relation to the torque output of the engine.

The torque used to drive the valvetrain and accessories vary with power output but no where near in the range that the output shaft on the rear of the engine experiences.

Without load, revving the engine is among the fasted RPM changes the engine can experience, and I doubt its enough to spin the crank hub, tuned or not.

I'd put money on it being related to kickdown and/or very aggressive upshifts in DCT or money shift in 6 Spd cars. Those are very large and abrupt changes of several thousand RPM nearly instantly and that shock force could be the culprit for the SCH problems

[MuffinFlavored]

I thought there were mods out there to beef up stock crank hub to prevent this problem?

[noone]

Originally Posted by M Turbo

That is incorrect. Out of 20 cars in my group chat, 5-6 spun. Given all we're tuned.

5-6 out of 20 tuned cars you know have spun their crank hub? Those are absolutely terrible odds. Are the 5-6 you speak of more heavily tuned than the ones that have not spun or is the likelihood seemingly random? Any particular build year or mileage correlation or even driving habits that can be made?

[minn19]

Originally Posted by MuffinFlavored

I thought there were mods out there to beef up stock crank hub to prevent this problem?

Yes, which is why a lot of us don't get some of these threads. It is pretty clear that your chances go up quite a bit that if you tune an S55 that you will get the dreaded SCH. So if you do choose to tune, I think it is wise for one to also factor in the money to get one of the solutions that have been on the market for awhile now. But, most just want to tune on the cheap and then when it breaks, complain that BMW isn't warranting their car.

[MuffinFlavored]

Originally Posted by CanAutM3

It still seems to be way more frequent on tuned cars...

This is probably obvious but I just want to make sure it gets said: I would bet that there are a *lot* of stock M3 owners out there who don't know anything about f80.bimmerpost.com, but the majority of people tuning are all over the forums.

Echo chamber...

[MuffinFlavored]

Originally Posted by minn19

Yes, which is why a lot of us don't get some of these threads. It is pretty clear that your chances go up quite a bit that if you tune an S55 that you will get the dreaded SCH. So if you do choose to tune, I think it is wise for one to also factor in the money to get one of the solutions that have been on the market for awhile now. But, most just want to tune on the cheap and then when it breaks, complain that BMW isn't warranting their car.

My biggest question is... who has upgraded their crank hub on a tuned M3 but then *still* spun it? Does upgrading the crank hub make the issue go away?

Like, I have no problem buying what is basically a $2k mod acting as a "insurance policy" to make sure I don't blow up my engine. I don't know who would have a problem with that. :P

It just becomes a weird area where... "I f*cking bought the mod to not have this problem happened... and it still happened!"

Were there same cases of that reported? Upgraded crank hubs still spinning like DJs at a night club?

[mdefalco25]

Let's say we went with a conservative tune to be on par with the Comp package numbers. Would this still be considered a tuned car? I'm asking for a friend

[NickyC]

Originally Posted by mdefalco25

Let's say we went with a conservative tune to be on par with the Comp package numbers. Would this still be considered a tuned car? I'm asking for a friend

Yes, you've modified the stock parameters of the vehicle's engine output.

[jpy1980]

Originally Posted by MuffinFlavored

My biggest question is... who has upgraded their crank hub on a tuned M3 but then *still* spun it? Does upgrading the crank hub make the issue go away?

Like, I have no problem buying what is basically a $2k mod acting as a "insurance policy" to make sure I don't blow up my engine. I don't know who would have a problem with that. :P

It just becomes a weird area where... "I f*cking bought the mod to not have this problem happened... and it still happened!"

Were there same cases of that reported? Upgraded crank hubs still spinning like DJs at a night club?

Yes there seems to be a couple of cars but not on this platform exclusively from my understanding. It’s mentioned on the other crank hub threads. For instance the VTT solution failing on a drag car yet to be fair the drag car didn’t do the full solution and only the partial solution

[DanMpower]

Originally Posted by M Turbo

That is incorrect. Out of 20 cars in my group chat, 5-6 spun. Given all we're tuned.

Originally Posted by M Turbo

That is incorrect. Out of 20 cars in my group chat, 5-6 spun. Given all we're tuned.

Did the 5-6 cars in your group have any engine damage after spinning?