Autotalent
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

View Poll Results: Ultimate S55 Spun Crank Hub Poll -- Please vote
2014-2015 | 6MT | Stock | No SCH 64 6.21%
2014-2015 | 6MT | Stock | SCH Failure 3 0.29%
2014-2015 | 6MT | Modified 450-500 whp | No SCH 28 2.72%
2014-2015 | 6MT | Modified 450-500 whp | SCH Failure 6 0.58%
2014-2015 | 6MT | Modified 500-550 whp | No SCH 15 1.46%
2014-2015 | 6MT | Modified 500-550 whp | SCH Failure 4 0.39%
2014-2015 | 6MT | Modified 550+ whp | No SCH 8 0.78%
2014-2015 | 6MT | Modified 550+ whp | SCH Failure 5 0.49%
2014-2015 | DCT | Stock | No SCH 114 11.07%
2014-2015 | DCT | Stock | SCH Failure 2 0.19%
2014-2015 | DCT | Modified 450-500 whp | No SCH 65 6.31%
2014-2015 | DCT | Modified 450-500 whp | SCH Failure 5 0.49%
2014-2015 | DCT | Modified 500-550 whp | No SCH 32 3.11%
2014-2015 | DCT | Modified 500-550 whp | SCH Failure 4 0.39%
2014-2015 | DCT | Modified 550+ whp | No SCH 19 1.84%
2014-2015 | DCT | Modified 550+ whp | SCH Failure 7 0.68%
2016 | 6MT | Stock | No SCH 45 4.37%
2016 | 6MT | Stock | SCH Failure 3 0.29%
2016 | 6MT | Modified 450-500 whp | No SCH 17 1.65%
2016 | 6MT | Modified 450-500 whp | SCH Failure 2 0.19%
2016 | 6MT | Modified 500-550 whp | No SCH 9 0.87%
2016 | 6MT | Modified 500-550 whp | SCH Failure 3 0.29%
2016 | 6MT | Modified 550+ whp | No SCH 2 0.19%
2016 | 6MT | Modified 550+ whp | SCH Failure 1 0.10%
2016 | 6MT Comp Package | Stock | No SCH 8 0.78%
2016 | 6MT Comp Package | Stock | SCH Failure 1 0.10%
2016 | 6MT Comp Package | Modified 450-500 whp | No SCH 0 0%
2016 | 6MT Comp Package | Modified 450-500 whp | SCH Failure 2 0.19%
2016 | 6MT Comp Package | Modified 500-550 whp | No SCH 2 0.19%
2016 | 6MT Comp Package | Modified 500-550 whp | SCH Failure 0 0%
2016 | 6MT Comp Package | Modified 550+ whp | No SCH 0 0%
2016 | 6MT Comp Package | Modified 550+ whp | SCH Failure 0 0%
2016 | DCT | Stock | No SCH 78 7.57%
2016 | DCT | Stock | SCH Failure 0 0%
2016 | DCT | Modified 450-500 whp | No SCH 36 3.50%
2016 | DCT | Modified 450-500 whp | SCH Failure 2 0.19%
2016 | DCT | Modified 500-550 whp | No SCH 19 1.84%
2016 | DCT | Modified 500-550 whp | SCH Failure 0 0%
2016 | DCT | Modified 550+ whp | No SCH 5 0.49%
2016 | DCT | Modified 550+ whp | SCH Failure 3 0.29%
2016 | DCT Comp Package | Stock | No SCH 14 1.36%
2016 | DCT Comp Package | Stock | SCH Failure 0 0%
2016 | DCT Comp Package | Modified 450-500 whp | No SCH 2 0.19%
2016 | DCT Comp Package | Modified 450-500 whp | SCH Failure 0 0%
2016 | DCT Comp Package | Modified 500-550 whp | No SCH 4 0.39%
2016 | DCT Comp Package | Modified 500-550 whp | SCH Failure 3 0.29%
2016 | DCT Comp Package | Modified 550+ whp | No SCH 3 0.29%
2016 | DCT Comp Package | Modified 550+ whp | SCH Failure 2 0.19%
2017 | 6MT | Stock | No SCH 11 1.07%
2017 | 6MT | Stock | SCH Failure 0 0%
2017 | 6MT | Modified 450-500 whp | No SCH 2 0.19%
2017 | 6MT | Modified 450-500 whp | SCH Failure 1 0.10%
2017 | 6MT | Modified 500-550 whp | No SCH 2 0.19%
2017 | 6MT | Modified 500-550 whp | SCH Failure 0 0%
2017 | 6MT | Modified 550+ whp | No SCH 1 0.10%
2017 | 6MT | Modified 550+ whp | SCH Failure 0 0%
2017 | 6MT Comp Package | Stock | No SCH 17 1.65%
