uneven left vs right rear brake pad wear - Rennlist - Porsche Discussion Forums

Notices
Racing & Drivers Education Forum
Sponsored by:
Sponsored by:

uneven left vs right rear brake pad wear

Reply

Old 10-06-2008, 06:25 PM
  #1
997gt3north
Super User
Thread Starter
 
997gt3north's Avatar
 
Join Date: Nov 2006
Location: Toronto
Posts: 2,188
Default uneven left vs right rear brake pad wear

- figured this was the forum to ask the question on
- my car 997gt3 with ceramics but running the motorsport green pads

- the stock pads were wearing very fast so i decided to try the greens (went through 5 sets of the stocks)
- the greens definitely last longer (much longer) but i noticed something with these greens that didn't happen with the stock pads (maybe because they went so fast, maybe it was because i was running a bunch of different tracks, maybe i'm trail braking more as i get faster, maybe the Paul Guard 50/80 LSD is causing it)

the issue
- the left rear pads were much more worn than the right rears
- i have done a bunch of days (almost all at Mosport in Toronto)
- Mosport is a clockwise track

- can anyone explain why the left side rear pads would wear more than the right side?
- i have some guesses but i would like some feedback from the track pros


thanks


paul
997gt3north is offline  
Reply With Quote
Old 10-06-2008, 07:03 PM
  #2
RonCT
Moderator
Rennlist Member
 
RonCT's Avatar
 
Join Date: Oct 2004
Location: Connecticut
Posts: 4,976
Default

Traction Control on or off?
RonCT is offline  
Reply With Quote
Old 10-06-2008, 09:24 PM
  #3
997gt3north
Super User
Thread Starter
 
997gt3north's Avatar
 
Join Date: Nov 2006
Location: Toronto
Posts: 2,188
Default

Originally Posted by RonCT View Post
Traction Control on or off?
always off
997gt3north is offline  
Reply With Quote
Old 10-06-2008, 11:17 PM
  #4
todinlaw
Addict
Rennlist Member
 
todinlaw's Avatar
 
Join Date: Nov 2007
Location: Columbus Ohio
Posts: 1,394
Default

When you say much more, are we talking about like 20 to 30% more? i I have never seen a left right differential. Thinking trail braking and turning left would cause more load on the outside left but I don't think that can explain it. check the location and condition of the pad retaining spring on the left. if it was not centered it could cause some excessive wear, otherwise I am clueless.
todinlaw is offline  
Reply With Quote
Old 10-07-2008, 12:11 PM
  #5
997gt3north
Super User
Thread Starter
 
997gt3north's Avatar
 
Join Date: Nov 2006
Location: Toronto
Posts: 2,188
Default

Originally Posted by todinlaw View Post
When you say much more, are we talking about like 20 to 30% more? i I have never seen a left right differential. Thinking trail braking and turning left would cause more load on the outside left but I don't think that can explain it. check the location and condition of the pad retaining spring on the left. if it was not centered it could cause some excessive wear, otherwise I am clueless.
- this is the first time i've seen this
- left rear pads maybe 2mms left
- right rear pads 6mm left
- fronts as usually more like 8 to 10mm
- the Motorsport Greens come about 2-3mm thicker than the stock ceramic pads which have about 10mm of material when new

- i check if the pistons on both rears and everything appears to be working

- what i'm left with is thinking that it must be trail braking on a clockwise track (left side wheels turning and braking more than the right side) and when i added my Paul Guard 50/80 LSD it has allowed the car to be even more stable under braking and thus i must be using even more trail braking

- if this isn't it then i must have left the tc button a few times and missed it
997gt3north is offline  
Reply With Quote
Old 07-21-2014, 03:00 PM
  #6
jumper5836
Super User
 
jumper5836's Avatar
 
Join Date: Mar 2004
Location: GTA, Canada
Posts: 7,941
Default

I am getting 30-40% more wear of front left pad then the right front pad. Rears appear to be even.

At Mosport which I am trail braking in 4 right hand corners 1, 3, 5, 8 and not I am not really doing any in the left hand corners.

Thinking the left front is doing the most braking since it is the loaded wheel. This is in a 996tt with PSM on. PSM is never disabled while braking regardless of being on/off with this car.
jumper5836 is offline  
Reply With Quote
Old 07-21-2014, 03:57 PM
  #7
GTgears
Super User
 
GTgears's Avatar
 
Join Date: Oct 2009
Location: Loveland, CO
Posts: 4,527
Default

When you install our LSD on that chassis, we pretty much universally hear about a reduction in the rate of rear brake pad wear because the more aggressive LSD makes it so that the traction control become much less active.

If the LSD is contributing to the pad wear in any way, I would suspect that it is as you mentioned, because you are now trail braking harder than you did previously.
GTgears is offline  
Reply With Quote
Old 07-21-2014, 07:38 PM
  #8
JCP911S
Addict
Rennlist Member

 
JCP911S's Avatar
 
Join Date: Mar 2004
Posts: 5,336
Default

Could also be ABS. On clockwise course, right rear tire will typically be lightly loaded, and more prone to lock-up, so makes sense it should have consistently less use and wear under trail-braking situations.
JCP911S is offline  
Reply With Quote
Old 07-21-2014, 11:12 PM
  #9
2BWise
User
 
2BWise's Avatar
 
Join Date: Nov 2004
Location: Northville, MI
Posts: 1,259
Default

Originally Posted by JCP911S View Post
Could also be ABS. On clockwise course, right rear tire will typically be lightly loaded, and more prone to lock-up, so makes sense it should have consistently less use and wear under trail-braking situations.
This! Its very probable its ABS causing what you see as uneven wear left to right. Even if you're not feeling the pedal pulsing it may very well still be active, especially while trail braking. With lateral load transfer the outside wheels will have more capability to produce brake force and ABS will be actively reducing it on the inside, therefore you would definitely see varied wear rates.
2BWise is offline  
Reply With Quote
Old 07-21-2014, 11:37 PM
  #10
Dave DE
User
 
Join Date: Apr 2006
Location: DE
Posts: 254
Default

I experience the uneven wear with my 987 also. I've used stick on indicators to look at caliper temps and found the left side (higher wear) calipers run hotter. So they appear to be doing more work.
Dave DE is offline  
Reply With Quote
 

Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
997gt3north
997 GT2/GT3 Forum
307
05-22-2017 01:01 PM
RacingBrake
991 GT3 GT3RS and 911R
10
05-09-2016 12:30 AM
997gt3north
997 GT2/GT3 Forum
60
01-26-2015 04:06 PM
savyboy
997 GT2/GT3 Forum
25
03-22-2012 11:47 PM
blake
996 GT2/GT3 Forum
24
04-24-2008 07:56 PM


Thread Tools
Search this Thread
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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump


All times are GMT -3. The time now is 11:40 AM.


Copyright ę 1998 - 2017 Rennlist.com
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: