MDM and melted front right brake pad :(

[dogbone]

Here's the thread from Ti-Jean:

http://www.m3post.com/forums/showthread.php?t=821800

It's interesting to watch how the brakes are activated on each wheel in his videos.

[S65 Underdog]

Originally Posted by zcchen

To all fellow E9X M3 owners, I have learned a lesson about our cars this past weekend at Buttonwillow, one specifically regarding the Euro MDM and front brakes.

In short, I overly relied on MDM, thus 'over-driven' the car, therefore melted my front right brake pads, front right alone.

I drive a 2011 E90 M3 ZCP with DCT. Only mods are BMC intake filter, cat delete, 275/285 RS3 tires and Motul RBF600 Brake fluid. It has stock ZCP suspension and stock brake pads. It is this car's third track day. First time it was completely stock; second time it had the same setup as now except stock brake fluid instead of the RBF600. I had tremendous fun without melting any brake pads driving the car during the first two times out even though there was significant brake fade.

In preparations to the track day this past weekend, I flushed the brake with RBF600, hoping to reduce the amount of brake fade. On the track, I did notice a slight improvement. However, having better fluid turned the stock pads into the weakest link under heat. Also, running stickier and wider tires than stock ones also caused the brakes to work harder. Finally, the party piece, the MDM brakes each individual wheel to help rotate the car when kicking in. I did not know this information until after the incident. I have always run track days in Euro MDM mode since I thought it allows fun without me having to worry about spinning out. It did work quite well helping me get around the corners, especially 'Riverside'(a high speed, 100+mph, right hand sweeper). I stayed flat through it and a few other corners while I clearly felt the MDM doing its job. In that time, I loved the MDM and thought it was brilliant. Not so much now. I thought the MDM only cut engine power. Therefore I was so reliant on it. Now that I know, I will not drive with MDM at all, track or street since it deceives me to drive harder than the physical limits of the car. In retrospect, I believe that is why I (or actually the MDM) only melted the front right pads while front left seemed okay.

My tentative solution to this:
1, do not overdrive the car... lol..
2, either upgrade pads or downgrade fluid

In regards to 1, I plan on turning off the traction control so that I stay more alert and not push the car so hard around corners. From internet research, it seems like the computers would still brake the inside wheels even if the traction control is 'completely' off.

I was only aware that with MDM on your car only engages independent braking and engine cutout when the car has hit certain angles? Do you have Euro MDM? If not get it, the difference is night and day.

If you are pushing your MDM to the point that the car has to constantly interfere then you are not driving the car properly and smoothly when an oversteer occurs (this is really the only time it will fully engage to save your butt). Please get an instructor and or just start going slower and focus on your driving a bit more before focusing on your time.

The last thing you should be doing is driving with DSC OFF. You are being shown by the car that you are not ready for this because the car is having to do the work for you. Your braking system will only kick in when the dash signals the traction symbol on the dash. Other then that you are driving the car yourself. I hope this makes sense. Your best bet is to get EURO MDM and work on your rhythm and reaction time to oversteer. If you can't correct it before MDM then you driving DSC OFF will be a nightmare.

[S65 Underdog]

Originally Posted by jphughan

Right front brake pad means it was correcting a lot of impending oversteer on left-hand turns, so it was preventing rotation in your case, not helping it (which would have manifested as excessive wear on a rear pad). Hopefully that helps you figure out where you're overdriving. The flashing light should too. Oh, and the instructor.

MDM is a great learning tool as long as you pay attention to when and how it intervenes so you can adapt your driving technique accordingly. If you just use it to continue driving like you do now, it's nothing more than a crutch and enabler of bad habits. I wouldn't turn it off until you've figured out what you're doing wrong, or you might learn that lesson in a far harsher manner. If you feel it intervening, that should not be cause for marveling at its awesomeness (except as a thank you for saving you), but rather a wake-up call for you. Especially if you have Euro MDM, you should absolutely be able to drive very near to the car's limits without ever seeing the flashing light if you're driving properly, so that should be your goal, not turning it off and just playing it safer. You can play it safer with it still on.

I personally have Euro MDM and keep it on because my car is still worth a fair amount, so I appreciate the extra safety net. Of the relatively few occasions it's stepped in, about half were times when I probably would have been ok without it and the other half were definitely because I had made a mistake and was grateful for the assistance.

And yep, pretty much every reasonably modern stability control system works by braking individual wheels. But where are you reading that the car brakes the inside wheels even with everything off? The regular series (non-M) cars do that regardless of DSC state because they don't have a mechanical LSD, so braking the inside wheel is sort of a substitute (it's a feature called EDLC), but M cars don't have that because we of course do have a mechanical LSD.

+1

[FTS]

Sorry for the silly question, but do I understand correctly that it is not possible to separate stability control and traction control with MDM, so they are either both on or off depending on how you setup MDM?

[radiantm3]

Originally Posted by OC3

Anyhow, all I'm saying is, it's a more fuller experience. That's all.

Amen, brother. Fast laps are fun, but nothing is more fulfilling than feeling in control of the car and knowing it is your skill at work and not a computer. Best feeling ever.

[MasterP]

Originally Posted by FTS

Sorry for the silly question, but do I understand correctly that it is not possible to separate stability control and traction control with MDM, so they are either both on or off depending on how you setup MDM?

That's right.

[CanAutM3]

Originally Posted by S65 Underdog

If you are pushing your MDM to the point that the car has to constantly interfere then you are not driving the car properly and smoothly. Please get an instructor and or just start going slower and focus on your driving a bit more before focusing on your time.

Agree thus far

Originally Posted by S65 Underdog

The last thing you should be doing is driving with DSC OFF. You are being shown by the car that you are not ready for this because the car is having to do the work for you.

IMO, unless you turn off MDM, you will not learn what you are doing wrong.

Originally Posted by S65 Underdog

Your braking system will only kick in when the dash signals the traction symbol on the dash.

From my experience, I can feel DSC/MDM doing small/quick interventions without flashing the light in the cluster. So relying on the light is not a good indicator. Further, the eyes need to be on the track, not the cluster

Originally Posted by S65 Underdog

Other then that you are driving the car yourself. I hope this makes sense. Your best bet is to get EURO MDM and work on your rhythm and reaction time to oversteer. If you can't correct it before MDM then you driving DSC OFF will be a nightmare.

As soon as a beginner student has acquired the basic track driving skills and that the pace is decent enough to play with the balance of the car, I recommend turning off the aids. Otherwise the bad habits start to form. And trust me, once acquired, those bad habits are tough to get rid of. I had to work very hard with several students to rid them of those nasty habits.

I want to stress that driving without aids remains riskier and should always be at the discretion of the student. I have sometimes forced some students to "turn on" the aids but never the opposite.

[S65 Underdog]

I have replied to your comments in red (not anger, just color).

Originally Posted by CanAutM3

IMO, unless you turn off MDM, you will not learn what you are doing wrong.

This is not accurate. I personally first started at the Nurburgring with DSC ON. I came to realize the car is far too intrusive without it so that lasted about a day. I then started to activate MDM to allow the car to play more. I will most likely never go DSC OFF at the Nurburgring, the room for error is too small and its a challenging track. I will say I have improved from using Euro MDM at the Ring, it has allowed my car to loss traction and allow me to correct it before the car does so, not saying I always beat the DSC to it but most of the time I do. I know plenty of skilled drivers that use MDM for tracking at a fast pace. You just need to know what you have done wrong that causes the DSC to activate. From there you can work on your mistakes say on an airfield or drifting event. Please don't go around telling people that MDM won't help you be a better driver. You just need to understand what it's doing and why it's doing it.

From my experience, I can feel DSC/MDM doing small/quick interventions without flashing the light in the cluster. So relying on the light is not a good indicator. Further, the eyes need to be on the track, not the cluster

I am amazed that you can feel DSC kick in during the small/quick interventions, you must really be one with your car being that DSC only activates abruptly when you have hit a certain slip angle (oversteer). Other then that I have to say its impossible to "feel" the DSC activated otherwise. Also, I am not stating to stare at your cluster but its fairly easy for me to see when I am driving.....from my experience of course.


As soon as a beginner student has acquired the basic track driving skills and that the pace is decent enough to play with the balance of the car, I recommend turning off the aids. Otherwise the bad habits start to form. And trust me, once acquired, those bad habits are tough to get rid of. I had to work very hard with several students to rid them of those nasty habits.

I am not sure what kind of instructor you are but a professional one wouldn't give this kind of advice to people on a website not fully knowing the drivers abilities. This of course would depend on the skill of the driver, the room for error allowed at his track or practice area and your over all feeling with the driver.


I want to stress that driving without aids remains riskier and should always be at the discretion of the student. I have sometimes forced some students to "turn on" the aids but never the opposite.

Nice disclaimer but I feel like you are contradicting the third section of your quote about DSC.

[bigjae1976]

Originally Posted by S65 Underdog

I have replied to your comments in red (not anger, just color).

I am in 100% agreement with CanAutM3 despite him being Canadian.

Recommending and demanding are two different things. There is a liability issue with telling someone to turn off traction control.

The problem with MDM is the mindset. You will lose the fear or over time, you develop the comfort with not being forced to stay ahead of the car. I've seen it all to often. A high intermediate student turns off traction control and then has a terrible weekend full of spins and offs.

DSC measures wheel spin and yaw (slip angle). Euro MDM does not allow the tires (r-comps especially) to achieve an optimum amount of slip or ever really slide the car.

Really fast drivers? Or really fast cars? I'll agree with the statement that there are a lot of drivers with really fast cars that go fast with DSC on. The simple fact is that the fastest way around any track will involve a small slide or some aggressive slip angle in some or all corners.

The E9X M3 traction control system is not super advanced. Some advanced traction control systems can improve speed of an inept driver. Just like ABS does. But the computers aren't there.

[S65 Underdog]

Originally Posted by bigjae1976

I am in 100% agreement with CanAutM3 despite him being Canadian.

Recommending and demanding are two different things. There is a liability issue with telling someone to turn off traction control.

The problem with MDM is the mindset. You will lose the fear or over time, you develop the comfort with not being forced to stay ahead of the car. I've seen it all to often. A high intermediate student turns off traction control and then has a terrible weekend full of spins and offs.

DSC measures wheel spin and yaw (slip angle). Euro MDM does not allow the tires (r-comps especially) to achieve an optimum amount of slip or ever really slide the car.

Really fast drivers? Or really fast cars? I'll agree with the statement that there are a lot of drivers with really fast cars that go fast with DSC on. The simple fact is that the fastest way around any track will involve a small slide or some aggressive slip angle in some or all corners.

The E9X M3 traction control system is not super advanced. Some advanced traction control systems can improve speed of an inept driver. Just like ABS does. But the computers aren't there.

I for one have never lost fear even using MDM. People who do so should stop driving these kind of cars.

MDM allows you to achieve a small slide or some aggressive slip angle. I am not sure what type of MDM you are using but its an impressive system. You just have to be in control of the car and understand the car to really reap from its benefit when the time comes that you made the simple mistake that could cost you your life or your car. Try this for me, take your car out on a turn with MDM on.....make quick jerky corrections when the oversteer engages. Now take the same turn but ease into the oversteer and smoothly return the car straight. You will notice a huge difference between DSC doing the work and you doing the work. Maybe this is the OP's problem.

This is what I am trying to get at. I have tested this myself and seen and felt the difference. I agree that MDM can blind bad habits but what I have been trying to say is that if you understand what you are doing when the bad habits arise you are in understanding of what needs to be done to correct it (less gas/more gas/amount of oversteer correction required) without having the DSC take over. Also, by having R-compounds you are technically reducing wheel spin because there is more traction to the ground thus the MDM system thinks you are in better control thus not interfering as much. Now if you had winter tires on your car for the track your wheel spin would be out of control and MDM would engage much more often. Does this make sense? I hope it does because I have tested this as well last winter. Insane interference from DSC.

One last thing, I would think that all of us here are not paid large amounts of money to race cars but that we are doing it for fun. I never plan to become some overly paid hot shot racer.......... I do it for fun. Understanding and knowing your car while using MDM or not using it is important we can all agree, but using MDM is a safety net that we should all use unless you have the money to buy two M3's or you are a true professional. Will I use DSC OFF sometime in my life? I sure will but it will be after I have had enough experience and or when the margin for error is better in my favor (track run off)


If you don't believe me check out my video below and you can hear my PSS tires screaming from the sliding and wheel spin that MDM allows. You can also see two sections (Wehrseifen and Steilstreke) where I make corrects to the car before the DSC can engage. I know that I made the corrections before the car because you can tell a difference when the car is doing the work and you are.

[CanAutM3]

Originally Posted by S65 Underdog

I have replied to your comments in red (not anger, just color).

Have a look at Ti-Jean's video. It is quite obvious that even Euro MDM interferes much more than one would believe. If you watch his second video, where he drives with DSC off, it is clear that he has good car control and doesn't overdrive the car. Yet, in the first video, MDM applies the front outside brake in situations that it believes could LEAD to an oversteer. This can be felt as a very light tug on the steering wheel. Further, when trying to tighten the cornering line with quick lifts of the throttle, MDM will prevent it and the car keeps understeering. If you have a good feel for your car, you will perceive these interventions.

Also, even Euro MDM has a much lower slip threshold at higher speeds. Driving in the snow at low speeds, I can sometimes hardly believe the crazy angles Euro MDM allows me to get away with. Yet, at much higher speeds on a dry track, I can feel that annoying tugging where it is really not needed.

Regarding tire grip, you analogies are incorrect. You probably are not feeling MDM with R-comps because you are still far from getting decent slip angles out of them. Because of the higher grip, you need to be that much faster to near their limits.

I am an instructor that promotes good car control way above posting fast lap times. Car control is what makes a driver a safe one. However, one also needs to realize that turning off the aids does increase the level of risk involved. If MDM is used as safety net, that is perfectly fine. But, IMO, one still needs to know how to drive without it. I also use MDM on occasions in specific conditions. I definitely would use it on the 'ring, with its ever changing conditions, and would not switch it off until I have a significant amounts of laps under my belt.

What I condone is drivers that "RELY" on MDM to go fast. The ones that don't have good car control and use MDM to hide their mistakes. Those are the dangerous ones that get bitten when they switch the aids off.

[S65 Underdog]

Originally Posted by CanAutM3

Have a look at Ti-Jean's video. It is quite obvious that even Euro MDM interferes much more than one would believe. If you watch his second video, where he drives with DSC off, it is clear that he has good car control and doesn't overdrive the car. Yet, in the first video, MDM applies the front outside brake in situations that it believes could LEAD to an oversteer. This can be felt as a very light tug on the steering wheel. Further, when trying to tighten the cornering line with quick lifts of the throttle, MDM will prevent it and the car keeps understeering. If you have a good feel for your car, you will perceive these interventions.

Also, even Euro MDM has a much lower slip threshold at higher speeds. Driving in the snow at low speeds, I can sometimes hardly believe the crazy angles Euro MDM allows me to get away with. Yet, at much higher speeds on a dry track, I can feel that annoying tugging where it is really not needed.

Regarding tire grip, you analogies are incorrect. You probably are not feeling MDM with R-comps because you are still far from getting decent slip angles out of them. Because of the higher grip, you need to be that much faster to near their limits.

I am an instructor that promotes good car control way above posting fast lap times. Car control is what makes a driver a safe one. However, one also needs to realize that turning off the aids does increase the level of risk involved. If MDM is used as safety net, that is perfectly fine. But, IMO, one still needs to know how to drive without it. I also use MDM on occasions in specific conditions. I definitely would use it on the 'ring, with its ever changing conditions, and would not switch it off until I have a significant amounts of laps under my belt.

What I condone is drivers that "RELY" on MDM to go fast. The ones that don't have good car control and use MDM to hide their mistakes. Those are the dangerous ones that get bitten when they switch the aids off.

I have watched the videos and to be honest with you the corrections that the car is making make absolutely no difference. If you would have realized what I was getting at from the begging then I wouldn't have to be wasting my time with you on debating over this. You personally have taken one persons opinion and started a debate over it because you are the greatest instructor ever to walk the face of this earth and for some reason enjoy having d*ick swinging contest on the forum.

I am not just about posting fast video times, posting your videos helps to allow others to see and learn from it. If you can't agree on this then you are outright insane. If you would like to debate about this any further feel free to PM me. You obviously don't agree with me and I am fed up with you and your amazing instructor skills.

For you to come into a thread I created and attack me is immature and pitiful. I am trying to start a thread that is focused on having only videos of our cars on the track. How about you post a video that is creditable other then your pointless .02 cents that means nothing to me in my thread.

[TheKosherStogie]

Originally Posted by CanAutM3

Have a look at Ti-Jean's video. It is quite obvious that even Euro MDM interferes much more than one would believe. If you watch his second video, where he drives with DSC off, it is clear that he has good car control and doesn't overdrive the car. Yet, in the first video, MDM applies the front outside brake in situations that it believes could LEAD to an oversteer. This can be felt as a very light tug on the steering wheel. Further, when trying to tighten the cornering line with quick lifts of the throttle, MDM will prevent it and the car keeps understeering. If you have a good feel for your car, you will perceive these interventions.

Also, even Euro MDM has a much lower slip threshold at higher speeds. Driving in the snow at low speeds, I can sometimes hardly believe the crazy angles Euro MDM allows me to get away with. Yet, at much higher speeds on a dry track, I can feel that annoying tugging where it is really not needed.

Regarding tire grip, you analogies are incorrect. You probably are not feeling MDM with R-comps because you are still far from getting decent slip angles out of them. Because of the higher grip, you need to be that much faster to near their limits.

I am an instructor that promotes good car control way above posting fast lap times. Car control is what makes a driver a safe one. However, one also needs to realize that turning off the aids does increase the level of risk involved. If MDM is used as safety net, that is perfectly fine. But, IMO, one still needs to know how to drive without it. I also use MDM on occasions in specific conditions. I definitely would use it on the 'ring, with its ever changing conditions, and would not switch it off until I have a significant amounts of laps under my belt.

What I condone is drivers that "RELY" on MDM to go fast. The ones that don't have good car control and use MDM to hide their mistakes. Those are the dangerous ones that get bitten when they switch the aids off.

^+1

BMW system isn't advance enough and doesn't allow enough slip angle. You can still go fast with MDM on as DogBone has proved. But you won't get 100% out of the car.

[bigjae1976]

Originally Posted by S65 Underdog

I for one have never lost fear even using MDM. People who do so should stop driving these kind of cars.

I'm not scared of my E90 M3 on the track. I slide the shit out of mine. So I need to stop driving my car? Fear is what leads to bad decisions and indecisiveness. The confidence you have by being connected with the car (read no DSC) and that you and only you control the car...that leads to building advanced skills and ultimately why we drive on a track...more speed.

That's why I drive on the track. To go fast. Going slow is not fun.

Originally Posted by S65 Underdog

Try this for me, take your car out on a turn with MDM on.....make quick jerky corrections when the oversteer engages. Now take the same turn but ease into the oversteer and smoothly return the car straight. You will notice a huge difference between DSC doing the work and you doing the work.

I do think that MDM can be a good learning tool by providing some feedback. But why use computer generated feedback when there's plenty of feedback in the steering wheel, seats, dead pedal, brake pedal and gas pedal. Not to mention using your sight and hearing. See, that's the issue. I've seen it all too often where a student has some form of traction control on and their vision is focused on the hood of the car. I watch a student's head a lot, I've seen these guys drive a whole lap and never look beyond the limits of the pavement in front of them. The ones that have the great vision and are consistent are the ones that are not driving with traction control.

I know what MDM in both forms does. As I've said earlier, MDM IS dangerous in a situation where you want car rotation. MDM is not a revelation...all it does is keep the car going straight. You may not want the car to go straight.

Originally Posted by S65 Underdog

I agree that MDM can blind bad habits but what I have been trying to say is that if you understand what you are doing when the bad habits arise you are in understanding of what needs to be done to correct it (less gas/more gas/amount of oversteer correction required) without having the DSC take over. Also, by having R-compounds you are technically reducing wheel spin because there is more traction to the ground thus the MDM system thinks you are in better control thus not interfering as much. Now if you had winter tires on your car for the track your wheel spin would be out of control and MDM would engage much more often. Does this make sense? I hope it does because I have tested this as well last winter. Insane interference from DSC.

Knowing what needs to be done to correct is one thing. Actually doing it is a whole other ballgame. Its easy to say, "MDM save me, I should have countersteered" vs "the back end is about to come around".

Although this is a E46 M3, it goes to show how MDM really limits your options because you really only have one...which is to slow down. It just started to rain, the track was getting slicker with every lap...and DSC was off...and I was on NT01s. Not street tires. Oh, I was having a LOT of fun.

Originally Posted by CanAutM3

I am an instructor that promotes good car control way above posting fast lap times.

I do wish the DE orgs that I run with would put a little more focus on car control early on. But there is a lack of facilities in most cases but still...

[Brent Dalton]

Originally Posted by bigjae1976

I do wish the DE orgs that I run with would put a little more focus on car control early on. But there is a lack of facilities in most cases but still...

Agree. I've started AutoXing more again to continue to hone car control skills. Also, my M3 is a new platform for me so I would rather find out how the car acts /reacts/responds in a safe parking lot opposed to on a track at significantly higher speeds. Skid pad is an awesome tool. The best DE's I attended early on were the ones with skid pads built in.

[CanAutM3]

Originally Posted by S65 Underdog

I have watched the videos and to be honest with you the corrections that the car is making make absolutely no difference. If you would have realized what I was getting at from the begging then I wouldn't have to be wasting my time with you on debating over this. You personally have taken one persons opinion and started a debate over it because you are the greatest instructor ever to walk the face of this earth and for some reason enjoy having d*ick swinging contest on the forum.

I am not just about posting fast video times, posting your videos helps to allow others to see and learn from it. If you can't agree on this then you are outright insane. If you would like to debate about this any further feel free to PM me. You obviously don't agree with me and I am fed up with you and your amazing instructor skills.

For you to come into a thread I created and attack me is immature and pitiful. I am trying to start a thread that is focused on having only videos of our cars on the track. How about you post a video that is creditable other then your pointless .02 cents that means nothing to me in my thread.

You posted an opinion that I did not agree with. I am simply offering a counter point based on my own experiences for the OP and other readers to ponder. My opinion is only one of the 5 billion ones on this earth. If you like it take it, otherwise leave it. Like you, I am on this forum to learn and share my experiences for others to learn. Good constructive debates with good humor in between is what makes this forum so enjoyable .

As for a video, see post #862 here

Now, let's get this thread back on topic

[klammer]

Originally Posted by S65 Underdog

I have watched the videos and to be honest with you the corrections that the car is making make absolutely no difference. If you would have realized what I was getting at from the begging then I wouldn't have to be wasting my time with you on debating over this. You personally have taken one persons opinion and started a debate over it because you are the greatest instructor ever to walk the face of this earth and for some reason enjoy having d*ick swinging contest on the forum.

I am not just about posting fast video times, posting your videos helps to allow others to see and learn from it. If you can't agree on this then you are outright insane. If you would like to debate about this any further feel free to PM me. You obviously don't agree with me and I am fed up with you and your amazing instructor skills.

For you to come into a thread I created and attack me is immature and pitiful. I am trying to start a thread that is focused on having only videos of our cars on the track. How about you post a video that is creditable other then your pointless .02 cents that means nothing to me in my thread.

Wow, let's not get our panties in a bunch. Think its excellent feedback and insight and absolutely NOT antagonistic or confrontational, but you on the other hand...

[zcchen]

UPDATE: !!!!! @@

Turned out I didn't overdrive in terms of MDM ruining my brakes. Although my left front brake looked fine, when I took the right front pads off, they were also completely cracked, on the verge of disintegrating. It is safe to say melting my front right but not left happened completely by chance.

So I was only an idiot driving with stock pads on track. Actually even the rear pads were cracked and all rotors had heat spots beyond repair. By the way, I blew up my front wheel bearings too. What a day it was at track.

Now that I have put on Pagid pads, new rotors, new wheel bearings, and looking to do a whole brake duct set up, I will return to button willow on Apr 12. I will test the MDM then. I will run a hot lap with it on and another with it off. I will make sure to go pro it for you all

[pkimM3r]

Everyone local lets go to brp on the same date