2017 | 6MT Comp Package | Stock | SCH Failure 1 0.10%
2017 | 6MT Comp Package | Modified 450-500 whp | No SCH 3 0.29%
2017 | 6MT Comp Package | Modified 450-500 whp | SCH Failure 1 0.10%
2017 | 6MT Comp Package | Modified 500-550 whp | No SCH 2 0.19%
2017 | 6MT Comp Package | Modified 500-550 whp | SCH Failure 1 0.10%
2017 | 6MT Comp Package | Modified 550+ whp | No SCH 2 0.19%
2017 | 6MT Comp Package | Modified 550+ whp | SCH Failure 0 0%
2017 | DCT | Stock | No SCH 27 2.62%
2017 | DCT | Stock | SCH Failure 0 0%
2017 | DCT | Modified 450-500 whp | No SCH 4 0.39%
2017 | DCT | Modified 450-500 whp | SCH Failure 2 0.19%
2017 | DCT | Modified 500-550 whp | No SCH 7 0.68%
2017 | DCT | Modified 500-550 whp | SCH Failure 2 0.19%
2017 | DCT | Modified 550+ whp | No SCH 3 0.29%
2017 | DCT | Modified 550+ whp | SCH Failure 2 0.19%
2017 | DCT Comp Package | Stock | No SCH 33 3.20%
2017 | DCT Comp Package | Stock | SCH Failure 1 0.10%
2017 | DCT Comp Package | Modified 450-500 whp | No SCH 12 1.17%
2017 | DCT Comp Package | Modified 450-500 whp | SCH Failure 0 0%
2017 | DCT Comp Package | Modified 500-550 whp | No SCH 9 0.87%
2017 | DCT Comp Package | Modified 500-550 whp | SCH Failure 0 0%
2017 | DCT Comp Package | Modified 550+ whp | No SCH 5 0.49%
2017 | DCT Comp Package | Modified 550+ whp | SCH Failure 1 0.10%
2018+ | 6MT | Stock | No SCH 33 3.20%
2018+ | 6MT | Stock | SCH Failure 1 0.10%
2018+ | 6MT | Modified 450-500 whp | No SCH 5 0.49%
2018+ | 6MT | Modified 450-500 whp | SCH Failure 1 0.10%
2018+ | 6MT | Modified 500-550 whp | No SCH 1 0.10%
2018+ | 6MT | Modified 500-550 whp | SCH Failure 4 0.39%
2018+ | 6MT | Modified 550+ whp | No SCH 0 0%
2018+ | 6MT | Modified 550+ whp | SCH Failure 0 0%
2018+ | 6MT Comp Package | Stock | No SCH 38 3.69%
2018+ | 6MT Comp Package | Stock | SCH Failure 1 0.10%
2018+ | 6MT Comp Package | Modified 450-500 whp | No SCH 9 0.87%
2018+ | 6MT Comp Package | Modified 450-500 whp | SCH Failure 2 0.19%
2018+ | 6MT Comp Package | Modified 500-550 whp | No SCH 5 0.49%
2018+ | 6MT Comp Package | Modified 500-550 whp | SCH Failure 0 0%
2018+ | 6MT Comp Package | Modified 550+ whp | No SCH 3 0.29%
2018+ | 6MT Comp Package | Modified 550+ whp | SCH Failure 0 0%
2018+ | DCT | Stock | No SCH 30 2.91%
2018+ | DCT | Stock | SCH Failure 3 0.29%
2018+ | DCT | Modified 450-500 whp | No SCH 7 0.68%
2018+ | DCT | Modified 450-500 whp | SCH Failure) 2 0.19%
2018+ | DCT | Modified 500-550 whp | No SCH 4 0.39%
2018+ | DCT | Modified 500-550 whp | SCH Failure 3 0.29%
2018+ | DCT | Modified 550+ whp | No SCH 2 0.19%
2018+ | DCT | Modified 550+ whp | SCH Failure 2 0.19%
2018+ | DCT Comp Package | Stock | No SCH 52 5.05%
2018+ | DCT Comp Package | Stock | SCH Failure 3 0.29%
2018+ | DCT Comp Package | Modified 450-500 whp | No SCH 12 1.17%
2018+ | DCT Comp Package | Modified 450-500 whp | SCH Failure) 4 0.39%
2018+ | DCT Comp Package | Modified 500-550 whp | No SCH 12 1.17%
2018+ | DCT Comp Package | Modified 500-550 whp | SCH Failure 4 0.39%
2018+ | DCT Comp Package | Modified 550+ whp | No SCH 9 0.87%
2018+ | DCT Comp Package | Modified 550+ whp | SCH Failure 8 0.78%
Multiple Choice Poll. Voters: 1030. You may not vote on this poll

