N54 crank hub issue - power level?

[Rob09msport]

So are auto a little safer than manual and dct ?

 

[Traf]

Manual shifts the slowest so it should be safer.
A friend of mine had his hub slip when his DKG kicked down.

 

[Rob09msport]

The actual total process is slowest but the rev drop is by far the harshest and I think the ratios are further apart that's talking out my ass though.
But look at guibo and tranny mounts auto holds up stick not so much

Edit I should say has the potential to be harshest. Especially a money shift or something.

 

[Hydra Performance]

Autos should be "safer" than manuals as the torque converter cushions shifts a little. Agree that DKG/DCT is the most risk-prone tranny out there. Also keep in mind that the S55 has a belt-driven water pump adding a bit of load onto the hub, in addition to being inherently torquier

 

[Rob09msport]

Autos should be "safer" than manuals as the torque converter cushions shifts a little. Agree that DKG/DCT is the most risk-prone tranny out there. Also keep in mind that the S55 has a belt-driven water pump adding a bit of load onto the hub, in addition to being inherently torquier

And 90 percent dct
With factory shift speed control

 

[Optigrab]

Autos should be "safer" than manuals as the torque converter cushions shifts a little. Agree that DKG/DCT is the most risk-prone tranny out there. Also keep in mind that the S55 has a belt-driven water pump adding a bit of load onto the hub, in addition to being inherently torquier

Do you know if your bolt backed out or the disks just slipped?

 

[Hydra Performance]

Do you know if your bolt backed out or the disks just slipped?

I have a VTT bolt capture so I'm guessing the latter

 

[martymil]

Manuals would be the safest pending what clutch/flywheel combo you use on the n54.

Haven't seen or heard of a manual s55 crank hub slip yet but seen a few DCT.

 

[Optigrab]

I have a VTT bolt capture so I'm guessing the latter

Dang that makes this even more tragic

 

[Hydra Performance]

Dang that makes this even more tragic

With great power comes great responsibility I guess lol

 

[Rob09msport]

How much torque and hp would you say your putting down

 

[Optigrab]

Manuals would be the safest pending what clutch/flywheel combo you use on the n54.

Haven't seen or heard of a manual s55 crank hub slip yet but seen a few DCT.

There have been a few manual cars but who knows if it was just a money shift

https://f87.bimmerpost.com/forums/showpost.php?p=23774628&postcount=28

 

[martymil]

I have a VTT bolt capture so I'm guessing the latter

Did you use a new crank hub, grip disk and bolt or reuse your old ones ?

 

[Hydra Performance]

How much torque and hp would you say your putting down

I was still only running 17.0psi at the time believe it or not, but was in 2nd gear and hit the limiter abruptly. The rate of change of engine acceleration was pretty violent, as it lit up the tires as soon as the turbos spooled and carried through all the way to the limiter where it bounced a couple of times before going kaput. Whole thing must have lasted like 3 seconds FWIW...

Did you use a new crank hub, grip disk and bolt or reuse your old ones ?

Negative, you only need to change hub and grip disc in case you have a failure , bolt is 1-time use, torqued to 100Nm + 360-deg as per factory spec

 

[martymil]

As far as I was told by BMW Australia the hub, bolt and grip disk is all one time use and for a measly 100 dollars max why not change it but anything to do with timing I got new even a new timing chain when the old ones was only 20k old that's just me I suppose.

Prevention is cheaper than cure.

 

[Optigrab]

New crank hub solution is out

 

[martymil]

awesome news, got a few customers needing these.

 

[MoreBoost]

Mine slipped with bolt ons and inlets on pump fuel

i meant to ask, what transmission?

Do you recall when it happened?

Harsh shifts or did it just happen gradually?

There's an M3 here where it just throws codes. Doesn't look that harshly driven.

 

[MoreBoost]

so what are people's thoughts on the vtt option vs the maximum psi option, despite it being cheaper?

https://bmw.spoolstreet.com/threads/maximum-psi-keyed-crank-hub.3145/

 

[Rob09msport]

It's one of those why didn't I think of that things def a winner . Even if wasn't cheaper seems like a more elegant solution.