[Karmic Man]

Originally Posted by M3 Adjuster

apparently you have zero faith in your body shop or your body shop simply SUCKS.

It does amaze me how much respect shows like American Chopper, overhaulin' and such get for metalwork and custom fabrication, and the moment a car gets a hickey it should be totaled and salvaged because " it will never be right again".

I've had wheel repair companies repair and paint wheels that I use on the track. I've had a machine shop weld an aluminum s14 cylinder head that a crack in a water jacket and it never overheated again. I've had an aluminum oil pan welded and it never leaked. I've had frame repairs on a car and never had an issue again. I've had a windshield replaced and it didn't have wind noise afterwards.

I'm sure there are competent shops that can install a CF roof on an M2... as well as repair suspension damage , minor frame repair , wheel repair and alignment work.

I wouldn't trust every single BMW dealer to all of the work listed above, but certainly every major city in the top 200 majors cities in the US has multiple repair ships that can do excellent work. It's simply a matter of doing ones due diligence and finding a shop that does great work at a great price and is enthusiastic about doing a quality repair.

I've seen one man, ten man, 100 man, and 1000 shop mega chains all do both horrible and quality work. I personally prefer a medium size independent shop over the local dealer body shop.

It’s more to do with metal fatigue. Once the metal is bent from its original shape it is weakened. Benting it again during panel alignment will weaken it further.

It will take less force to bent that piece of metal next time round. I can’t tell you how much weaker by percentage as there are myriad variables involved but the car simply won’t drive the same again.

[Fedorov]

I'm glad I had the e92 335i for many years before I bought my M2. It taught me a lot about the feeling of a more powerful rear wheel drive car, especially in the wet.

The most important thing is that there were no physical injuries to your person though.

[M3 Adjuster]

Originally Posted by Karmic Man

It's more to do with metal fatigue. Once the metal is bent from its original shape it is weakened. Benting it again during panel alignment will weaken it further.

It will take less force to bent that piece of metal next time round. I can't tell you how much weaker by percentage as there are myriad variables involved but the car simply won't drive the same again.

Completely erroneous.

Before you start thinking about metal fatigue... look up metal memory .... the ability of metal to return to the shape it was molded in.

As you mention there are many variables involved , one of them being the thicker the metal, the more resistant it is to bending , and it also has a better memory effect.

Of course metal fatigue *is* an issue but that would be after multiple (as in *many* , not a couple ) manipulations of the metal.

In other words,

1- don't quit your day job.
2- I was correct, you absolutely need a little more faith in your repair shop.

A good repair shop will never attempt to repair something they know is irreparably damaged. That would clearly be putting the customer in a dangerous situation. That's generally not good for return business.

Your opinion on repairs seems to be at best formed from incorrect information and perhaps minimal personal experience. The best way to keep that is to immediately trade in any damaged vehicle , that way you never will be exposed to a situation that could change your opinion

[Karmic Man]

Originally Posted by M3 Adjuster

Completely erroneous.

Before you start thinking about metal fatigue... look up metal memory .... the ability of metal to return to the shape it was molded in.

As you mention there are many variables involved , one of them being the thicker the metal, the more resistant it is to bending , and it also has a better memory effect.

Of course metal fatigue *is* an issue but that would be after multiple (as in *many* , not a couple ) manipulations of the metal.

In other words,

1- don't quit your day job.
2- I was correct, you absolutely need a little more faith in your repair shop.

A good repair shop will never attempt to repair something they know is irreparably damaged. That would clearly be putting the customer in a dangerous situation. That's generally not good for return business.

Your opinion on repairs seems to be at best formed from incorrect information and perhaps minimal personal experience. The best way to keep that is to immediately trade in any damaged vehicle , that way you never will be exposed to a situation that could change your opinion

My friend you are simply wrong here. Metal doesn't have "memory" that retains its strength unless its those shape memory alloys which you won't find on the M2. The piece of metal might be able to be bended back to its original shape but it is structurally weaker afterwards. The reason is its crystalline structure has been altered. In fact to straighten a piece of metal after it is bent you are altering its crystalline structure twice.

It has nothing to do with the quality of the repair shop.

The quality of the repair shop is of course important but it can't change physics. Also even good repair shops have variations on the quality of work depending on the workers mood of the day.

I wouldn't recommend OP to rest his faith on a 'good repair shop' if the frame has to be straighten out on a frame rack. It's for his benefit, not mine. If the frame is fine then there is a reason to keep the M2 but he should still request the body shop to change the subframe to a new one from BMW.

So...

1. I will still keep my job
2. Don't put too much faith in a repair shop no matter how good it is

[M3 Adjuster]

Originally Posted by Karmic Man

My friend you are simply wrong here. Metal doesn't have "memory" that retains its strength unless its those shape memory alloys which you won't find on the M2. The piece of metal might be able to be bended back to its original shape but it is structurally weaker afterwards. The reason is its crystalline structure has been altered. In fact to straighten a piece of metal after it is bent you are altering its crystalline structure twice.

It has nothing to do with the quality of the repair shop.

The quality of the repair shop is of course important but it can't change physics. Also even good repair shops have variations on the quality of work depending on the workers mood of the day.

I wouldn't recommend OP to rest his faith on a 'good repair shop' if the frame has to be straighten out on a frame rack. It's for his benefit, not mine. If the frame is fine then there is a reason to keep the M2 but he should still request the body shop to change the subframe to a new one from BMW.

So...

1. I will still keep my job
2. Don't put too much faith in a repair shop no matter how good it is

thanks Chicken Little.. but There is an entire repair industry that disproves you. I'll just leave these here and move on.


https://www.explainthatstuff.com/how...ory-works.html

https://www.3m.com/3M/en_US/collisio...ns/metal-shop/


https://www.i-car.com/

As stated previously.. *your* best bet is to sell and move on.. The OP ( as well as other ) can of course make his own (hopefully more well informed) decision.

Having been in the OP position before personally, as an owner of an E30 M3 that I crashed and caused thousands of dollars of damage to in 1996...

I can unequivocally state that after $14K repairs to what at the time was a 21K vehicle.. .. my E30 M3 was repaired MAGNIFICENTLY. I loved it, tracked it and cared for it another ELEVEN years after the collision repair and never had an issue with the repair work (paint matched.. never faded... never had any clearcoat issues ) or the metal work which included FRAME REPAIR. (EEK!!!) Years after the repairs.. I installed an aftermarket coilover suspension and was able to be aligned easily.

When I decided to improve the engine bay by adding a STRUT bar.. I simply jacked up one side of the car (the common install method) and undid the 3 bolts on each shock tower.. and bam it dropped into place and I bolted it down. This is after YEARS and many miles of being TRACKED after the repair.

Since I am waxing poetic.. the little shop that did my repairs is still around and they deserve a shout out. https://www.yelp.com/biz/jons-body-shop-lafayette

Originally Posted by bmwm22018

Quick update: spoken to the bodyshop - it will be repaired but going to cost around £18k of work. New suspension front and back, new steering rack, door, sill, alloys. part of the sub frame is very slightly bent but the guy said it can be strengthened to good as new.... going down tomorrow to find out more.

Good news is once insurance company give the go ahead and parts are there it will only take around 2 weeks according to the mechanic so i might be back on the roads sooner than expected. I have an advanced driving day booked in august where there will be track driving, including wet driving, and an instructor in the car with me which i think will be very useful.

Finally just want to thank everyone for being so supportive, never expected as much of a response, thank you all very much

There will always be people that will tell you " your car won't be the same anymore" ... and it simply is not true. For the MAJORITY of people that experience collision repairs.. the vehicle is repaired properly. it sounds as if your repairer is very confident they can do a quality repair. That's always reassuring.

Believe you me... when I was sitting in your shoes... It was very comforting to talk to my shop guys who were ABSOLUTELY CONFIDENT in their SKILLZ, excited to do their work.. and excited to demonstrate the quality work they can do. That confidence was reassuring and they did indeed do excellent work. Hopefully when you get your car back, you find that this is the case for you as well

[Nezil]

I can't speak with nearly as much authority as M3 Adjuster, but I do know that the entire paintless dent removal industry makes use of the memory affect of metal in panels.

I know it looks like there is a lot of massaging of metal, but the pros that do this will tell you that a lot of the work is done for them by using heat and the memory affect of the metal.

I've had a dent removed by PDR and it's magical to see happen.

[Karmic Man]

Originally Posted by M3 Adjuster

thanks Chicken Little.. but There is an entire repair industry that disproves you. I'll just leave these here and move on.


https://www.explainthatstuff.com/how...ory-works.html

https://www.3m.com/3M/en_US/collisio...ns/metal-shop/


https://www.i-car.com/

As stated previously.. *your* best bet is to sell and move on.. The OP ( as well as other ) can of course make his own (hopefully more well informed) decision.

Having been in the OP position before personally, as an owner of an E30 M3 that I crashed and caused thousands of dollars of damage to in 1996...

I can unequivocally state that after $14K repairs to what at the time was a 21K vehicle.. .. my E30 M3 was repaired MAGNIFICENTLY. I loved it, tracked it and cared for it another ELEVEN years after the collision repair and never had an issue with the repair work (paint matched.. never faded... never had any clearcoat issues ) or the metal work which included FRAME REPAIR. (EEK!!!) Years after the repairs.. I installed an aftermarket coilover suspension and was able to be aligned easily.

When I decided to improve the engine bay by adding a STRUT bar.. I simply jacked up one side of the car (the common install method) and undid the 3 bolts on each shock tower.. and bam it dropped into place and I bolted it down. This is after YEARS and many miles of being TRACKED after the repair.

Since I am waxing poetic.. the little shop that did my repairs is still around and they deserve a shout out. https://www.yelp.com/biz/jons-body-shop-lafayette



There will always be people that will tell you " your car won't be the same anymore" ... and it simply is not true. For the MAJORITY of people that experience collision repairs.. the vehicle is repaired properly. it sounds as if your repairer is very confident they can do a quality repair. That's always reassuring.

Believe you me... when I was sitting in your shoes... It was very comforting to talk to my shop guys who were ABSOLUTELY CONFIDENT in their SKILLZ, excited to do their work.. and excited to demonstrate the quality work they can do. That confidence was reassuring and they did indeed do excellent work. Hopefully when you get your car back, you find that this is the case for you as well

Oh my mr goosey what ever you quoted was nothing about the effect on the strength of metal after collision. What I said didn't change scientifically so why bother

Vouching with a personal experience from a E30? Bless us all. Do you have something from more recent? The M2 is much heavier and has loads more power than the E30. Not to mention different alloys are used on the M2 than the E30 and different chassis design. The M2 is a much more complicated car. You vouch from 1 good experience on an old car and you think the result will be the same for all cars...

I am sure the OP will manage to figure what to do. Your overly colourful input will just confuse people.

[bmwm22018]

Hi guys thanks for your responses - I guess i will not know how the car will feel until i get it back. My understanding based on speaking to the garage is that if the sub frame needed replacing they would replace it - they are not really working to a budget as they said they simply replace everything that is or may be damaged and repair things that can be repaired - if there was any doubt they would simply replace the part as the insurance company will be paying for it...

So far the dealership and bodyshop have been nothing but helpful and have managed to fill me with confidence in their skills so i am going to put my trust in them for the time being... That said it may well be that i get it back and it doesnt feel right. in which case i would take it back to the dealership and consider moving on/buying a new M2. I will update the thread when i get the car back on the road in hopefully 3 weeks time.

[Mavus]

Originally Posted by Karmic Man

My friend you are simply wrong here. Metal doesn't have "memory" that retains its strength unless its those shape memory alloys which you won't find on the M2. The piece of metal might be able to be bended back to its original shape but it is structurally weaker afterwards. The reason is its crystalline structure has been altered. In fact to straighten a piece of metal after it is bent you are altering its crystalline structure twice.

It has nothing to do with the quality of the repair shop.

The quality of the repair shop is of course important but it can't change physics. Also even good repair shops have variations on the quality of work depending on the workers mood of the day.

I wouldn't recommend OP to rest his faith on a 'good repair shop' if the frame has to be straighten out on a frame rack. It's for his benefit, not mine. If the frame is fine then there is a reason to keep the M2 but he should still request the body shop to change the subframe to a new one from BMW.

So...

1. I will still keep my job
2. Don't put too much faith in a repair shop no matter how good it is

There is something called "fatigue life" and "ultimate load" used to design metallic structures based on the expected number of stress cycles.

Every single metallic component has its fatigue life. There are several variables that are taken as inputs and entered into sophisticated models to predict fatigue life based on material properties, expected loads, object shape, length, width, height, environmental conditions etc.

When the car travels on the road there are parts of the chassis that flex more than others based on the loads in the x, y, and z axis. This is all modeled mathematically and analyzed. Once the actual fatigue life is determined some components may get bigger and some smaller. This is done during system optimization. If the part needs additional strength that usually means additional weight as it becomes thicker (stronger).

The folks responsible for the design and analysis are structural engineers. Therefore, if a component is damaged "beyond repair" it will be replaced. However, a single impact to a metallic component does not instantly mean that it will be weaker. On an old car it is very likely but on a new car the impact would need to be severe. The inspection procedure specified by the manufacturer will help determine the level of repair needed as specified in the repair procedures defined by structural engineers.

For anybody interested in the details research stress analysis and fatigue life.

[Karmic Man]

Originally Posted by Smooth 330i

There is something called "fatigue life" and "ultimate load" used to design metallic structures based on the expected number of stress cycles.

Every single metallic component has its fatigue life. There are several variables that are taken as inputs and entered into sophisticated models to predict fatigue life based on material properties, expected loads, object shape, length, width, height, environmental conditions etc.

When the car travels on the road there are parts of the chassis that flex more than others based on the loads in the x, y, and z axis. This is all modeled mathematically and analyzed. Once the actual fatigue life is determined some components may get bigger and some smaller. This is done during system optimization. If the part needs additional strength that usually means additional weight as it becomes thicker (stronger).

The folks responsible for the design and analysis are structural engineers. Therefore, if a component is damaged "beyond repair" it will be replaced. However, a single impact to a metallic component does not instantly mean that it will be weaker. On an old car it is very likely but on a new car the impact would need to be severe. The inspection procedure specified by the manufacturer will help determine the level of repair needed as specified in the repair procedures defined by structural engineers.

For anybody interested in the details research stress analysis and fatigue life.

An impact that change the shape of the metal permanently is not the same as an impact that retains the shape of the metal.

When the original shape of the metal is deformed and then get pressed back to its original shape, its crystalline structure has been altered and therefore it will lose its strength.

An introductory session on frame damage for those who are interested (but don't click their ad stuff

https://carbrain.com/Blog/what-is-frame-damage

[Karmic Man]

Originally Posted by bmwm22018

Hi guys thanks for your responses - I guess i will not know how the car will feel until i get it back. My understanding based on speaking to the garage is that if the sub frame needed replacing they would replace it - they are not really working to a budget as they said they simply replace everything that is or may be damaged and repair things that can be repaired - if there was any doubt they would simply replace the part as the insurance company will be paying for it...

So far the dealership and bodyshop have been nothing but helpful and have managed to fill me with confidence in their skills so i am going to put my trust in them for the time being... That said it may well be that i get it back and it doesnt feel right. in which case i would take it back to the dealership and consider moving on/buying a new M2. I will update the thread when i get the car back on the road in hopefully 3 weeks time.

Great, keep us posted

[Poochie]

Originally Posted by Karmic Man

When the original shape of the metal is deformed and then get pressed back to its original shape, its crystalline structure has been altered and therefore it will lose its strength.

An introductory session on frame damage for those who are interested (but don't click their ad stuff

Great info but damage of this sort, they are not going to straitened & Bondo-up that panel; but instead cut out the damage section of quarter panel and MIG-weld another new piece together..

So the argument of weaken metal is moot.. However, if the R&R quarter panel is not aligned properly, the tire will rub on panel every time you hit a bump.. Ask me how I know:

[azibux1]

Any more details on the course you're going to be doing? Is it in your own car? Cost? Location? Thanks!

[Tralfaz]

Originally Posted by Poochie

Great info but damage of this sort, they are not going to straitened & Bondo-up that panel; but instead cut out the damage section of quarter panel and MIG-weld another new piece together..

So the argument of weaken metal is moot.. However, if the R&R quarter panel is not aligned properly, the tire will rub on panel every time you hit a bump.. Ask me how I know:

Even when done correctly, the one downside is that there are a limited number of times they can do this before the repair becomes more complicated/expensive. I got rear ended twice in my 135 with both involving repairs to mostly the same areas. After the 2nd accident the repair guy told me that if I got rear ended again, they wouldn't have enough metal left to just cut away damaged area and weld on a new part again.

[bmwm22018]

Originally Posted by azibux1

Any more details on the course you're going to be doing? Is it in your own car? Cost? Location? Thanks!

Yeah so i haven't got one in my own car as yet... this one is actually a porsche driving experience (booked with a friend who coincidentally bought a porsche recently). I will be driving a 911 991.2 Carrera (PDK) at the porsche driving experience centre at silverstone. You have a professional driving instructor in the passenger seat with you as you go round the track - you can choose what you would like to focus on... they can wet part of the track so you get practice driving in different conditions etc so i will be going for that i think The experience cost £470 and its a 4 hour course.

I plan on doing one in my own car somewhere more local soon, talking of which if you have any recommendations i would be most grateful!

[Doctor///M]

Originally Posted by Smooth 330i

There is something called "fatigue life" and "ultimate load" used to design metallic structures based on the expected number of stress cycles.

Every single metallic component has its fatigue life. There are several variables that are taken as inputs and entered into sophisticated models to predict fatigue life based on material properties, expected loads, object shape, length, width, height, environmental conditions etc.

When the car travels on the road there are parts of the chassis that flex more than others based on the loads in the x, y, and z axis. This is all modeled mathematically and analyzed. Once the actual fatigue life is determined some components may get bigger and some smaller. This is done during system optimization. If the part needs additional strength that usually means additional weight as it becomes thicker (stronger).

The folks responsible for the design and analysis are structural engineers. Therefore, if a component is damaged "beyond repair" it will be replaced. However, a single impact to a metallic component does not instantly mean that it will be weaker. On an old car it is very likely but on a new car the impact would need to be severe. The inspection procedure specified by the manufacturer will help determine the level of repair needed as specified in the repair procedures defined by structural engineers.

For anybody interested in the details research stress analysis and fatigue life.

The know-it-alls that brashly interjected in this thread is not atypical, but thanks for your insight in providing a much more measured approach. So much misinformation can truly become confusing to those who are unfamiliar. Where my material scientists at?!

Glad things got resolved and you shared your experience with us OP. Seriously not a situation we'd want to find ourselves in, and many HPDEs will help you better understand the limits of the car.

[rich8566]

Please update us on the status of the repair. Photos and total cost too if you're ok sharing. Many thanks.

[GoneIn4Secs]

I think the OP mustve had been in sport mode and had traction off when he had the slip out at the roundabout

[akkando]

Originally Posted by GoneIn4Secs

I think the OP mustve had been in sport mode and had traction off when he had the slip out at the roundabout

No such thing as Sport AND traction off. Turning the traction off is its very own mode. It's not intuitive, they could have just put all five modes on the one rocker button and it would be more easily understood. Perhaps they felt they needed a dedicated button for traction off mode though for safety reasons.

[bmwm22018]

Originally Posted by rich8566

Please update us on the status of the repair. Photos and total cost too if you're ok sharing. Many thanks.

insurance company approved the work and its underway should have the car back within the next 2 weeks. total damage around £18k *eeek*

Originally Posted by GoneIn4Secs

I think the OP mustve had been in sport mode and had traction off when he had the slip out at the roundabout

I always drive it in sport but i usually do it before i set off - that morning i did it on the move and didn't look at what i was doing and i think i must have pressed the wrong button ... nothing would possess me to intentionally turn the DSC off, in the wet, in a new car im not familiar with. daft mistake to make.

[flyaway]

Originally Posted by bmwm22018

I always drive it in sport but i usually do it before i set off - that morning i did it on the move and didn't look at what i was doing and i think i must have pressed the wrong button ... nothing would possess me to intentionally turn the DSC off, in the wet, in a new car im not familiar with. daft mistake to make.

You can't turn off DSC with a simple push and even if you touched the respective button you are in Traction mode clearely marked on the display and main panel as is the Sport+ mode with limited TC/DSC. So it seems to me you were in Sport mode most probably and effectively (and objectively) you should review and adapt your RWD driving skills. Glad no one was harmed, good luck!

[bmwm22018]

final update for those interested!

Took a lot longer than expected to repair the car however it is now back and i picked it up the other night around 5 weeks on from the accident. It feels good as new and the body shop have done a fantastic job. I was worried about there being rattles/squeaks etc and it not 'feeling' right but i honestly can't tell the difference - it feels good as new.

Cant beat the feeling of getting it back after 5 weeks without it