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
 
EXXEL Distributions
Post Reply
 
Thread Tools Search this Thread
      07-12-2020, 11:55 PM   #1
StogyBear
New Member
24
Rep
23
Posts

Drives: 2012 E92 M3
Join Date: Jun 2014
Location: Los Angeles

iTrader: (0)

Hey guys, I'm dealing with a strange issue. I daily and track my car a few times a year. I got the ds2500 pads after reading basically every post on this site and took the car to laguna seca (hard on brakes).

I drove the car about 8/10 and when leaving the track, I could hear the brakes juddering and squealing when coming to a stop. I checked and realized I had streaks of uneven pad deposits.

I took the brakes apart, ground the top layer of the rotor off with a hone tool, and reinstalled/greased everything up.

The squeal was instantly gone but juddering was improved by only like 30%. I did a few (6-7) hard 90-50mph stops and the brakes improved like 90%. I assumed I had successfully bedded the pads but I got home and saw uneven deposits on the rotors again!!

Is this the norm with these pads? Did I cook em while bedding? I'm not sure what I'm doing wrong here. When I had first installed them, without even bedding them they drove perfectly fine.

Photos below of the original deposits, refinishing rotors, and new deposits.
Attached Images
    
Appreciate 0
      07-13-2020, 07:01 AM   #2
//steve\\
Lieutenant
//steve\\'s Avatar
United_States
350
Rep
441
Posts

Drives: 2012 E92 M3
Join Date: May 2012
Location: Atlanta, GA

iTrader: (1)

I have these same pads on my full AP/Essex setup and have some braking vibration as well.

I haven't gone out to properly try to re-bed the pads yet either which I should do but curious.
__________________
Steve::::2012 AW E92::::IG - @sjs0433
Appreciate 0
      07-13-2020, 08:29 AM   #3
dparm
World's greatest HPDE driver
dparm's Avatar
United_States
2490
Rep
7,564
Posts

Drives: C7 Corvette Grand Sport
Join Date: Jun 2013
Location: Dallas, TX

iTrader: (1)

Some pads require bedding twice, depending on the state of the rotor. What pads did you run on these rotors before?
__________________
Now: 2017 Corvette Grand Sport
Past: 2011.5 M3 sedan ZCP
Appreciate 0
      07-13-2020, 01:48 PM   #4
StogyBear
New Member
24
Rep
23
Posts

Drives: 2012 E92 M3
Join Date: Jun 2014
Location: Los Angeles

iTrader: (0)

Quote:
Originally Posted by dparm View Post
Some pads require bedding twice, depending on the state of the rotor. What pads did you run on these rotors before?
Interesting. So following the same procedure twice? I wonder if regular street driving would eventually even it all out.

I had the Hawk HPS before this and hated it. Awful bite and modulation both on the street and track.
Appreciate 0
      07-13-2020, 02:18 PM   #5
dparm
World's greatest HPDE driver
dparm's Avatar
United_States
2490
Rep
7,564
Posts

Drives: C7 Corvette Grand Sport
Join Date: Jun 2013
Location: Dallas, TX

iTrader: (1)

Quote:
Originally Posted by StogyBear View Post
Interesting. So following the same procedure twice? I wonder if regular street driving would eventually even it all out.

I had the Hawk HPS before this and hated it. Awful bite and modulation both on the street and track.

Yes, do the bed-in procedure and then a day later, do it again. If you are not getting the blue mirror-like finish consistently across the rotor face, they're not fully bedded.

It can take two cycles if you switched compounds or had a lot of existing build-up from the previous pads. Have you ever used a Flex Hone tool?
__________________
Now: 2017 Corvette Grand Sport
Past: 2011.5 M3 sedan ZCP
Appreciate 0
      07-13-2020, 06:56 PM   #6
StogyBear
New Member
24
Rep
23
Posts

Drives: 2012 E92 M3
Join Date: Jun 2014
Location: Los Angeles

iTrader: (0)

Quote:
Originally Posted by dparm View Post
Quote:
Originally Posted by StogyBear View Post
Interesting. So following the same procedure twice? I wonder if regular street driving would eventually even it all out.

I had the Hawk HPS before this and hated it. Awful bite and modulation both on the street and track.

Yes, do the bed-in procedure and then a day later, do it again. If you are not getting the blue mirror-like finish consistently across the rotor face, they're not fully bedded.

