BMW M3 Forum (E90 E92)

BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Track / Autocross / Dragstrip / Driving Techniques
 
GTB Performance
Post Reply
 
Thread Tools Search this Thread
      04-05-2013, 02:34 AM   #23
aus
Major General
 
Drives: Odysse
Join Date: Jul 2005
Location: Seal Beach, CA

Posts: 7,295
iTrader: (5)

Quote:
Originally Posted by admranger View Post
Wow, crazy pad wear given the Endless' reputation for long life. Wow.

Great stuff.

Soooooo, how hard is it to code the euro MDM into the car?
Next time you're in LA or OC, it can be done for $60, and that includes anything else you want coded; like the Accept screen delete, folding mirrors with the door handle or key fob or anything else you may want. It's a flat rate. I haven't checked out the Vegas forums to see if anyone does it there.

Of if you have the time and know computers: bmw coding(one word) dot com

.

And that Nascar 1/2 at AAA definitely gives the regular MDM fits... which makes the rear end wiggle . I haven't tried with Euro MDM yet.

.
__________________
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."

Last edited by aus; 04-05-2013 at 02:43 AM.
aus is offline  
0
Reply With Quote
      04-05-2013, 11:45 AM   #24
The HACK
Garland Operator 7G
 
The HACK's Avatar
 
Drives: 2006 MZ4C, 2013 Veloster Turbo
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day

Posts: 3,391
iTrader: (1)

Quote:
Originally Posted by Ti-Jean View Post
I have KW clubsport suspension with stock swaybars.

I'm always trying to get a picture with a wheel lifted but it seems pretty hard to get. Your theory is still possible though.
The wheel doesn't have to come fully off the track surface for MDM to intervene, IMO. It just needs to be unloaded enough to *almost* spin freely.

I'd set up another camera pointed at the left front wheel, if you're coming to Auto Club Speedway on May 3rd, to see if it's intervening when it's lifting. Set the camera nice and low, on the sideskirt low enough to capture the wheel's hop and see if it brakes when the tire lifts off the ground.
__________________
Quote:
No way I'd ever take my BMW to the track.
Quote:
Then why do you have $3,000 worth of suspension mods on your car?
Quote:
...
-Overheard at the last B****rfest.
The HACK is offline  
0
Reply With Quote
      04-05-2013, 11:55 AM   #25
CanAutM3
Brigadier General
 
CanAutM3's Avatar
 
Drives: 2015 M4 DCT
Join Date: Jan 2012
Location: Montreal

Posts: 3,527
iTrader: (0)

Garage List
2008 BMW M3  [0.00]
2006 Audi S4  [0.00]
Quote:
Originally Posted by The HACK View Post
The wheel doesn't have to come fully off the track surface for MDM to intervene, IMO. It just needs to be unloaded enough to *almost* spin freely.

I'd set up another camera pointed at the left front wheel, if you're coming to Auto Club Speedway on May 3rd, to see if it's intervening when it's lifting. Set the camera nice and low, on the sideskirt low enough to capture the wheel's hop and see if it brakes when the tire lifts off the ground.
I am not sure front wheel lift is what is causing MDM intervention. Watching the video, most of the time it is the front/outside wheel that is being braked. This is consistent with a stability system wanting to correct/prevent and oversteer condition. IMO, a front tire slip would be corrected with a rear/inside wheel brake application.
CanAutM3 is offline   Canada
0
Reply With Quote
      04-05-2013, 12:03 PM   #26
The HACK
Garland Operator 7G
 
The HACK's Avatar
 
Drives: 2006 MZ4C, 2013 Veloster Turbo
Join Date: Oct 2007
Location: Welcome to Jamaica have a nice day

Posts: 3,391
iTrader: (1)

Quote:
Originally Posted by CanAutM3 View Post
I am not sure front wheel lift is what is causing MDM intervention. Watching the video, most of the time it is the front/outside wheel that is being braked. This is consistent with a stability system wanting to correct/prevent and oversteer condition. IMO, a front tire slip would be corrected with a rear/inside wheel brake application.
I'm willing to bet a swift kick in the ss that he's got his brake signals crossed, or the data software is mapping the wrong brakes, left and right.
__________________
Quote:
No way I'd ever take my BMW to the track.
Quote:
Then why do you have $3,000 worth of suspension mods on your car?
Quote:
...
-Overheard at the last B****rfest.
The HACK is offline  
0
Reply With Quote
      04-05-2013, 12:24 PM   #27
CanAutM3
Brigadier General
 
CanAutM3's Avatar
 
Drives: 2015 M4 DCT
Join Date: Jan 2012
Location: Montreal

Posts: 3,527
iTrader: (0)

Garage List
2008 BMW M3  [0.00]
2006 Audi S4  [0.00]
Quote:
Originally Posted by The HACK View Post
I'm willing to bet a swift kick in the ss that he's got his brake signals crossed, or the data software is mapping the wrong brakes, left and right.
So if the front brake signals are crossed, that would imply that MDM is braking the inside front wheel. Now why would a stability system brake the slower rotating wheel (the one that is lifting) ?

I believe that the answer is much simpler. IMO, MDM is simply anticipating a potential oversteer and is applying outside front brake to correct. As was mentioned by Bigjae, a square tire setup would accentuate this type of MDM intervention.
CanAutM3 is offline   Canada
0
Reply With Quote
      04-06-2013, 11:28 PM   #28
admranger
First Lieutenant
 
admranger's Avatar
 
Drives: 2002 M3, 2005 X5, 2011 M3
Join Date: May 2011
Location: Las Vegas

Posts: 364
iTrader: (0)

Quote:
Originally Posted by CanAutM3 View Post
So if the front brake signals are crossed, that would imply that MDM is braking the inside front wheel. Now why would a stability system brake the slower rotating wheel (the one that is lifting) ?

I believe that the answer is much simpler. IMO, MDM is simply anticipating a potential oversteer and is applying outside front brake to correct. As was mentioned by Bigjae, a square tire setup would accentuate this type of MDM intervention.
Agree. NFW it's touching the inside front wheel in a turn. If it were understeering, it would brake the inside rear wheel.
__________________
'11 E90 M3, Mebourne/Black/Fox Red/Black, 6MT, PP2, heated seats, moonroof, split folding rear seats, iPod/USB adapter, Technic harness, JL XD 6/600.
'02 E46M3, Imola/Black, 6MT, CWP, no sunroof, Ohlins, Eibachs, PFC DD rotors, PFC pads! HAT Clarus/Legatia speakers, 2 big amps in the back.
'05 X5 4.4i, Imola/Black, Premium, Cold, HAT Imagine 6.5's, Intravee iPod adapter
admranger is online now  
0
Reply With Quote
      04-06-2013, 11:30 PM   #29
admranger
First Lieutenant
 
admranger's Avatar
 
Drives: 2002 M3, 2005 X5, 2011 M3
Join Date: May 2011
Location: Las Vegas

Posts: 364
iTrader: (0)

Quote:
Originally Posted by aus View Post
Next time you're in LA or OC, it can be done for $60, and that includes anything else you want coded; like the Accept screen delete, folding mirrors with the door handle or key fob or anything else you may want. It's a flat rate. I haven't checked out the Vegas forums to see if anyone does it there.

Of if you have the time and know computers: bmw coding(one word) dot com

.

And that Nascar 1/2 at AAA definitely gives the regular MDM fits... which makes the rear end wiggle . I haven't tried with Euro MDM yet.

