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 > Suspension | Brakes | Chassis
 
GTB Performance
Post Reply
 
Thread Tools Search this Thread
      10-02-2012, 02:03 PM   #1
1MOREMOD
2014 Track Days - 6|Ridge 1:54:61|Pacific 1:35:72
 
1MOREMOD's Avatar
 
Drives: Race car->
Join Date: Mar 2009
Location: check your mirrors

Posts: 11,604
iTrader: (5)

minimum thickness

im running oem rotors with rs19s right now and my fronts are close to the magic 28.4 minumum thickness. what is the danger of running below that number? my thinking is that if you run well below it say under 27mm and you have worn your pads to a minimum thickness as well you run the risk of the calipers not being able to clap down enough and get a brake failure? by that logic as long as your pads are of significant thickness going under 28.4 wont matter. my rs19s are brand new so almost twice as thick as OEMs. Is what i am saying correct? thanks
__________________

02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings & bearings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW race|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs|
1MOREMOD is offline   United_States
0
Reply With Quote
      10-02-2012, 02:12 PM   #2
Porschefile
Major
 
Porschefile's Avatar
 
Drives: E92 M3
Join Date: Jul 2008
Location: Tennessee

Posts: 1,212
iTrader: (6)

That can happen, but it is my understanding that the minimum thickness is also the point at which the rotor may lose structural integrity. I know on my old E46 the rotors were just in general crummy condition at min thickness. I personally wouldn't run rotors below min thickness long at all, regardless of pad thickness. Your call as to whether to roll the dice.

Sounds like a good excuse for a bbk if you're out of warranty.
Porschefile is offline  
0
Reply With Quote
      10-02-2012, 02:50 PM   #3
1MOREMOD
2014 Track Days - 6|Ridge 1:54:61|Pacific 1:35:72
 
1MOREMOD's Avatar
 
Drives: Race car->
Join Date: Mar 2009
Location: check your mirrors

Posts: 11,604
iTrader: (5)

Quote:
Originally Posted by Porschefile View Post
That can happen, but it is my understanding that the minimum thickness is also the point at which the rotor may lose structural integrity. I know on my old E46 the rotors were just in general crummy condition at min thickness. I personally wouldn't run rotors below min thickness long at all, regardless of pad thickness. Your call as to whether to roll the dice.

Sounds like a good excuse for a bbk if you're out of warranty.
im not really a roll the dice kind of guy so will probably get new rings. It may sound funny but im actually trying to make my car as quick at the track as possible with stock suspension and brakes. weird goal i guess but thats what im shooting for at this point. although i do have upgraded pads, fluid, stainless lines, brake ducts ad08s, challenge sport, evolve stage 2 and vorshlag camber plates. kinda bending the rules but i still consider that stock unless i get coils or BBK.
__________________

02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings & bearings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW race|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs|
1MOREMOD is offline   United_States
0
Reply With Quote
      10-02-2012, 03:04 PM   #4
Porschefile
Major
 
Porschefile's Avatar
 
Drives: E92 M3
Join Date: Jul 2008
Location: Tennessee

Posts: 1,212
iTrader: (6)

Quote:
Originally Posted by chriszeh View Post
im not really a roll the dice kind of guy so will probably get new rings. It may sound funny but im actually trying to make my car as quick at the track as possible with stock suspension and brakes. weird goal i guess but thats what im shooting for at this point. although i do have upgraded pads, fluid, stainless lines, brake ducts ad08s, challenge sport, evolve stage 2 and vorshlag camber plates. kinda bending the rules but i still consider that stock unless i get coils or BBK.
To each their own, but I enjoy my car on track more with the coilovers and stuff. It isn't like there's some class keeping me stock and I enjoy it more the way it is. It just feels more planted and allows you to power down sooner etc.

Mine is stock compared to a stripped out track car
Porschefile is offline  
0
Reply With Quote
      10-02-2012, 03:14 PM   #5
1MOREMOD
2014 Track Days - 6|Ridge 1:54:61|Pacific 1:35:72
 
1MOREMOD's Avatar
 
Drives: Race car->
Join Date: Mar 2009
Location: check your mirrors

Posts: 11,604
iTrader: (5)

Quote:
Originally Posted by Porschefile View Post
To each their own, but I enjoy my car on track more with the coilovers and stuff. It isn't like there's some class keeping me stock and I enjoy it more the way it is. It just feels more planted and allows you to power down sooner etc.

Mine is stock compared to a stripped out track car
i guess its a way to keep cost down on mods for me also. i would like recaro seats, coilovers, bbk, and SC but im still getting quicker because of better driving not because i threw the price of used cayman s at it worth of parts. i probably will get to that point down the road but im making small incrimental changes for now and trying to get bang for the buck. also dont want to make my car something i dont enjoy anymore on the street because it has become so track oriented. I think pads, camber plates, harness, data logger, ducts, and the ad08s have all been very benificial.
__________________

02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings & bearings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW race|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs|
1MOREMOD is offline   United_States
0
Reply With Quote
      10-03-2012, 12:00 AM   #6
rzm3
Moderator
 
rzm3's Avatar
 
Drives: E92 M3
Join Date: Aug 2007
Location: USA

Posts: 4,598
iTrader: (14)

I would change them out as they approach the min. thickness of 28.40. Will your rotor suddenly crack at 28.39mm? Probably not, but safety always comes first

I am sure you can find many used rotors for a great price for sale on the market.
__________________
E92 M3 DCT - AiM EVO4 Data Logger / AiM SmartyCam HD / KW Competition 2-Way / OMP ARS Racing Seats / Brembo GT 365 / Pagid Yellow RS-29 / Rear Seats Delete
rzm3 is offline  
0
Reply With Quote
      10-03-2012, 09:28 AM   #7
bigjae1976
Takes threads off topic...daily
 
bigjae1976's Avatar
 
Drives: 11 E90 M3 Individual
Join Date: Mar 2006
Location: Milwaukee, WI

Posts: 5,218
iTrader: (11)

Garage List
2004 BMW M3  [4.50]
2011 BMW E90 M3  [5.00]
2013 BMW 328i  [5.00]
I might have a set of OEM rotors for sale soon. I'll PM you when I find out.

The biggest issue I see is structural integrity especially with drilled rotors. My experience is that heat cracking becomes more of an issue as the rotors become thinner. Not too bad with slotted but terrible with drilled rotors.
__________________


Sponsored by Momentum BMW #593...We Bleed BMW BLUE!
bigjae1976 is offline  
0
Reply With Quote
      10-03-2012, 09:34 AM   #8
1MOREMOD
2014 Track Days - 6|Ridge 1:54:61|Pacific 1:35:72
 
1MOREMOD's Avatar
 
Drives: Race car->
Join Date: Mar 2009
Location: check your mirrors

Posts: 11,604
iTrader: (5)

Okay let me know about your set for sale. On my inspection they don't look cracked yet around the drilled portion and have worn pretty well. Right now they are in the 28.8 range. Didn't check the rears. Just was taking a quick look when switching to new set of ad08s.
__________________

02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings & bearings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW race|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs|
1MOREMOD is offline   United_States
0
Reply With Quote
      10-03-2012, 10:04 AM   #9
STALKER
Brigadier General
 
Drives: 2008 E90 M3
Join Date: Feb 2009
Location: Toronto, ON

Posts: 3,630
iTrader: (5)

What's the min thickness you can the Pagid pads?
__________________

2008 AW/FR E90 M3-SOLD
2013 991 C4S
STALKER is offline  
0
Reply With Quote
      10-03-2012, 10:06 AM   #10
1MOREMOD
2014 Track Days - 6|Ridge 1:54:61|Pacific 1:35:72
 
1MOREMOD's Avatar
 
Drives: Race car->
Join Date: Mar 2009
Location: check your mirrors

Posts: 11,604
iTrader: (5)

not sure what your supposed to do but i generally shoot for 2mm. that number seems to prevent wear thru of the brake pad indicator.
__________________

02 Tiag e46 M3|6MT|GC plates|MCS c.o.|GC bars|GC race control arms|GC bushings & bearings|BW eng. & tran. mounts|subframe kit|BW race shifter|BW Jaffster|Euro header|BW race|K&N c.a.i.|Epic race tune|Rouge pulleys|Seibon CF hood|CSL bumper|ST-40|XR-2|SS lines|half cage|Recaro profi|Profi 2 harness|BMWpedals|BW studs|
1MOREMOD is offline   United_States
0
Reply With Quote
      10-03-2012, 06:43 PM   #11
Porschefile
Major
 
Porschefile's Avatar
 
Drives: E92 M3
Join Date: Jul 2008
Location: Tennessee

Posts: 1,212
iTrader: (6)

Quote:
Originally Posted by bigjae1976 View Post
The biggest issue I see is structural integrity especially with drilled rotors. My experience is that heat cracking becomes more of an issue as the rotors become thinner. Not too bad with slotted but terrible with drilled rotors.
Good point, I forgot about that. Worn slotted rotors are less dangerous than worn drilled rotors.
Porschefile is offline  
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 09:02 PM.




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