Video: World's fastest BMW F10 M5 by Manhart Racing - Brake disc getting hot & smokin

[iPeng]

Hello

I record this video on an airport in Germany. This M5 was doing some laps together with 2 other M-cars from Manhart Racing

This is world's fastest BMW F10 M5 at the moment with 710HP and 860Nm!

BMW M5 F10 MH5 S Biturbo - Stage 4 Performance Kit:

MHR Software Remapping
MHR Downpipes (semi-catted)
MHR Axleback Exhaust
Carbon Air Intake System
MHR Performance Box

100-200 km/h in 6,3 seconds
80-250 km/h in 13,5 seconds
0-100 km/h in 3,9 seconds
0-60 km/h in 2,6 seconds

[Simon*X]

Haha nice.. the stock brakes had some problems performing on a tight track like this mounted on a 2 ton car

[Hunter5179]

Awesome! Great job Manhart

[singularity]

Btw brake discs smoking is very normal, I once braked 'fast' from 300 km/h to a standstill and a friend of mine lit a cigarette (or so he claimed) on my brake discs, either way they were smoking

[wrsbmw]

Originally Posted by singularity

Btw brake discs smoking is very normal, I once braked 'fast' from 300 km/h to a standstill and a friend of mine lit a cigarette (or so he claimed) on my brake discs, either way they were smoking

Makes sense, all that kinetic energy is converted to heat through friction. The kinetic energy of the car is proportional to v**2 so those high speeds really require a lot of heat to be absorbed by the brake disks if they are being used to do a complete stop. This is why they need to be so big along with the need for increased surface area in order to produce enough friction between the surfaces to stop from high speeds or slow down quickly from high to low speeds.

Of course this is also why you will wear out your car quickly by tracking it. Same thing happens in the engine. All of the moving components are affected similarly and the energy is mostly dissipated as heat. This is also why you shouldn't really race a stock car. It's not built or designed to handle the kinds of prolonged heat that the constant changing from high to low speed on a track will produce.

I know people do it but I also think they do it with a second car, not their regular car. Right?

[Boss330]

Originally Posted by wrsbmw

Of course this is also why you will wear out your car quickly by tracking it. Same thing happens in the engine. All of the moving components are affected similarly and the energy is mostly dissipated as heat. This is also why you shouldn't really race a stock car. It's not built or designed to handle the kinds of prolonged heat that the constant changing from high to low speed on a track will produce.

I know people do it but I also think they do it with a second car, not their regular car. Right?

Are you saying that the G-forces are affecting the engine in a bad way, or that the use of the engines power is something the engine is not designed to withstand?

Off course a engine that is driven leisurely (but not so leisurely that it gets carbon deposits etc) will normally last longer than a engine that is run at full throttle. But I don't think that BMW ///M hasn't taken into consideration that their engines will be used extensively at high speeds on the Autobahn or on track days. In fact BMW even arranges track days... And has the 'Ring Taxi M5 which is driven hard around the Nürburgring.

[wrsbmw]

Originally Posted by Boss330

Are you saying that the G-forces are affecting the engine in a bad way, or that the use of the engines power is something the engine is not designed to withstand?

Off course a engine that is driven leisurely (but not so leisurely that it gets carbon deposits etc) will normally last longer than a engine that is run at full throttle. But I don't think that BMW ///M hasn't taken into consideration that their engines will be used extensively at high speeds on the Autobahn or on track days. In fact BMW even arranges track days... And has the 'Ring Taxi M5 which is driven hard around the Nürburgring.

No, not the G forces. I am talking about the constant high speed to low speed and back transitions. The kinetic energy of the car is proportional to V**2. If you look at the curve, you see that energy levels are substantially higher at 100mph than 50mph. The kinetic energy of the car is 4 times as high at 100mph as it is at 50mph. At 150mph it is 9 times as much as at 50mph. So braking from 150mph down to 80mph to take one of the corners on the COTA creates far more heat than braking from 50mph to 0mph. Even braking from 100mph to 50mph requires dissipating three times the energy as from 50mph to 0mph. That energy is usually dissipated in the form of heat and heat wears out engine components, brakes and tires too. It also stresses all of the rotating components as well.

