MDM and melted front right brake pad :(

[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.

Update on Mar 16: After changing the pads and other repairs, turned out both my front brakes were gone. Although the left ones did not fall off or melt, they were completely cracked. Safe to say that both front brakes took the same beating. Therefore, lets assume MDM didn't cause any damage. It was just me being an idiot tracking on stock pads.

/*****************************/

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.

[Estoril Blue]

Did you have an Instructor?

[Groundpilot]

In regards to 1, you should never overdrive the car, regardless what system is on or off.
In regards to 2, noone should be driving on a race track with stock brake pads and fluid.

[zcchen]

I 'overdrive' because I was overly reliant on MDM. It gave me a false sense of security. I never overdrive my track car even when competing in NASA TT events. Maybe I was giving the modern electronics in the M3, my daily, too much respect. Knowing what I know now, I would definitely track it with upgraded fluid, pads and even proper brake duct. Just so that I don't endanger myself and others around me on track.

[zcchen]

One of the main points of my post is about how mdm could work against you.

[Groundpilot]

MDM can work against you or save your butt. It all depends how you use it.
I like to drive with tc off completely, but there are some tracks over here with almost no run off areas, i like to use mdm there sometimes. And when i use it, i try to drive like its off, and its not as intrusive as many ppl think.

[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.

[okusa]

Originally Posted by zcchen

I 'overdrive' because I was overly reliant on MDM. It gave me a false sense of security. I never overdrive my track car even when competing in NASA TT events. Maybe I was giving the modern electronics in the M3, my daily, too much respect. Knowing what I know now, I would definitely track it with upgraded fluid, pads and even proper brake duct. Just so that I don't endanger myself and others around me on track.

What times were you running?

[1MOREMOD]

Stock pads are a liability. You are probably a little faster now also, but I too over used mdm specifically in the rain. I was always fast and it wasn't me doing it.

[zcchen]

I ran 2:04 with a passenger this weekend. I ran 2:03 last time. The reason I ran with MDM is because I was so pleased with the technology.. It does most of the things I do manually when I drive my Z3M with hardly any electronic nannies!

[zcchen]

The guy in Texas with black m3 hooked up a motec datalogger and found out sth still grabbed individual wheel even with everything off.. He has a thread on here..

[zcchen]

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.

Hmm.. Thanks for pointing out that it's me overdriving left turns rather than right turns. Frankly, the M3 is too powerful for me to push it now. I definitely need a ride in an M3 driven by a competent driver to learn.

[jphughan]

Originally Posted by zcchen

Hmm.. Thanks for pointing out that it's me overdriving left turns rather than right turns. Frankly, the M3 is too powerful for me to push it now. I definitely need a ride in an M3 driven by a competent driver to learn.

Well you could have been overdriving everywhere; the wear just indicates that left turns had to be corrected more often and/or more drastically.

Originally Posted by zcchen

The guy in Texas with black m3 hooked up a motec datalogger and found out sth still grabbed individual wheel even with everything off.. He has a thread on here..

Interesting. Link?

[aus]

Originally Posted by zcchen

I ran 2:04 with a passenger this weekend. I ran 2:03 last time. The reason I ran with MDM is because I was so pleased with the technology.. It does most of the things I do manually when I drive my Z3M with hardly any electronic nannies!

Why would you want to drive knowing you're using the technology to do the driving for your?

Originally Posted by zcchen

The guy in Texas with black m3 hooked up a motec datalogger and found out sth still grabbed individual wheel even with everything off.. He has a thread on here..

I'm thinking he's talking about the thread that shows MDM hitting the brakes, but the light now lighting up. I KNOW you WILL spin with MDM off if you over drive the car. Embarrased to say how I know.

.

[Sebringjetta]

Originally Posted by Groundpilot

In regards to 1, you should never overdrive the car, regardless what system is on or off.
In regards to 2, noone should be driving on a race track with stock brake pads and fluid.

[zcchen]

Maybe I didn't get my points across clearly. Judging by my lap time and result from my NASA time trial competition in my z3m, I don't consider myself a novice who can't drive and have to rely on the car electronics to get around the track. Instead, just as I opted for DCT and I'm pushing Bilstein USA to stock EDC Damptronic PSS10, I embrace new technologies! Prior to this event, I had thought MDM is very powerful and clever. Indeed I still believe it will help almost anyone improve their time. However, using the MDM too aggressively, which I did, could cause trouble. In my case it melted the pads in one corner; in your case, maybe less severe, it could cause uneven pad wear.
/****/
Another point I wanted to make is that don't upgrade brake fluid on our cars before upgrading brake pads! The fade resulting from boiling stock fluid is more progressive, while the stock pads fade less progressively.

[slicer]

I'm not trying to be critical here but I don't understand your logic. I do believe that I understand what you are saying but I would look at it differently.

1 - You have learned first-hand that your brakes are not up to the task for track use. I think we can all agree that the M3's brakes are the weakest link.

2 - You have learned that you MDM has been kicking-in and protecting you from losing control of your car - at the expense of your front brakes. That seems like a good thing to me. My goal is to have fun at the track while avoiding damage to my car. Having MDM there to help preserve the car; while still allowing lots of fun is a win/win in my book.

[LiM3y]

Originally Posted by 1MOREMOD

Stock pads are a liability. You are probably a little faster now also, but I too over used mdm specifically in the rain. I was always fast and it wasn't me doing it.

I think there is a difference between a weakness and a liability. Don't want to spread misinformation.

I haven't read a thread where the brakes caused a catastrophic failure, even when they were melted down by that Belgian nutter that ended up stabbing someone.

[mid-corner fun]

Originally Posted by zcchen

Maybe I didn't get my points across clearly. Judging by my lap time and result from my NASA time trial competition in my z3m, I don't consider myself a novice who can't drive and have to rely on the car electronics to get around the track. Instead, just as I opted for DCT and I'm pushing Bilstein USA to stock EDC Damptronic PSS10, I embrace new technologies!

I'm really baffled as to why you would attempt to use stock pads on any track car based on your own comments and admission of running in TT...Perhaps I'm missing something here.

[zcchen]

Originally Posted by slicer

I'm not trying to be critical here but I don't understand your logic. I do believe that I understand what you are saying but I would look at it differently.

1 - You have learned first-hand that your brakes are not up to the task for track use. I think we can all agree that the M3's brakes are the weakest link.

2 - You have learned that you MDM has been kicking-in and protecting you from losing control of your car - at the expense of your front brakes. That seems like a good thing to me. My goal is to have fun at the track while avoiding damage to my car. Having MDM there to help preserve the car; while still allowing lots of fun is a win/win in my book.

My logic is quite simple:
1, either run completely stock or upgrade the brake system as a whole;
2, don't rely on MDM to go fast. In my case, I didn't need the MDM to save me, I could've saved myself; I used MDM to push harder.

[1MOREMOD]

Originally Posted by LiM3y

I think there is a difference between a weakness and a liability. Don't want to spread misinformation.

I haven't read a thread where the brakes caused a catastrophic failure, even when they were melted down by that Belgian nutter that ended up stabbing someone.

Probably wrong word was used. Think anyone who runs time trials would know not to push stock pads very hard.

[1MOREMOD]

Originally Posted by zcchen

My logic is quite simple:
1, either run completely stock or upgrade the brake system as a whole;
2, don't rely on MDM to go fast. In my case, I didn't need the MDM to save me, I could've saved myself; I used MDM to push harder.

If your a fast driver mdm would be an interference not help you go faster.