Post Reply
 
Thread Tools Search this Thread
      10-22-2020, 06:07 AM   #243
CT_M3
Private First Class
203
Rep
158
Posts

Drives: F80 M3 DCT Competition
Join Date: Jul 2010
Location: Bay Area, CA

iTrader: (0)

Did a quick statistical breakdown of the poll as it stands a few nights ago but posted it in another thread. Adding it here to share with everyone who is concerned about this.

“I took the poll that was done a while back and just did simple statistics to see what the fail rate was:

I was going to play with the numbers a little more but that's ok, I'm open to sharing this with anyone who reads it.

Because of the smaller sample size of tuned cars, I didn't split between DCT/Manual or year to get a general sense of the weight of the numbers.

Stock: 3% failure rate (out of 555 cars)
450-500whp tune: 11% (out of 227 cars)
500-550whp tunes: 19% (out of 149 cars)
550+ whp tunes: 33% (out of 90 cars)

If you focus on just manual vs. dct (tuned cars only),
Manual: 22% fail rate (out of 146 cars)
DCT: 18% fail rate (out of 320 cars)

Takeaway: if you do a light tune, you'd be silly not put on a CBC, or as Clint would say "You feeling lucky today?"

Assuming the cost of a motor is 15-20K, if you're going to light tune, you need at the minimum, a budget of $1- 1.5k (based on the general probability of failure, so a CBC is probably a good way to go about it.

papasmurf_m3 had some good points. If you follow folks like Apex Ring Taxi, they haven’t had SCH failures on their M4 ring taxis and were wondering why it was happening to M3/M4 owners. It’s clearly driving behavior. That has a sizeable component to it.

So: Don’t floor it when you are in high gear and low rpm and I would add, stay in S2, until you put a fix in. The Ring guys are almost always in middle to high gears with high rpm all day long.
Appreciate 0
      10-22-2020, 12:06 PM   #244
cheveux
Private First Class
199
Rep
123
Posts

Drives: 2014 M4
Join Date: May 2018
Location: Portugal

iTrader: (0)

Quote:
Originally Posted by CT_M3 View Post
Did a quick statistical breakdown of the poll as it stands a few nights ago but posted it in another thread. Adding it here to share with everyone who is concerned about this.

ďI took the poll that was done a while back and just did simple statistics to see what the fail rate was:

I was going to play with the numbers a little more but that's ok, I'm open to sharing this with anyone who reads it.

Because of the smaller sample size of tuned cars, I didn't split between DCT/Manual or year to get a general sense of the weight of the numbers.

Stock: 3% failure rate (out of 555 cars)
450-500whp tune: 11% (out of 227 cars)
500-550whp tunes: 19% (out of 149 cars)
550+ whp tunes: 33% (out of 90 cars)

If you focus on just manual vs. dct (tuned cars only),
Manual: 22% fail rate (out of 146 cars)
DCT: 18% fail rate (out of 320 cars)

Takeaway: if you do a light tune, you'd be silly not put on a CBC, or as Clint would say "You feeling lucky today?"

Assuming the cost of a motor is 15-20K, if you're going to light tune, you need at the minimum, a budget of $1- 1.5k (based on the general probability of failure, so a CBC is probably a good way to go about it.

papasmurf_m3 had some good points. If you follow folks like Apex Ring Taxi, they havenít had SCH failures on their M4 ring taxis and were wondering why it was happening to M3/M4 owners. Itís clearly driving behavior. That has a sizeable component to it.

So: Donít floor it when you are in high gear and low rpm and I would add, stay in S2, until you put a fix in. The Ring guys are almost always in middle to high gears with high rpm all day long.

The M4 from Apex is stock but has cbc from Burkhart engineering
Appreciate 0
      10-22-2020, 12:19 PM   #245
CT_M3
Private First Class
203
Rep
158
Posts

Drives: F80 M3 DCT Competition
Join Date: Jul 2010
Location: Bay Area, CA

iTrader: (0)

Quote:
Originally Posted by cheveux View Post
The M4 from Apex is stock but has cbc from Burkhart engineering
Really? That's a good data point. Robert Mitchell didn't mention it in a recent video on Misha's channel.

Here's what he said:

A viewer commented:
After watching the video, I still have a question, I don't know if it will get answered. I know this S55 engines have the crank hub issue, and when I watch Misha's videos and see the M3 and M4 I always wonder how this cars can keep up with all the laps without having a failure on the crank hub. Most of the M3s and M4s are usually used in the street with some track use along their life, but not always in track. I know that the crank hub issue normally happens to cars that are tuned, but also on stock cars. Any info about this?

Robert Mitchell
I can say that w all of our S55 cars we have had no hub issue... so its sort of a mystery to me that everyone is doin this ''fix'' and we've not seen the other end of what needs to be fixed lol
Appreciate 0
      10-22-2020, 05:40 PM   #246
cheveux
Private First Class
199
Rep
123
Posts

Drives: 2014 M4
Join Date: May 2018
Location: Portugal

iTrader: (0)

Quote:
Originally Posted by CT_M3 View Post
Really? That's a good data point. Robert Mitchell didn't mention it in a recent video on Misha's channel.

Here's what he said:

A viewer commented:
After watching the video, I still have a question, I don't know if it will get answered. I know this S55 engines have the crank hub issue, and when I watch Misha's videos and see the M3 and M4 I always wonder how this cars can keep up with all the laps without having a failure on the crank hub. Most of the M3s and M4s are usually used in the street with some track use along their life, but not always in track. I know that the crank hub issue normally happens to cars that are tuned, but also on stock cars. Any info about this?

Robert Mitchell
I can say that w all of our S55 cars we have had no hub issue... so its sort of a mystery to me that everyone is doin this ''fix'' and we've not seen the other end of what needs to be fixed lol
In the end of 2019 i asked misha if his m3 and m4 were tuned or had some crank hub fix. he said they were stock but that the mechanic could help me with the other information. the mechanic is @that_nurburgring_guy on Instagram. He told me that he installs the burkhart kit to have peace of mind. It only happened twice in his workshop.

Appreciate 0
      10-22-2020, 06:27 PM   #247
CT_M3
Private First Class
203
Rep
158
Posts

Drives: F80 M3 DCT Competition
Join Date: Jul 2010
Location: Bay Area, CA

iTrader: (0)

Thanks for this nugget of information! Is that similar to a CBC solution or was it a keyed/pinned solution?
Appreciate 0
      10-23-2020, 06:06 AM   #248
cheveux
Private First Class
199
Rep
123
Posts

Drives: 2014 M4
Join Date: May 2018
Location: Portugal

iTrader: (0)

Quote:
Originally Posted by CT_M3 View Post
Thanks for this nugget of information! Is that similar to a CBC solution or was it a keyed/pinned solution?
It's a cbc. you can see it in my thread: https://f80.bimmerpost.com/forums/sh....php?t=1693978

I personally continue to say that the sch has a lot to do with 50% driving habits and 50% torque
Appreciate 1
CT_M3203.00

      10-23-2020, 09:12 AM   #249
Electric
Private
United_States
18
Rep
98
Posts

Drives: 2016 BMW M3 Competition
Join Date: Oct 2007
Location: NJ

iTrader: (0)

Quote:
Originally Posted by papasmurf_m3 View Post
I've been following the spread of misinformation and fear mongering. So, I will weigh in my thoughts as a person who has built racing engines, tuned cars on my dyno, raced on a competitive level, & built many fast cars when I owned a shop. (BTW It was fun. But, I don't miss the shop life)

Take this with a grain of salt. It's just 1 guys opinion that is based on factual information, first and second hand experience, talking with my buddies who are E85 tuned stock hubs, talking with people who slipped. etc... But, you all know what they say about opinions.

Is this crank hub thing real? Yes, It is. But, that does not mean every car is a ticking time bomb. No, not even close to it. It comes down to how you are driving the car. Nobody has answers and people think it's this or that. Or the year or manual or dct. So let me explain.

I believe this is due to 2 simple things. High torque and low rpm. When you have massive torque at 2000 rpm that is what causes the bolt to back out and that loss of torque on the hub will allow the timing chain sprocket to slip. And it's a slip not spinning freely 360 degrees. It's ok to have high torque at higher rpm because the engine is spinning faster. But, not so much at low rpm. It's fun though. But, no bueno for that bolt from backing out.

Think about it logically for a moment. The timing sprocket is under load with heavy boost and cylinder pressures. Do you think the cylinder pressures are enough to hulka-maniac it's way through a fully torqued factory crank bolt? Like raaaawr & just take out your entire motor, just like that.... Really? I can see if the bolt backs out and you lose torque. But, not if it's fully torqued. Get outta here with that.


If you are tuned or even w/ high torque of the E85 and running stock crank hub. Just do these things to avoid an issue:

No burnouts, no doughnuts, no kickdowns, no launching, no downshift UNDER high torque. Lift of the gas and downshift all you want. Don't rip the car at low engine speeds and high torque. Get on it from a 50 roll 60 roll all day long. Have fun with rolls and higher speeds all day. Just be mindful.

If you wanna send it, If you are going 600 700 800 whp and a lot of torque, wanna do burnouts etc then just do a crank hub fix. They are all really good. They all do the same thing. It's the labor cost that will kill your wallet. That VTT V2 looks like a good option though. Because, it installs so easily. Much easier then the 2 or 4 pin. If they all do the same. Then my logic says. Go with the path of least resistance. Lighter on the wallet and simpler installation makes the most sense. 2 pin 4 pin are great too. Just a lot more work and messy. They work just fine too. It's your preference.

If you're stock, just send it! You're fine. Your motor is not going to blow up at any second. Get outta here with that too. But, I would be mindful.

Valves don't bend because of pistons hitting them. They bend from intake valve colliding with them. Then when bent enough the pistons comes up and snaps it off eventually. But, that can only really happen from very bad valve float and under extreme conditions.

I've seen some shops crank the bolt over and over when the car comes in with slipped hub. Why?? That is causing more damage. I would not do that. If the car is out of time. Don't do that. Just fix it.

For context. My car is stock. I'm just waiting for my parts to arrive. Probably stage 2 Ecutek e85 max effort tune to start things off. I drive the car and enjoy it. I have launched it before. Yes, I take it to canyons and backroads and really put this car through its paces as an all around sports sedan. The car see's a lot of 40 & 60 rolling start races. I have burned out a few times. As of lately I follow my guideline to the T.

I plan to run crank hub fix. Only because, I plan to send it with bigger turbos. So, i will do them at the same time. Most likely it will stay on stock turbos and follow the guidelines till then.

I'm going with the VTT V2 crank hub fix for it's quality. It works perfectly under high stress, easy to install and the most cost effective. No brainer.

I'm not ripping on any shops or companies. I'm just an enthusiast and just sick of every other post about the same thing. All this fear mongering and people genuinely getting stressed about their cars. That sucks & I think it's blown out of proportion.

If you're going to send it. Just put one on. Any of them. it doesn't matter. They all do the same thing.


(Was trying to edit some grammar and I accidentally deleted some stuff. I don't remember right now lol But, ya. This is the gist of it.)

Just my 2 cents guys.

Cheers,

Max-
Can you elaborate what a "downshift UNDER high torque" is?

I am really torn between getting a CBC or full fix. I am at good power (no E85 though), 6MT, and I don't do burnouts, floor it at low RPM, etc. But still conerned!
__________________
2016 F80 ZCP 6MT - Yas Marina Blue
529rwhp/549tq - BM3 OTS2 (OEM exhaust)
Appreciate 0
      10-23-2020, 08:32 PM   #250
papasmurf_m3
Lieutenant
papasmurf_m3's Avatar
United_States
235
Rep
577
Posts

Drives: YMB F80 M3
Join Date: Apr 2019
Location: San Diego

iTrader: (0)

Quote:
Originally Posted by Electric View Post
Quote:
Originally Posted by papasmurf_m3 View Post
I've been following the spread of misinformation and fear mongering. So, I will weigh in my thoughts as a person who has built racing engines, tuned cars on my dyno, raced on a competitive level, & built many fast cars when I owned a shop. (BTW It was fun. But, I don't miss the shop life)

Take this with a grain of salt. It's just 1 guys opinion that is based on factual information, first and second hand experience, talking with my buddies who are E85 tuned stock hubs, talking with people who slipped. etc... But, you all know what they say about opinions.

Is this crank hub thing real? Yes, It is. But, that does not mean every car is a ticking time bomb. No, not even close to it. It comes down to how you are driving the car. Nobody has answers and people think it's this or that. Or the year or manual or dct. So let me explain.

I believe this is due to 2 simple things. High torque and low rpm. When you have massive torque at 2000 rpm that is what causes the bolt to back out and that loss of torque on the hub will allow the timing chain sprocket to slip. And it's a slip not spinning freely 360 degrees. It's ok to have high torque at higher rpm because the engine is spinning faster. But, not so much at low rpm. It's fun though. But, no bueno for that bolt from backing out.

Think about it logically for a moment. The timing sprocket is under load with heavy boost and cylinder pressures. Do you think the cylinder pressures are enough to hulka-maniac it's way through a fully torqued factory crank bolt? Like raaaawr & just take out your entire motor, just like that.... Really? I can see if the bolt backs out and you lose torque. But, not if it's fully torqued. Get outta here with that.


If you are tuned or even w/ high torque of the E85 and running stock crank hub. Just do these things to avoid an issue:

No burnouts, no doughnuts, no kickdowns, no launching, no downshift UNDER high torque. Lift of the gas and downshift all you want. Don't rip the car at low engine speeds and high torque. Get on it from a 50 roll 60 roll all day long. Have fun with rolls and higher speeds all day. Just be mindful.

If you wanna send it, If you are going 600 700 800 whp and a lot of torque, wanna do burnouts etc then just do a crank hub fix. They are all really good. They all do the same thing. It's the labor cost that will kill your wallet. That VTT V2 looks like a good option though. Because, it installs so easily. Much easier then the 2 or 4 pin. If they all do the same. Then my logic says. Go with the path of least resistance. Lighter on the wallet and simpler installation makes the most sense. 2 pin 4 pin are great too. Just a lot more work and messy. They work just fine too. It's your preference.

If you're stock, just send it! You're fine. Your motor is not going to blow up at any second. Get outta here with that too. But, I would be mindful.

Valves don't bend because of pistons hitting them. They bend from intake valve colliding with them. Then when bent enough the pistons comes up and snaps it off eventually. But, that can only really happen from very bad valve float and under extreme conditions.

I've seen some shops crank the bolt over and over when the car comes in with slipped hub. Why?? That is causing more damage. I would not do that. If the car is out of time. Don't do that. Just fix it.

For context. My car is stock. I'm just waiting for my parts to arrive. Probably stage 2 Ecutek e85 max effort tune to start things off. I drive the car and enjoy it. I have launched it before. Yes, I take it to canyons and backroads and really put this car through its paces as an all around sports sedan. The car see's a lot of 40 & 60 rolling start races. I have burned out a few times. As of lately I follow my guideline to the T.

I plan to run crank hub fix. Only because, I plan to send it with bigger turbos. So, i will do them at the same time. Most likely it will stay on stock turbos and follow the guidelines till then.

I'm going with the VTT V2 crank hub fix for it's quality. It works perfectly under high stress, easy to install and the most cost effective. No brainer.

I'm not ripping on any shops or companies. I'm just an enthusiast and just sick of every other post about the same thing. All this fear mongering and people genuinely getting stressed about their cars. That sucks & I think it's blown out of proportion.

If you're going to send it. Just put one on. Any of them. it doesn't matter. They all do the same thing.


(Was trying to edit some grammar and I accidentally deleted some stuff. I don't remember right now lol But, ya. This is the gist of it.)

Just my 2 cents guys.

Cheers,

Max-
Can you elaborate what a "downshift UNDER high torque" is?

I am really torn between getting a CBC or full fix. I am at good power (no E85 though), 6MT, and I don't do burnouts, floor it at low RPM, etc. But still conerned!
Do CBC it's cheap fix and will definitely be better then not if your worried.

Downshifting while on the gas in a high torque situation.
__________________
IG @papasmurf_m3

ecutek - bend calibration - flex fuel - mpe - oem+
Appreciate 0
      10-24-2020, 04:05 AM   #251
Graves
Sicario
Graves's Avatar
Germany
917
Rep
1,095
Posts

Drives: 2018 M3 ZCP
Join Date: Jul 2017
Location: Bayern

iTrader: (1)

Garage List
Quote:
Originally Posted by papasmurf_m3 View Post
Quote:
Originally Posted by Electric View Post
Quote:
Originally Posted by papasmurf_m3 View Post
I've been following the spread of misinformation and fear mongering. So, I will weigh in my thoughts as a person who has built racing engines, tuned cars on my dyno, raced on a competitive level, & built many fast cars when I owned a shop. (BTW It was fun. But, I don't miss the shop life)

Take this with a grain of salt. It's just 1 guys opinion that is based on factual information, first and second hand experience, talking with my buddies who are E85 tuned stock hubs, talking with people who slipped. etc... But, you all know what they say about opinions.

Is this crank hub thing real? Yes, It is. But, that does not mean every car is a ticking time bomb. No, not even close to it. It comes down to how you are driving the car. Nobody has answers and people think it's this or that. Or the year or manual or dct. So let me explain.

I believe this is due to 2 simple things. High torque and low rpm. When you have massive torque at 2000 rpm that is what causes the bolt to back out and that loss of torque on the hub will allow the timing chain sprocket to slip. And it's a slip not spinning freely 360 degrees. It's ok to have high torque at higher rpm because the engine is spinning faster. But, not so much at low rpm. It's fun though. But, no bueno for that bolt from backing out.

Think about it logically for a moment. The timing sprocket is under load with heavy boost and cylinder pressures. Do you think the cylinder pressures are enough to hulka-maniac it's way through a fully torqued factory crank bolt? Like raaaawr & just take out your entire motor, just like that.... Really? I can see if the bolt backs out and you lose torque. But, not if it's fully torqued. Get outta here with that.


If you are tuned or even w/ high torque of the E85 and running stock crank hub. Just do these things to avoid an issue:

No burnouts, no doughnuts, no kickdowns, no launching, no downshift UNDER high torque. Lift of the gas and downshift all you want. Don't rip the car at low engine speeds and high torque. Get on it from a 50 roll 60 roll all day long. Have fun with rolls and higher speeds all day. Just be mindful.

If you wanna send it, If you are going 600 700 800 whp and a lot of torque, wanna do burnouts etc then just do a crank hub fix. They are all really good. They all do the same thing. It's the labor cost that will kill your wallet. That VTT V2 looks like a good option though. Because, it installs so easily. Much easier then the 2 or 4 pin. If they all do the same. Then my logic says. Go with the path of least resistance. Lighter on the wallet and simpler installation makes the most sense. 2 pin 4 pin are great too. Just a lot more work and messy. They work just fine too. It's your preference.

If you're stock, just send it! You're fine. Your motor is not going to blow up at any second. Get outta here with that too. But, I would be mindful.

Valves don't bend because of pistons hitting them. They bend from intake valve colliding with them. Then when bent enough the pistons comes up and snaps it off eventually. But, that can only really happen from very bad valve float and under extreme conditions.

I've seen some shops crank the bolt over and over when the car comes in with slipped hub. Why?? That is causing more damage. I would not do that. If the car is out of time. Don't do that. Just fix it.

For context. My car is stock. I'm just waiting for my parts to arrive. Probably stage 2 Ecutek e85 max effort tune to start things off. I drive the car and enjoy it. I have launched it before. Yes, I take it to canyons and backroads and really put this car through its paces as an all around sports sedan. The car see's a lot of 40 & 60 rolling start races. I have burned out a few times. As of lately I follow my guideline to the T.

I plan to run crank hub fix. Only because, I plan to send it with bigger turbos. So, i will do them at the same time. Most likely it will stay on stock turbos and follow the guidelines till then.

I'm going with the VTT V2 crank hub fix for it's quality. It works perfectly under high stress, easy to install and the most cost effective. No brainer.

I'm not ripping on any shops or companies. I'm just an enthusiast and just sick of every other post about the same thing. All this fear mongering and people genuinely getting stressed about their cars. That sucks & I think it's blown out of proportion.

If you're going to send it. Just put one on. Any of them. it doesn't matter. They all do the same thing.


(Was trying to edit some grammar and I accidentally deleted some stuff. I don't remember right now lol But, ya. This is the gist of it.)

Just my 2 cents guys.

Cheers,

Max-
Can you elaborate what a "downshift UNDER high torque" is?

I am really torn between getting a CBC or full fix. I am at good power (no E85 though), 6MT, and I don't do burnouts, floor it at low RPM, etc. But still conerned!
Do CBC it's cheap fix and will definitely be better then not if your worried.

Downshifting while on the gas in a high torque situation.
Excellent point about the aggressive downshifts. My car is not tuned and I for a fact, drive it very hard. I down shift in high RPM and kick down. I always have the trans in S3 when I'm driving hard as well. I have a BM3 but I am waiting until I do the keyed hub cause honestly, the way I drive I am asking for trouble. The CBC may be sufficient as well to be honest, but it doesn't prevent the friction washer from grenading.
__________________
Ryan King
2018 M3 ZCP
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 06:29 AM.




f80post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, 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