It can take two cycles if you switched compounds or had a lot of existing build-up from the previous pads. Have you ever used a Flex Hone tool?
Yep I used the flex hone and cleared the rotors completely (front and back). That's why I'm puzzled.
Appreciate 0
      07-13-2020, 07:26 PM   #7
dparm
World's greatest HPDE driver
dparm's Avatar
United_States
2490
Rep
7,564
Posts

Drives: C7 Corvette Grand Sport
Join Date: Jun 2013
Location: Dallas, TX

iTrader: (1)

How did you bed them in?

https://www.zeckhausen.com/catalog/i...Path=6446_6443
__________________
Now: 2017 Corvette Grand Sport
Past: 2011.5 M3 sedan ZCP
Appreciate 0
      07-13-2020, 10:30 PM   #8
roastbeef
Lieutenant General
roastbeef's Avatar
United_States
6972
Rep
10,566
Posts

Drives: E92 M3
Join Date: Nov 2010
Location: Orange County, CA

iTrader: (2)

this might be more of a rotor problem rather than a pad problem. i've never used a flex hone on rotors. i suspect there just isn't a good way of knowing you aren't taking off too much material and actually creating an uneven rotor surface. the flex hone method is talked about from time to time, but i'm not sure if i've read that anyone swears by it. i'm a little skeptical.

on the subject of checking rotors, it looks like you are taking the rotors off, but just double check the inside of the rotor faces as they typically get hotter. an instructor once told me that the inside rotor face on the passenger side takes quite a beating at laguna due to the turn 2 braking zone, then the long, slow, left turn shielding that specific rotor face from significant airflow. in my experience, i found this to be true as just eyeballing the pads at the end of the day, the inside passenger pad is significantly more worn.
just give the inside rotor faces a closer look.
__________________
Instagram; @roastbeefmike
Appreciate 0
      07-13-2020, 10:53 PM   #9
StogyBear
New Member
24
Rep
23
Posts

Drives: 2012 E92 M3
Join Date: Jun 2014
Location: Los Angeles

iTrader: (0)

Quote:
Originally Posted by dparm View Post
I must have done it more aggressively than it asks for. I did 90-60 stops rather than 60-30.. 🤦*♂️
Appreciate 0
      Yesterday, 03:57 PM   #10
StogyBear
New Member
24
Rep
23
Posts

Drives: 2012 E92 M3
Join Date: Jun 2014
Location: Los Angeles

iTrader: (0)

Ended up bedding them again, this time taking my time to warm up the rotors and cool them down by driving about a mile without touching them. Juddering is pretty much all gone at this point, but now my front right squeals at low speeds. Is it common for these pads to squeal?

The rotors look a bit better now, but still have some deposits. Honestly, I'm not sure why these got such great reviews on here. They perform relatively well, but melt onto the rotors way too easily. Drilled rotors also are probably not ideal. As you can see, there are streaks starting from the drilled holes.
Attached Images
 

Last edited by StogyBear; Yesterday at 04:37 PM..
Appreciate 0
      Yesterday, 04:50 PM   #11
dparm
World's greatest HPDE driver
dparm's Avatar
United_States
2490
Rep
7,564
Posts

Drives: C7 Corvette Grand Sport
Join Date: Jun 2013
Location: Dallas, TX

iTrader: (1)

Quote:
Originally Posted by StogyBear View Post
Ended up bedding them again, this time taking my time to warm up the rotors and cool them down by driving about a mile without touching them. Juddering is pretty much all gone at this point, but now my front right squeals at low speeds. Is it common for these pads to squeal?

The rotors look a bit better now, but still have some deposits. Honestly, I'm not sure why these got such great reviews on here. They perform relatively well, but melt onto the rotors way too easily. Drilled rotors also are probably not ideal. As you can see, there are streaks starting from the drilled holes.





1. They can squeal slightly, it will improve as they bed in. This is the price you pay for track capability.

2. Double-edged sword with the holes.They will help the pads bite better, but also can result in streaking. My guess on your streaking is that you're just cooking those pads. They are not a true track pad but are trackable in the sense they don't fall off the cliff when they get too hot like an HPS.

It sounds like you are maxing out these pads due to insufficient cooling. Consider something more track-focused like a Hawk DTC-60/70 for your next set. FWIW I used the DS2500s on a Stoptech kit and they were fine, but those have massively better rotor and caliper cooling. If I were running a very sticky tire, I would have gone for the Hawks.
__________________
Now: 2017 Corvette Grand Sport
Past: 2011.5 M3 sedan ZCP
Appreciate 0
      Yesterday, 05:03 PM   #12
Ervin87
Second Lieutenant
United_States
48
Rep
235
Posts

Drives: E92 M3 | B5 S4 | E30
Join Date: Aug 2012
Location: Santa Clara, CA

iTrader: (5)

It is best to have a dedicated set of track pads to avoid these situations. PFC 08 work great and are endurance pads so they will last for a while, especially on a heavy car like this and Laguna, which is hard on brakes.
Appreciate 0
      Yesterday, 05:04 PM   #13
Z K
Brigadier General
Z K's Avatar
United_States
1430
Rep
4,898
Posts

Drives: E90 M3, F30 328i
Join Date: Jul 2011
Location: San Francisco

iTrader: (3)

DS2500 is not a track pad - it is designed for street use. You can get away with DS2500 on a light car for track use.. but definitely not on big heavy cars like the M3.

Every car I've ran these pads on track had really bad deposits all over after they get hot. The pad just melts and chunks apart when it gets hot.
__________________
Auto Detailing Enthusiast!
Appreciate 0
      Yesterday, 05:06 PM   #14
dparm
World's greatest HPDE driver
dparm's Avatar
United_States
2490
Rep
7,564
Posts

Drives: C7 Corvette Grand Sport
Join Date: Jun 2013
Location: Dallas, TX

iTrader: (1)

Quote:
Originally Posted by Z K View Post
DS2500 is not a track pad.

Every car I've ran these pads on track had really bad deposits all over after they get hot. The pad just melts and chunks apart when it gets hot.





It's fine for people who are new to HPDE and don't have super-sticky tires. But to your point, as soon as people start going faster, the pad will quickly prove itself to be the weak point -- hence my recommendation OP just uses these up and then goes to the Hawk DTC.
__________________
Now: 2017 Corvette Grand Sport
Past: 2011.5 M3 sedan ZCP
Appreciate 1
Z K1430.00

      Yesterday, 05:23 PM   #15
Z K
Brigadier General
Z K's Avatar
United_States
1430
Rep
4,898
Posts

Drives: E90 M3, F30 328i
Join Date: Jul 2011
Location: San Francisco

iTrader: (3)

Quote:
Originally Posted by dparm View Post
It's fine for people who are new to HPDE and don't have super-sticky tires. But to your point, as soon as people start going faster, the pad will quickly prove itself to be the weak point -- hence my recommendation OP just uses these up and then goes to the Hawk DTC.
I agree on going to some more track oriented pads.

IMHO, the DS2500 should be reserved for street use and some light track maybe in light cars.

A step up without leaving the street/track hybrids would be Project Mu HC+ and HC-CS. They can handle up to 800C and do not leave deposits. That or Endless MX72 PLUS - not the regular MX72, those also melt and leave bad deposits on track. Availability is spotty for these Japanese pads but they are excellent if you can get it.

My problem with the DTC is that they have corrosive brake dust that eats paint. You have to clean the car immediately after use. If you let it sit or worse yet, get it wet - you'll need to clay and polish it out of the wheels and car paint.
__________________
Auto Detailing Enthusiast!
Appreciate 0
      Yesterday, 08:42 PM   #16
dparm
World's greatest HPDE driver
dparm's Avatar
United_States
2490
Rep
7,564
Posts

Drives: C7 Corvette Grand Sport
Join Date: Jun 2013
Location: Dallas, TX

iTrader: (1)

Quote:
Originally Posted by Z K View Post
My problem with the DTC is that they have corrosive brake dust that eats paint. You have to clean the car immediately after use. If you let it sit or worse yet, get it wet - you'll need to clay and polish it out of the wheels and car paint.

That hasn't been my experience with nearly a dozen sets of them front and rear. No damage to the painted calipers, either set of wheels, or the car's paint. It comes right off with Iron-X and I even daily drive on those pads so the wheels sit dirty with them for a long time, sometimes.
__________________
Now: 2017 Corvette Grand Sport
Past: 2011.5 M3 sedan ZCP
Appreciate 0
      Yesterday, 09:57 PM   #17
StogyBear
New Member
24
Rep
23
Posts

Drives: 2012 E92 M3
Join Date: Jun 2014
Location: Los Angeles

iTrader: (0)

How much better is Project Mu HC+ from the DS2500? Is there a point in trying these or should I just do the track pads? I've gotten pad swapping down to 30 mins at this point so I'm thinking it's best to just get a pair of dedicated track pads.
Appreciate 0
      Yesterday, 10:59 PM   #18
dparm
World's greatest HPDE driver
dparm's Avatar
United_States
2490
Rep
7,564
Posts

Drives: C7 Corvette Grand Sport
Join Date: Jun 2013
Location: Dallas, TX

iTrader: (1)

Quote:
Originally Posted by StogyBear View Post
How much better is Project Mu HC+ from the DS2500? Is there a point in trying these or should I just do the track pads? I've gotten pad swapping down to 30 mins at this point so I'm thinking it's best to just get a pair of dedicated track pads.

Get real track pads, and get ones that are easy to find. Brands like Hawk, G-Loc, Carbotech, PFC, etc. are always available from tons of distributors.
__________________
Now: 2017 Corvette Grand Sport
Past: 2011.5 M3 sedan ZCP
Appreciate 0
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



All times are GMT -5. The time now is 07:59 AM.




m3post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.
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