.
Thanks. Not sure when I'll be in LA. Restraining order and all that...
__________________
'11 E90 M3, Mebourne/Black/Fox Red/Black, 6MT, PP2, heated seats, moonroof, split folding rear seats, iPod/USB adapter, Technic harness, JL XD 6/600.
'02 E46M3, Imola/Black, 6MT, CWP, no sunroof, Ohlins, Eibachs, PFC DD rotors, PFC pads! HAT Clarus/Legatia speakers, 2 big amps in the back.
'05 X5 4.4i, Imola/Black, Premium, Cold, HAT Imagine 6.5's, Intravee iPod adapter
admranger is online now  
0
Reply With Quote
      04-07-2013, 10:22 PM   #30
kaiv
Major
 
Drives: E92 M3
Join Date: Mar 2010
Location: San Diego, CA

Posts: 1,232
iTrader: (15)

Quote:
Originally Posted by DallasBoosted View Post
People drive on the track in anything but DSC OFF?
Isn't that some ****?

The sad thing about all those new electronics is that it breeds a new generation of drivers that pretty much don't know any better. Hell some defend it. I wonder how people used to do before this stuff existed
kaiv is offline   United_States
0
Reply With Quote
      04-08-2013, 12:31 AM   #31
aus
Major General
 
Drives: Odysse
Join Date: Jul 2005
Location: Seal Beach, CA

Posts: 7,295
iTrader: (5)

I had a ride at AAA with Judy (CCA instructor who works at Crevier) and she said she keeps MDM on and she drives with MDM on and I don't think she knows about the Euro MDM. Ti-Jean did mention it to her in the classroom session and she was not aware of it.
__________________
Let me get this straight... You are swapping out parts designed by some of the top engineers in the world because some guys sponsored by a company told you it's "better??" But when you ask the same guy about tracking, "oh no, I have a kid now" or "I just detailed my car." or "i just got new tires."
aus is offline  
0
Reply With Quote
      04-08-2013, 03:03 AM   #32
OC3
Havin' a blast!
 
OC3's Avatar
 
Drives: 2013 M3 E92 Jerez Blk DCT ZCP
Join Date: Nov 2010
Location: SoCal

Posts: 4,714
iTrader: (1)

Quote:
Originally Posted by kaiv View Post
Quote:
Originally Posted by DallasBoosted View Post
People drive on the track in anything but DSC OFF?
Isn't that some ****?

The sad thing about all those new electronics is that it breeds a new generation of drivers that pretty much don't know any better. Hell some defend it. I wonder how people used to do before this stuff existed
About 6 months before I went DSC off, I had a pretty prolonged argument on this forum with someone who was very insistent that DSC must be off when tracking (even mentioned that it's a must if you want to get a racing license, despite majority of HPDE people not having the interest, time nor the talent to go all the way like that).

Then, the next time I saw him at Buttonwillow, he ran half the day on MDM! wtf?
__________________

BRP CW13 1:58 | CVR CW 2:01 | CVR CCW 2:02 | ACS 1:53 | WSIR 1:34
2013 E92 M3 Jerez Black DCT ZCP | JRZ RS Pro | Brembo BBK | Endless ME20 | Volk TE37 18x10.5 squared | NT01/TD
OC3 is offline   United_States
0
Reply With Quote
      04-08-2013, 06:21 AM   #33
kotik
Lieutenant
 
kotik's Avatar
 
Drives: e90 M3 ESS 575
Join Date: Jun 2011
Location: Germany

Posts: 521
iTrader: (0)

Quote:
Originally Posted by kaiv View Post
Isn't that some ****?

The sad thing about all those new electronics is that it breeds a new generation of drivers that pretty much don't know any better. Hell some defend it. I wonder how people used to do before this stuff existed
F1 cars have a form of MDM, so do Le Mans Cars, so do DTM cars.... there was a vid of DTM driver explaining MDM slip angles. It's not a bad thing to have on a track. Say Nordschleife, you better be rich to run without. Many pro's crash on the ring.

I wish we could program MDM more than euro mdm... I think US is 4% slip vs Euro is 7% slip. Wish we could do like 10-11%... I just need that little bit more....
kotik is offline  
0
Reply With Quote
      04-09-2013, 01:49 AM   #34
kaiv
Major
 
Drives: E92 M3
Join Date: Mar 2010
Location: San Diego, CA

Posts: 1,232
iTrader: (15)

Quote:
Originally Posted by kotik View Post
F1 cars have a form of MDM, so do Le Mans Cars, so do DTM cars.... there was a vid of DTM driver explaining MDM slip angles. It's not a bad thing to have on a track. Say Nordschleife, you better be rich to run without. Many pro's crash on the ring.

I wish we could program MDM more than euro mdm... I think US is 4% slip vs Euro is 7% slip. Wish we could do like 10-11%... I just need that little bit more....
F1, Le Mans, DTM etc are top of the food chain race cars. Multimillion dollar engineering, big stakes, competing to win etc.

It's just silly to compare them to our peasant street cars we drive at DEs on Sundays. There is no DE championship or stakes here.

Learn to drive with your own steering, throttle and braking inputs. It's also more rewarding.
kaiv is offline   United_States
0
Reply With Quote
      04-09-2013, 05:53 AM   #35
CanAutM3
Brigadier General
 
CanAutM3's Avatar
 
Drives: 2015 M4 DCT
Join Date: Jan 2012
Location: Montreal

Posts: 3,527
iTrader: (0)

Garage List
2008 BMW M3  [0.00]
2006 Audi S4  [0.00]
Quote:
Originally Posted by kotik View Post
F1 cars have a form of MDM, so do Le Mans Cars, so do DTM cars.... there was a vid of DTM driver explaining MDM slip angles. It's not a bad thing to have on a track. Say Nordschleife, you better be rich to run without. Many pro's crash on the ring.

I wish we could program MDM more than euro mdm... I think US is 4% slip vs Euro is 7% slip. Wish we could do like 10-11%... I just need that little bit more....
Traction control and stability systems have been banned from F1 quite a few years ago. This was done to put more of the driving in the drivers hands .
CanAutM3 is offline   Canada
0
Reply With Quote
      04-11-2013, 12:17 AM   #36
TheKosherStogie
Lieutenant Colonel
 
TheKosherStogie's Avatar
 
Drives: 08 M3 DCT AW/Red
Join Date: May 2009
Location: West Hollywood

Posts: 1,593
iTrader: (1)

Just my 2 cents about MDM, I will use it on a new track or if I'm trying to get comfortable with a car or want to push the car more than normal in a very high speed turn to build confidence then turn it off. I.e willow springs turn 8 going from 124 to 129. To be honest it's a bit nerve wrecking and a little extra confidence is nice. Already spun an Evo at 130 there ;(
TheKosherStogie is offline   United_States
0
Reply With Quote
      04-11-2013, 08:31 AM   #37
jbraslins
Latvian Gangstah
 
jbraslins's Avatar
 
Drives: 2015 F80 SO M3 M-DCT, ETA July
Join Date: Jun 2010
Location: Wake Forest, NC

Posts: 373
iTrader: (1)

I could definitely feel MDM grabbing the rear wheels coming out of corners on the gas. It was like a quick "bam bam bam bam bam" feeling. At first I thought my car was bouncing in the rear and I had rebound dampening issues.
Took a picture of the rear rotor yesterday while putting street pads back on. You can see the notches from where the brake pads were hitting the rotor intermittently. Must have been pretty hard, because I ran entire day after that with DSC OFF and notches are still visible.



__________________
2015 YMB BMW M3 M-DCT
[SOLD] 2010 Alpine White E90 M3 M-DCT
[SOLD] 2002 TiAg E46 M3 manual
jbraslins is offline  
0
Reply With Quote
      04-12-2013, 02:32 PM   #38
admranger
First Lieutenant
 
admranger's Avatar
 
Drives: 2002 M3, 2005 X5, 2011 M3
Join Date: May 2011
Location: Las Vegas

Posts: 364
iTrader: (0)

Quote:
Originally Posted by kotik View Post
It's not a bad thing to have on a track. Say Nordschleife, you better be rich to run without. Many pro's crash on the ring.
FWIW, the two times I was at the BMW Club Europa's 'ring school, I always drove with traction control off (2002 M3, 2003 330i ZHP). I drove the A1-ring in a driving rainstorm with the TC off in 2002. No big deal if you know what you are doing, though we had the benefit of Derrek Bell giving us pointers on driving in the wet so we may have had a *slight* advantage. Drive within your talent limits and TC is unnecessary.

I've seen a car crash b/c the traction control was on (it was very wet) but the skilled driver could not control the car with all the electronics trying to save him. It may have been better for him to just take his hands off the wheel for all the good the electronics did him.

The E9x is a bit of a problem b/c of the outstanding power of the car, the grip of modern tires being close to or exceeding the r-comps of old, and the very limited capabilities of the drivers, myself included. Couple these with the mass of the E9x platform, and you have a very high kinetic energy car with drivers thrashing it around like it is an E30M3 on forgiving tires. Big problems await.

In 1995 with the E36M3 we had these same discussions b/c we knew no-one at the track was as capable as the car was. People went off track with abandon back then too.
__________________
'11 E90 M3, Mebourne/Black/Fox Red/Black, 6MT, PP2, heated seats, moonroof, split folding rear seats, iPod/USB adapter, Technic harness, JL XD 6/600.
'02 E46M3, Imola/Black, 6MT, CWP, no sunroof, Ohlins, Eibachs, PFC DD rotors, PFC pads! HAT Clarus/Legatia speakers, 2 big amps in the back.
'05 X5 4.4i, Imola/Black, Premium, Cold, HAT Imagine 6.5's, Intravee iPod adapter
admranger is online now  
0
Reply With Quote
      04-12-2013, 04:37 PM   #39
CanAutM3
Brigadier General
 
CanAutM3's Avatar
 
Drives: 2015 M4 DCT
Join Date: Jan 2012
Location: Montreal

Posts: 3,527
iTrader: (0)

Garage List
2008 BMW M3  [0.00]
2006 Audi S4  [0.00]
Quote:
Originally Posted by admranger View Post
FWIW, the two times I was at the BMW Club Europa's 'ring school, I always drove with traction control off (2002 M3, 2003 330i ZHP). I drove the A1-ring in a driving rainstorm with the TC off in 2002. No big deal if you know what you are doing, though we had the benefit of Derrek Bell giving us pointers on driving in the wet so we may have had a *slight* advantage. Drive within your talent limits and TC is unnecessary.

I've seen a car crash b/c the traction control was on (it was very wet) but the skilled driver could not control the car with all the electronics trying to save him. It may have been better for him to just take his hands off the wheel for all the good the electronics did him.

The E9x is a bit of a problem b/c of the outstanding power of the car, the grip of modern tires being close to or exceeding the r-comps of old, and the very limited capabilities of the drivers, myself included. Couple these with the mass of the E9x platform, and you have a very high kinetic energy car with drivers thrashing it around like it is an E30M3 on forgiving tires. Big problems await.

In 1995 with the E36M3 we had these same discussions b/c we knew no-one at the track was as capable as the car was. People went off track with abandon back then too.
The E9X M3 (and the E46 for that matter) has another little hidden devil, it's hidden in the M-differential when driving in the wet. The M-differential is great to power out of corners or to do nice controlled drifts. However, when you hit a big enough puddle of water with only one rear wheel while under full acceleration, the differential will send all the power to the opposite wheel. This will instantaneously throw the cars sideways . Ask me how I know .

This one of the reasons I believe it is more prudent driving with DSC or MDM activated on a wet track.

Last edited by CanAutM3; 04-12-2013 at 05:02 PM.
CanAutM3 is offline   Canada
0
Reply With Quote
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 12:09 AM.




m3post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST