European Auto Source (EAS)
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read

Go Back   BMW M3 and BMW M4 Forum > BMW F80 M3 / F82 M4 Technical Topics > Engine / Drivetrain / Exhaust / Bolt-ons / Tuning

Post Reply
 
Thread Tools Search this Thread
      04-15-2019, 03:06 PM   #67
Smee
Colonel
Smee's Avatar
475
Rep
2,152
Posts

Drives: BMW M4 F83
Join Date: Aug 2016
Location: Norfolk

iTrader: (0)

can anyone explain to me how this CBC stops the bolt from unwinding?

not a trick question i am looking to purchase one but before i pulled the trigger something in my mind pinged and said no.
__________________
Current: BMW M4 F83 - Mods : Pedal Covers, LCI Stereo facia Retrofit and Carbon Rear corner covers

Old: F32 435d M Sport - Mods : HR Sport Springs, 20" Veemann V-FS23 in Gun Metal, M Performance Body Kit, Pedal Covers, Eurspec CF Mirror Caps, More-BHP remap 364 BHP 741 NM, M4 Under Chassis Brace, 15mm Rear ARB, 8.8" Screen Retrofit and LCI Stereo facia Retrofit
Appreciate 0
      04-15-2019, 05:53 PM   #68
Rotzy
Captain
Rotzy's Avatar
United_States
486
Rep
647
Posts

Drives: 2016 F15, 2015 F83
Join Date: May 2014
Location: RI

iTrader: (0)

Garage List
Quote:
Originally Posted by Smee View Post
can anyone explain to me how this CBC stops the bolt from unwinding?

not a trick question i am looking to purchase one but before i pulled the trigger something in my mind pinged and said no.
The crank bolt and the hub are two separate pieces. The bolt runs through the center of the hub and is heavily torqued. The faceplate of the hub has 8 threaded bolt holes that the crank pulley is mounted to. In addition, the head of the crank bolt protrudes approximately 3/4" - 1" past the face of the hub.

The Crank Bolt Capture encapsulates the head of the crank bolt and is secured to the faceplate of the pulley/hub using the 8 aforementioned bolt locations. This prevents the crank bolt from rotating independent of the hub (ie. backing out) but does not prevent a failure of the friction disks or possible stretching of the crank bolt. That is why it is only a partial solution.
__________________
2016 F15 X5 50i M-Sport
2015 F83 M4
Appreciate 0
      04-15-2019, 06:03 PM   #69
Smee
Colonel
Smee's Avatar
475
Rep
2,152
Posts

Drives: BMW M4 F83
Join Date: Aug 2016
Location: Norfolk

iTrader: (0)

Quote:
Originally Posted by Rotzy View Post
Quote:
Originally Posted by Smee View Post
can anyone explain to me how this CBC stops the bolt from unwinding?

not a trick question i am looking to purchase one but before i pulled the trigger something in my mind pinged and said no.
The crank bolt and the hub are two separate pieces. The bolt runs through the center of the hub and is heavily torqued. The faceplate of the hub has 8 threaded bolt holes that the crank pulley is mounted to. In addition, the head of the crank bolt protrudes approximately 3/4" - 1" past the face of the hub.

The Crank Bolt Capture encapsulates the head of the crank bolt and is secured to the faceplate of the pulley/hub using the 8 aforementioned bolt locations. This prevents the crank bolt from rotating independent of the hub (ie. backing out) but does not prevent a failure of the friction disks or possible stretching of the crank bolt. That is why it is only a partial solution.
Ok so the bolt can still back out of the crank but now instead of just the bolt backing out the hub and pulley would go with it?
__________________
Current: BMW M4 F83 - Mods : Pedal Covers, LCI Stereo facia Retrofit and Carbon Rear corner covers

Old: F32 435d M Sport - Mods : HR Sport Springs, 20" Veemann V-FS23 in Gun Metal, M Performance Body Kit, Pedal Covers, Eurspec CF Mirror Caps, More-BHP remap 364 BHP 741 NM, M4 Under Chassis Brace, 15mm Rear ARB, 8.8" Screen Retrofit and LCI Stereo facia Retrofit
Appreciate 0
      04-15-2019, 06:33 PM   #70
MR RIZK
Major
MR RIZK's Avatar
Australia
504
Rep
1,046
Posts

Drives: AW M2C
Join Date: Mar 2013
Location: Australia

iTrader: (0)

@smee I think you need to look at the etk to see how it goes together as this should clear it up for you along with @rotzy description.

http://www.realoem.com/bmw/enUS/show...diagId=11_5597
__________________
Previous Rides: 13' 135i, 08' 130i, 03' HKS Turbo'd 350z, Modded GC8 WRX, NA MX5
Appreciate 0
      04-15-2019, 06:38 PM   #71
Rotzy
Captain
Rotzy's Avatar
United_States
486
Rep
647
Posts

Drives: 2016 F15, 2015 F83
Join Date: May 2014
Location: RI

iTrader: (0)

Garage List
Quote:
Originally Posted by Smee View Post
Ok so the bolt can still back out of the crank but now instead of just the bolt backing out the hub and pulley would go with it?
In a way, yes, but the only way the hub and pulley are coming out with the CBC installed is if you spin your crank hub (ie. the friction disks fail/crack or the bolt stretches reducing the clamping torque on the assembly.) In that case, the hub was going to spin with or without the CBC.

Remember, the bolt and hub normally spin as one clamped assembly. It's only when something fails (or the bolt backs out) that they shift (ie. momentarily spin independently), thus throwing off the timing.
__________________
2016 F15 X5 50i M-Sport
2015 F83 M4
Appreciate 0
      04-16-2019, 03:02 AM   #72
Smee
Colonel
Smee's Avatar
475
Rep
2,152
Posts

Drives: BMW M4 F83
Join Date: Aug 2016
Location: Norfolk

iTrader: (0)

many thanks. you 2 are a lot better at explaining than some others

so one more question does the hub get pressure fitted in to the hole in the end of the crank?

i.e if you took the bolt out does the hub simple fall off or do you need a to whack it off or pull it off with an extractor?
__________________
Current: BMW M4 F83 - Mods : Pedal Covers, LCI Stereo facia Retrofit and Carbon Rear corner covers

Old: F32 435d M Sport - Mods : HR Sport Springs, 20" Veemann V-FS23 in Gun Metal, M Performance Body Kit, Pedal Covers, Eurspec CF Mirror Caps, More-BHP remap 364 BHP 741 NM, M4 Under Chassis Brace, 15mm Rear ARB, 8.8" Screen Retrofit and LCI Stereo facia Retrofit
Appreciate 0
      04-16-2019, 03:44 AM   #73
MR RIZK
Major
MR RIZK's Avatar
Australia
504
Rep
1,046
Posts

Drives: AW M2C
Join Date: Mar 2013
Location: Australia

iTrader: (0)

I can only assume as have not performed this myself but based on what I have read and the TIS it is a snug fit not a pressure fit. The TIS says just pull it out by hand with two of the damper bolts reattached to get grip.
__________________
Previous Rides: 13' 135i, 08' 130i, 03' HKS Turbo'd 350z, Modded GC8 WRX, NA MX5
Appreciate 0
      04-16-2019, 09:56 AM   #74
ssgm1x
Lieutenant
ssgm1x's Avatar
United_States
227
Rep
574
Posts

Drives: 2018 BMW M3
Join Date: Aug 2017
Location: cherry hill ,NJ

iTrader: (0)

Quote:
Originally Posted by Smee View Post
Quote:
Originally Posted by Rotzy View Post
Quote:
Originally Posted by Smee View Post
can anyone explain to me how this CBC stops the bolt from unwinding?

not a trick question i am looking to purchase one but before i pulled the trigger something in my mind pinged and said no.
The crank bolt and the hub are two separate pieces. The bolt runs through the center of the hub and is heavily torqued. The faceplate of the hub has 8 threaded bolt holes that the crank pulley is mounted to. In addition, the head of the crank bolt protrudes approximately 3/4" - 1" past the face of the hub.

The Crank Bolt Capture encapsulates the head of the crank bolt and is secured to the faceplate of the pulley/hub using the 8 aforementioned bolt locations. This prevents the crank bolt from rotating independent of the hub (ie. backing out) but does not prevent a failure of the friction disks or possible stretching of the crank bolt. That is why it is only a partial solution.
Ok so the bolt can still back out of the crank but now instead of just the bolt backing out the hub and pulley would go with it?
I believe the majority of Spun Hubs occur when the Crank Bolt comes loose. The Capture just prevents the bolt from coming loose, reducing the odds of a Spun hub.
The Capture costs about $450 installed (part included)
__________________
2018 BMW M3 DCT
10.67sec 1/4mi.@ 133.7mph, Dragy 6.6sec. 60-130, Stock Turbos, F80 Paul, BM3
Appreciate 0
      04-18-2019, 01:39 AM   #75
FreeDarko
Lieutenant
175
Rep
578
Posts

Drives: F80
Join Date: Mar 2018
Location: UpNorth

iTrader: (0)

Quote:
Originally Posted by ssgm1x View Post
I believe the majority of Spun Hubs occur when the Crank Bolt comes loose. The Capture just prevents the bolt from coming loose, reducing the odds of a Spun hub.
The Capture costs about $450 installed (part included)
But has there been a case on this forum atleast where the CBC was installed and something related to crank hub failed.
Appreciate 0
      04-18-2019, 02:48 AM   #76
Smee
Colonel
Smee's Avatar
475
Rep
2,152
Posts

Drives: BMW M4 F83
Join Date: Aug 2016
Location: Norfolk

iTrader: (0)

Quote:
Originally Posted by FreeDarko View Post
But has there been a case on this forum atleast where the CBC was installed and something related to crank hub failed.
Can you get the link please cos I hadn't seen one. Didn't think there was any evidence of a failure with just a capture
Appreciate 0
      04-18-2019, 05:18 AM   #77
MR RIZK
Major
MR RIZK's Avatar
Australia
504
Rep
1,046
Posts

Drives: AW M2C
Join Date: Mar 2013
Location: Australia

iTrader: (0)

Quote:
Originally Posted by Smee View Post
Quote:
Originally Posted by FreeDarko View Post
But has there been a case on this forum atleast where the CBC was installed and something related to crank hub failed.
Can you get the link please cos I hadn't seen one. Didn't think there was any evidence of a failure with just a capture
I think u are mis reading the post and swapping the words "has and there" around. I believe the poster is asking if there are any failures recorded with the CBC installed. Ie the same answer u are chasing.
__________________
Previous Rides: 13' 135i, 08' 130i, 03' HKS Turbo'd 350z, Modded GC8 WRX, NA MX5
Appreciate 0
      04-18-2019, 05:19 AM   #78
FreeDarko
Lieutenant
175
Rep
578
Posts

Drives: F80
Join Date: Mar 2018
Location: UpNorth

iTrader: (0)

Quote:
Originally Posted by Smee View Post
Can you get the link please cos I hadn't seen one. Didn't think there was any evidence of a failure with just a capture
Sorry that was a question.
Appreciate 0
      04-18-2019, 06:36 AM   #79
Smee
Colonel
Smee's Avatar
475
Rep
2,152
Posts

Drives: BMW M4 F83
Join Date: Aug 2016
Location: Norfolk

iTrader: (0)

Quote:
Originally Posted by FreeDarko View Post
Quote:
Originally Posted by Smee View Post
Can you get the link please cos I hadn't seen one. Didn't think there was any evidence of a failure with just a capture
Sorry that was a question.
was early in the morning lol sorry
__________________
Current: BMW M4 F83 - Mods : Pedal Covers, LCI Stereo facia Retrofit and Carbon Rear corner covers

Old: F32 435d M Sport - Mods : HR Sport Springs, 20" Veemann V-FS23 in Gun Metal, M Performance Body Kit, Pedal Covers, Eurspec CF Mirror Caps, More-BHP remap 364 BHP 741 NM, M4 Under Chassis Brace, 15mm Rear ARB, 8.8" Screen Retrofit and LCI Stereo facia Retrofit
Appreciate 0
      04-18-2019, 12:32 PM   #80
Rotzy
Captain
Rotzy's Avatar
United_States
486
Rep
647
Posts

Drives: 2016 F15, 2015 F83
Join Date: May 2014
Location: RI

iTrader: (0)

Garage List
Quote:
Originally Posted by FreeDarko View Post
But has there been a case on this forum atleast where the CBC was installed and something related to crank hub failed.
Nothing that I’ve seen yet, and that gives me hope, but that doesn’t mean we’re 100% safe with just the CBC.

There is at least one user who had 2 SCHs before installing the CBC and has been good since.

There is also another user that posted not too long ago who was doing a preemptive crank hub upgrade. The shop found a deformed and broken friction disk during disassembly. His hub was a ticking time bomb that would not have been saved with a CBC.
__________________
2016 F15 X5 50i M-Sport
2015 F83 M4
Appreciate 0
      07-20-2019, 03:01 PM   #81
Beemerm3
First Lieutenant
Beemerm3's Avatar
54
Rep
333
Posts

Drives: 16' BMW m3
Join Date: Jul 2019
Location: Sacramento

iTrader: (0)

I just got my cbc installed at svbimmer. Haven't drove the car since then. Stock zcp. Out of warranty.
Appreciate 0
      07-22-2019, 02:32 AM   #82
tanzm4_
Second Lieutenant
tanzm4_'s Avatar
United_States
150
Rep
238
Posts