Running the car at a constant high speed isn't the same as tracking it. The speed is constant and the energy is constant. So there isn't a lot of heat generated due to frequent change in energy levels. This is why tracking the car will wear it out quickly. I am sure the engineers at BMW didn't design the car to be tracked on a regular basis, not within the warranty anyway.

OCICBW but I don't intend to track my car regularly.

[Boss330]

I know that the brakes generates more heat/energy braking the car down from higher speeds. But it wasn't the brakes I was asking about, it was the engine (as that was one of your concerns).

To reiterate my question, do you still believe that the engine in a ///M car isn't suited for track use? And if so, why?

[singularity]

Originally Posted by wrsbmw

Makes sense, all that kinetic energy is converted to heat through friction. The kinetic energy of the car is proportional to v**2 so those high speeds really require a lot of heat to be absorbed by the brake disks if they are being used to do a complete stop. This is why they need to be so big along with the need for increased surface area in order to produce enough friction between the surfaces to stop from high speeds or slow down quickly from high to low speeds.

Of course this is also why you will wear out your car quickly by tracking it. Same thing happens in the engine. All of the moving components are affected similarly and the energy is mostly dissipated as heat. This is also why you shouldn't really race a stock car. It's not built or designed to handle the kinds of prolonged heat that the constant changing from high to low speed on a track will produce.

I know people do it but I also think they do it with a second car, not their regular car. Right?

Makes sense now, thanks for the insight

[wrsbmw]

Originally Posted by Boss330

I know that the brakes generates more heat/energy braking the car down from higher speeds. But it wasn't the brakes I was asking about, it was the engine (as that was one of your concerns).

To reiterate my question, do you still believe that the engine in a ///M car isn't suited for track use? And if so, why?

Like I said, it's all the moving parts, particularly the pistons and flywheel that would be affected in the engine. More work is being done by the engine in the acceleration phases than if it was just at a constant speed. Getting the energy of the car up to the requirement for a given velocity requires work to accelerate the mass of the car. After it has gained speed, it only requires additional energy to counteract friction and air resistance. The cornering requires the car slow down and speed up, repeatedly. This stresses the moving components much more than if they were just moving at a constant fixed rate.

Of course you know that city driving you get less mileage than highway and this is the same principle. More work is done by the engine in stop start or speed up and slow down than just running at constant speed. It is this additional work that dissipates the greater power and also subjects the components to dynamic stress.

Higher RPM in the lower gears are required to accelerate the car to a given velocity. You don't run the car at the top of the power band in the stretches nor would you on the highway even at 120mph. In order to get the car to the high speed, the engine must rev higher in the powerband and it must do it repeatedly when tracking the car. This puts more stress on the engine than if you were just running it up to say 120mph and leaving it at 3500 RPM in 7th gear for 30 minutes or an hour.

So yes, the engine is subject to much greater stress due to tracking because I am sure the average RPM is much higher. That is reflected in the lower gas mileage due to the greater amount of power dissipation/consumption.

[Boss330]

Originally Posted by wrsbmw

Like I said, it's all the moving parts, particularly the pistons and flywheel that would be affected in the engine. More work is being done by the engine in the acceleration phases than if it was just at a constant speed. Getting the energy of the car up to the requirement for a given velocity requires work to accelerate the mass of the car. After it has gained speed, it only requires additional energy to counteract friction and air resistance. The cornering requires the car slow down and speed up, repeatedly. This stresses the moving components much more than if they were just moving at a constant fixed rate.

Of course you know that city driving you get less mileage than highway and this is the same principle. More work is done by the engine in stop start or speed up and slow down than just running at constant speed. It is this additional work that dissipates the greater power and also subjects the components to dynamic stress.

Higher RPM in the lower gears are required to accelerate the car to a given velocity. You don't run the car at the top of the power band in the stretches nor would you on the highway even at 120mph. In order to get the car to the high speed, the engine must rev higher in the powerband and it must do it repeatedly when tracking the car. This puts more stress on the engine than if you were just running it up to say 120mph and leaving it at 3500 RPM in 7th gear for 30 minutes or an hour.

So yes, the engine is subject to much greater stress due to tracking because I am sure the average RPM is much higher. That is reflected in the lower gas mileage due to the greater amount of power dissipation/consumption.

What you are saying is of course basic knowledge for any mechanically trained/skilled/knowledgeable person. Running on the autobahn and doing repeated braking and accelerations requires more energy than running at a steady 65MPH, running on a track even more than on the Autobahn (depending on track layout). But remember that the M5 engine is designed to go at maximum speed for a long time on the Autobahn, longer than you can on a race track.

My question wasn't whether a engine is more stressed on a track than it is cruising at 65MPH. The answer to that is quite obvious

My question is still if you still believe that the ///M5 engine isn't suited for extended track driving (as that was what you implied in your first post)?
And what in the engine design makes it unsuited for tracking (taking into consideration that the engine is designed to be driven extensively at 300+km/h on the Autobahn, with heavy braking and accelerations in between)?

Of course this is also why you will wear out your car quickly by tracking it. Same thing happens in the engine. All of the moving components are affected similarly and the energy is mostly dissipated as heat. This is also why you shouldn't really race a stock car. It's not built or designed to handle the kinds of prolonged heat that the constant changing from high to low speed on a track will produce.

If so, someone should tell BMW to reconsider ///M Driving School, ///M Track Days and the 'Ring Taxi

[wrsbmw]

Originally Posted by Boss330

If so, someone should tell BMW to reconsider ///M Driving School, ///M Track Days and the 'Ring Taxi

Those are expensive experiences and the cars are provided by BMW in the first two. I don't know what the last one is. Anyway, why don't you ask BMW if they designed the stock M5 for regular tracking and see what they tell you. I think they will tell you that you do so at your own risk and that tracking your vehicle is likely to be improper operation. The BMW warranty says that your car has a race-bred engine design. It doesn't say you have a racing engine in your car. It also doesn't warrant your car to be raced as that is specifically excluded by the warranty. You can take it to the track and run it around but if you keep doing that, it's going to break down and have some kind of serious malfunction that costs significant money as a result. That is what I mean by my comment. You can pretty much use a car any way you want, that doesn't mean that is what the designers intended.

If you want to kid yourself about the design of the car, be my guest. I can tell you as a guy who designed a lot of products both software and hardware, users always find new ways to use stuff that the designers never intended. They also find ways to break stuff that the designers never thought they could. That is why warranties are limited and written by weasel wording lawyers.

[Boss330]

Originally Posted by wrsbmw

Those are expensive experiences and the cars are provided by BMW in the first two. I don't know what the last one is. Anyway, why don't you ask BMW if they designed the stock M5 for regular tracking and see what they tell you. I think they will tell you that you do so at your own risk and that tracking your vehicle is likely to be improper operation. The BMW warranty says that your car has a race-bred engine design. It doesn't say you have a racing engine in your car. It also doesn't warrant your car to be raced as that is specifically excluded by the warranty. You can take it to the track and run it around but if you keep doing that, it's going to break down and have some kind of serious malfunction that costs significant money as a result. That is what I mean by my comment. You can pretty much use a car any way you want, that doesn't mean that is what the designers intended.

If you want to kid yourself about the design of the car, be my guest. I can tell you as a guy who designed a lot of products both software and hardware, users always find new ways to use stuff that the designers never intended. They also find ways to break stuff that the designers never thought they could. That is why warranties are limited and written by weasel wording lawyers.

From official BMW press releases:

http://www.bimmerpost.com/goodiesforyou/new_m5.pdf

Fifth generation of the world’s most successful high-performance saloon in the premium segment of the executive class; new BMW M5 is an exceptionally dynamic high-performance sports car with four doors and five seats; consistent further development of the vehicle concept initiated in 1984 with the first-generation BMW M5; compelling track potential combines with the comprehensive practicality of a luxurious business saloon; groundbreaking character headlined by significantly improved efficiency, supreme long-distance comfort, and innovative driver assistance systems and infotainment functions.

The precise interplay of the drive system, chassis and design has been refined in extensive and detailed testing on the Nordschleife circuit at the Nürburgring to ensure unbeatable longitudinal and lateral acceleration, handling characteristics and braking performance.

Added to which, the engine has an extremely powerful cooling system and wet sump lubrication optimised for high lateral loads. This is a combination without parallel worldwide and produces the suitably exclusive performance characteristics you would expect from a BMW M car. The experience is defined by instantaneous responses and extremely impressive pushing power developed from extremely low revs and maintained into the higher reaches of the engine speed range.

On the race track the new BMW M5 is every inch the high-performance sports car, but it also impresses on the journey there and back with the steady assurance and comfort of a premium-segment business sedan.

The engine powering the new BMW M5 boasts a dynamically optimised wet sump oil supply designed to work under top-end longitudinal and lateral acceleration. This ensures optimum engine lubrication is maintained under extremely dynamic acceleration, braking and cornering.

The new BMW M5 is a high-performance sports car whose exceptional dynamic potential is geared squarely to the demands of track use, yet which also sets a new benchmark in everyday driving with its supreme touring comfort. Chassis technology geared to the demands of racing, with stronger yet also more lightweight axle links and wheel carriers, enables precise handling even in extremely dynamic driving situations.
......

The precise interplay of powertrain, chassis and body has been fine-tuned down to the last detail during extensive testing at the Nürburgring’s Nordschleife circuit, and ensures peerless longitudinal and lateral acceleration, handling and braking.

Using large panels to fix the chassis to the front and rear axles optimises torsional rigidity and ensures that the dynamic forces are channelled evenly through the body. For example, the forces exerted on the anti-roll bars on one side of the car when clipping a kerb on the track are transferred evenly over the entire front section of the car.

while “Sport Plus” allows further stiffening of the suspension to achieve maximum longitudinal and lateral acceleration in ultra-dynamic driving situations on level race tracks.

Not sure I'm kidding myself about the design of M cars...

[wrsbmw]

Originally Posted by Boss330

Not sure I'm kidding myself about the design of M cars...

Engineers don't write marketing literature. Geez, what business are you in?

I personally could care less what you do with your car. I might track mine but probably won't the more I think about it. I have plenty of opportunity to put the pedal to the metal on the back roads of Texas.

I think the car is great but if I wanted a track car, this wouldn't be the one I bought for that purpose.

[Boss330]

Originally Posted by wrsbmw

Engineers don't write marketing literature. Geez, what business are you in?

I personally could care less what you do with your car. I might track mine but probably won't the more I think about it. I have plenty of opportunity to put the pedal to the metal on the back roads of Texas.

I think the car is great but if I wanted a track car, this wouldn't be the one I bought for that purpose.

So, first you say: Ask BMW if the car can be used/is designed for track use

I reply with: OFFICIAL BMW press releases, saying that in fact it is!

Then you suddenly figure out that since it's written by the PR department, and not the Engineers, it's worthless...

I wonder what business you are in Where I come from, even marketing people have a legal responsibilty not to misrepresent the product...

BTW, I'm a vehicle engineer.

Your original statement was that the car and engine wasn't designed for track use. BMW official press releases say otherwise. That still isn't good enough because it wasn't written by the right people and apparently is all made up by some marketing gurus

Whatever

That you would have chosen a different car for track days is a completely different subject and has no relevance to the question at hand (ie is the M5 designed to also be used on the track).

Regardless of whether one believes what BMW says about the M5, the MHR car in the video is a pretty awesome beast

[wrsbmw]

Obviously you wanted to nitpick my original statement and start an argument. Looks to me like you got nowhere. Tracking your car is considered improper use I am fairly certain. The warranty is voided if you race the car, that much is very clear.

PR is marketing material and nothing more. You can cut and paste all the statements you want about the car. Sure, put it on the track, ruin it. I don't care and neither will the BMW legal department when you try to use your warranty after tracking the car. I don't think relying on PR material is going to win anything against a legal document such as a warranty.

If you are an actual engineer then you should know better than to rely on PR materials for reliability.

Here is my original statement:

Originally Posted by wrsbmw

Of course this is also why you will wear out your car quickly by tracking it. Same thing happens in the engine. All of the moving components are affected similarly and the energy is mostly dissipated as heat. This is also why you shouldn't really race a stock car. It's not built or designed to handle the kinds of prolonged heat that the constant changing from high to low speed on a track will produce.

I know people do it but I also think they do it with a second car, not their regular car. Right?

I said you would wear out your car quickly by tracking it. Nothing wrong with that.

I said most of the energy is dissipated as heat. Nothing wrong with that.

I said you really shouldn't race a stock car. BMW warranty explicitly agrees with me.

I said it's not built or designed to handle the kinds of prolonged heat that the constant changing from high to low speed on a track will produce.

I believe this to be a true statement because a race is tracking of a prolonged nature and BMW voids the warranty under those conditions. You have chosen to avoid dealing with the heat issue here. That is what I originally pointed out was the risk involved. You have consistently pointed to other design features not related to the heat. Of course elevated temperatures are the thing that cause the most failures in mechanical systems and in electrical systems. So that is why I mention that. If you are an engineer, then you should understand my original statement and give it a pass. Instead, you seem to be a lawyer because your response is one of a lawyer.

I never said you couldn't use the car for tracking. I just parsed what I said and really, it's not incorrect at all.

I like the car in the video but it's not stock, it was modded for tracking. I see nothing wrong with tracking the car if you have the bucks to do it. I also said that I thought most people would do it with a second car and put a question mark after the statement.

I wasn't trying to start a fight or an argument in my original post. Just making some observations that I believe are accurate, factual and correct.

[Boss330]

Originally Posted by wrsbmw

Obviously you wanted to nitpick my original statement and start an argument. Looks to me like you got nowhere. Tracking your car is considered improper use I am fairly certain. The warranty is voided if you race the car, that much is very clear.

PR is marketing material and nothing more. You can cut and paste all the statements you want about the car. Sure, put it on the track, ruin it. I don't care and neither will the BMW legal department when you try to use your warranty after tracking the car. I don't think relying on PR material is going to win anything against a legal document such as a warranty.

If you are an actual engineer then you should know better than to rely on PR materials for reliability.

Here is my original statement:



I said you would wear out your car quickly by tracking it. Nothing wrong with that.

I said most of the energy is dissipated as heat. Nothing wrong with that.

I said you really shouldn't race a stock car. BMW warranty explicitly agrees with me.

I said it's not built or designed to handle the kinds of prolonged heat that the constant changing from high to low speed on a track will produce.

I believe this to be a true statement because a race is tracking of a prolonged nature and BMW voids the warranty under those conditions. You have chosen to avoid dealing with the heat issue here. That is what I originally pointed out was the risk involved. You have consistently pointed to other design features not related to the heat. Of course elevated temperatures are the thing that cause the most failures in mechanical systems and in electrical systems. So that is why I mention that. If you are an engineer, then you should understand my original statement and give it a pass. Instead, you seem to be a lawyer because your response is one of a lawyer.

I never said you couldn't use the car for tracking. I just parsed what I said and really, it's not incorrect at all.

I like the car in the video but it's not stock, it was modded for tracking. I see nothing wrong with tracking the car if you have the bucks to do it. I also said that I thought most people would do it with a second car and put a question mark after the statement.

I wasn't trying to start a fight or an argument in my original post. Just making some observations that I believe are accurate, factual and correct.

Looks to me like you were proven wrong actually

I have never questioned that track use will increase wear, in fact I even pointed that out. But again that was never my point. Just as I never debated warranty issues either. Warranty is something you brought up and is also unrelated to wether the engine etc. was designed for track use. I just didn't understand how you could say the M5's engine etc wasn't designed for track use. Especially when BMW themselves say that the M5 is designed for track use. And track days and racing are two different things.

How come you start arguing on other subjects than what the issue is about? Like warranty or wear? You said the car wasn't designed for track use. Wether I track my car and ruin it is a totally unrelated question, as that is my choice. Wether warranty covers track use in litigation happy USA is also a different matter. I have never questioned any of those issues at all.

You might question wether I'm an engineer. That doesn't bother me at all I also work with legal issues daily, so not troubled by having knowledge of legal issues as well.

It seems like you don't realize that in Germany, M5's are repeatedly and prolonged used every day on the Autobahn at speeds over 250km/h. Until you have tried that you probably won't realize that it's very different from driving on 65MPH Highways or Interstates.

The M5 has undergone extensive testing on the Nürburgring. One of the hardest tracks in the world.

Since you are concerned about heat:

Added to which, the engine has an extremely powerful cooling system. This is a combination without parallel worldwide and produces the suitably exclusive performance characteristics you would expect from a BMW M car.

The M5 engine has 4 additional electric water pumps to increase cooling. This includes a separate electric water pump that flows water through the turbos and can be operative up to 30 minutes after engine is switched off.

The oil system is also modified to include oil spray nozzles that cool the piston crowns.

In fact, designing a high performance car not capable to deal with the forces and stresses of driving under similar circumstances as on a track would be the same as designing a car not being able to use it's potential without failure occuring... What you are saying is basically that the car/engine etc is able to generate such amounts of energy that it will selfdestruct at any time if that potential is exploited. (And again: Yes, I do realize that driving at 300km/h on the Autobahn or hard on a track is more stressful and increases wear compared to driving back and forth to work at 65MPH on the Highway)

The M5 'Ring Taxi are bone stock M5's apart from racing brake pads (before the CCB option). They race around the Nürburgring week after week on the worlds supposedly hardest race track, with passengers. If that doesn't generate heat, then what does?

But to sum up:

You say the engine etc. in the M5 wasn't designed for track use.
BMW say in their official information that it was designed for track use.

Wether warranty covers racing etc, and that hard use increase wear is a different question.

I choose to side with BMW on this matter and still believe that the M5 is designed to be used on the track as well as on the street

With that I "include myself out" of this debate

[wrsbmw]

Originally Posted by Boss330

I just didn't understand how you could say the M5's engine etc wasn't designed for track use

I didn't say that and apparently after this long thread you can't read what I originally wrote. Yet you keep repeating what you claim I said when it's not what I said.

There is no debate here, you are simply making a fool of yourself by proving you wanted to nitpick my original statement. You either don't want to read it or you are not bright enough to understand the import of the original statement. You don't seem to understand the meaning of the word prolonged. You also don't seem to understand the difference between racing and a couple of times around the track. I made my original statement abundantly clear. Instead, you make things up such as this.

Originally Posted by Boss330

What you are saying is basically that the car/engine etc is able to generate such amounts of energy that it will selfdestruct at any time if that potential is exploited.

I did not say this. You did. You won't find any such statement on my part. Apparently you wanted an argument, you couldn't get one but you created one instead. Now you are bowing out of the argument after making up new statements I didn't make. I don't know what your point is unless it is to make up a straw man and beat it up. You haven't actually disagreed with anything I said, you have simply made up stuff you claim I said. In addition, nothing I said isn't factual, correct or accurate. Given that, I can't understand your reason for continuing with your senseless posting.

[Boss330]

Originally Posted by wrsbmw

I didn't say that and apparently after this long thread you can't read what I originally wrote. Yet you keep repeating what you claim I said when it's not what I said.

There is no debate here, you are simply making a fool of yourself by proving you wanted to nitpick my original statement. You either don't want to read it or you are not bright enough to understand the import of the original statement. You don't seem to understand the meaning of the word prolonged. You also don't seem to understand the difference between racing and a couple of times around the track. I made my original statement abundantly clear.

Not sure who is the fool The one who doesn't want to take aboard what BMW themselves say about the M5 and what BMW themselves promote and use the M5 for. Or the one who just says what BMW themselves say and do. Track use!

I have pointed out above that racing and a track use is two different things. And that what we are talking about is track use (like a track day), even though the 'Ring Taxi is used hour after hour, week after week on the Nürburgring.

Please read my posts

So, where am I repeating something you didn't say?

Originally Posted by wrsbmw

Of course this is also why you will wear out your car quickly by tracking it. Same thing happens in the engine. All of the moving components are affected similarly and the energy is mostly dissipated as heat. This is also why you shouldn't really race a stock car. It's not built or designed to handle the kinds of prolonged heat that the constant changing from high to low speed on a track will produce.

The thread is about a M5 in the M5 forum. You state a stock car isn't built or designed to cope with track use. Are you know saying that this isn't correct anymore, and that when you said tracking in your original post you really meant tracking for a prolonged period of time, also known as racing?

And excuse me if I didn't understand properly. English is my second language.

[Boss330]

Originally Posted by wrsbmw

I did not say this. You did. You won't find any such statement on my part. Apparently you wanted an argument, you couldn't get one but you created one instead. Now you are bowing out of the argument after making up new statements I didn't make. I don't know what your point is unless it is to make up a straw man and beat it up. You haven't actually disagreed with anything I said, you have simply made up stuff you claim I said. In addition, nothing I said isn't factual, correct or accurate. Given that, I can't understand your reason for continuing with your senseless posting.

You clearly misunderstood me then. I didn't mean to say you had said that, but that what you said amounts to this. Because if the M5 isn't able to withstand the prolonged heat that the engine produces while driving at full power (all 560HP) on the Autobahn, or while going up an Alpine pass in Europe, then it wouldn't cope with track use either (not racing).

[wrsbmw]

Originally Posted by Boss330

You clearly misunderstood me then. I didn't mean to say you had said that, but that what you said amounts to this. Because if the M5 isn't able to withstand the prolonged heat that the engine produces while driving at full power (all 560HP) on the Autobahn, or while going up an Alpine pass in Europe, then it wouldn't cope with track use either (not racing).

Here is what I originally wrote, one more time and it doesn't amount to what you inferred.

Originally Posted by wrsbmw

Of course this is also why you will wear out your car quickly by tracking it. Same thing happens in the engine. All of the moving components are affected similarly and the energy is mostly dissipated as heat. This is also why you shouldn't really race a stock car. It's not built or designed to handle the kinds of prolonged heat that the constant changing from high to low speed on a track will produce.

I know people do it but I also think they do it with a second car, not their regular car. Right?

1.) The car will wear out quickly by tracking it.

The statement implies continuation of the action, not a single event.

I thought I expanded on the idea when I said you shouldn't race a stock car and then made clear the issue was prolonged heat in a race.

I think you are implying that running the car for prolonged periods at it's operational extremes isn't a problem and that it's normal. I disagree. When you have an operational extreme, it is an extreme. The high end of the tach isn't the place for the engine to be operating on a regular basis. If you are an automotive engineer you know this and you know that reliability suffers as a result. This is what I was suggesting and I think I made that pretty clear in my subsequent posts. I even gave good physics based explanations for the laymen on the thread. You somehow still didn't catch my drift but that doesn't mean I didn't communicate clearly because at least one other poster did understand my statement.

I even clarified my statement with the suggestion/question that most people would use a second car for tracking, not their everyday car. I sure didn't spend $100k on my car to ruin it by running it too hard. I enjoy accelerating hard and driving it at high speed but I will be careful with it. This car generates tremendous heat just driving around town, way more than my 535 did.

I am not sure what your point to other owners is. If it's that you can run your car on the track without worry because BMW designed it for that, then I would suggest you are misleading them.

I am sure you can take your car out to the track and run it hard for a few laps. I don't know what a typical tracking experience amounts to but more than a few laps is inadvisable, at least in the way these people that post videos are running their cars. If you do it repeatedly, expect a major engine failure or transmission failure or both at some point. It's not like these cars have a very high reliability rating anyway. This stuff just makes it worse.

[Boss330]

Originally Posted by wrsbmw

You have consistently pointed to other design features not related to the heat. Of course elevated temperatures are the thing that cause the most failures in mechanical systems and in electrical systems. So that is why I mention that.

Heat issues was quoted in the post previous to your post as well.