Drives: '18 M4 ZCP - Tanzanite Blue
Join Date: Feb 2019
Location: Bay Area, CA

iTrader: (0)

How much did they charge you guys (sv bimmer)
Appreciate 0
      10-17-2019, 09:06 PM   #83
Beemerm3
First Lieutenant
Beemerm3's Avatar
54
Rep
333
Posts

Drives: 16' BMW m3
Join Date: Jul 2019
Location: Sacramento

iTrader: (0)

About 600$ forgot. I had to get an alignment too. Which was expensive lol.
Appreciate 0
      12-27-2019, 09:16 PM   #84
techlogik
Lieutenant Colonel
60
Rep
1,549
Posts

Drives: 2011 335is Coupe
Join Date: Dec 2006
Location: FL

iTrader: (2)

Quote:
Originally Posted by Bmwlmr99 View Post
They run these cars hard for an hour or more , some 24hr events....downshifting and upshifts constantly...no issues with sch
Yes, and they can just put another engine sitting in the crate in the garage in after each race if they want. Or did they say they run the same engine forever and the entire season?
Appreciate 0
      12-27-2019, 09:32 PM   #85
techlogik
Lieutenant Colonel
60
Rep
1,549
Posts

Drives: 2011 335is Coupe
Join Date: Dec 2006
Location: FL

iTrader: (2)

The problem with the spline setup IMHO is the spline is supposed to "tighten" and hold better if the crank and gears experience spin. If that is the case, then the timing will then be off as it tightens. There is micro slippage and movement. Thought that was their design explanation instead of a key?

Many engine builders will suggest keyed shaft setups. Better than what BMW did for whatever stupid reason. Engineers should be fired for that dumb idea.

But still, that works sort of like a shear pin. It can shear and fail. Just ups the limit it takes to do it. Better idea when running ok mods and higher power. Some insurance there. But 4k for that and hours? Ouch.

I think the inexpensive plate with reasonable boost stage 1 this is a good reasonable solution. If you are going to run Stage 2 and up and drag racing, launching with DCT, then you should reinforce with something better than the plate. But wow, again, the cost for something that shouldn't have been an issue to begin with is hard to swallow and understand.

So either be prepared for the worse case and have $$$, or just move on to another car....sad.
Appreciate 0
      12-28-2019, 01:21 AM   #86
Beemerm3
First Lieutenant
Beemerm3's Avatar
54
Rep
333
Posts

Drives: 16' BMW m3
Join Date: Jul 2019
Location: Sacramento

iTrader: (0)

My car is going to have 200k miles mpe exhaust. Bm3 stage 1 tune. Only cbc. Ftw. Lol
Appreciate 2
      12-28-2019, 11:56 AM   #87
Chris@VargasTurboTech
BimmerPost Supporting Vendor
1599
Rep
1,443
Posts


Drives: All Things TurboCharged
Join Date: May 2016
Location: Bay Area

iTrader: (0)

Quote:
Originally Posted by techlogik View Post
The problem with the spline setup IMHO is the spline is supposed to "tighten" and hold better if the crank and gears experience spin. If that is the case, then the timing will then be off as it tightens. There is micro slippage and movement. Thought that was their design explanation instead of a key?

Many engine builders will suggest keyed shaft setups. Better than what BMW did for whatever stupid reason. Engineers should be fired for that dumb idea.

But still, that works sort of like a shear pin. It can shear and fail. Just ups the limit it takes to do it. Better idea when running ok mods and higher power. Some insurance there. But 4k for that and hours? Ouch.

I think the inexpensive plate with reasonable boost stage 1 this is a good reasonable solution. If you are going to run Stage 2 and up and drag racing, launching with DCT, then you should reinforce with something better than the plate. But wow, again, the cost for something that shouldn't have been an issue to begin with is hard to swallow and understand.

So either be prepared for the worse case and have $$$, or just move on to another car....sad.
Spline lock V2 is straight cut splines, pressed in. Zero reported failures or slip, it's far more aggressive than the original spline lock.

https://f80.bimmerpost.com/forums/sh....php?t=1621073

Chris
Appreciate 0
      12-28-2019, 12:13 PM   #88
ASRman
Private First Class
89
Rep
127
Posts

Drives: F80 M3 competition 2018
Join Date: May 2019
Location: United States

iTrader: (0)

VTT said V1 wouldn't slip. And took people's money on the basis it was a crank hub fix. Plenty of V1s have now slipped. Why should anyone trust that V2 will be any different. Gintani or Max PSI all the way.
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 11:00 PM.




f80post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST