LS - 1st and 2nd Gen (1990-2000) Discussion topics related to the 1990 - 2000 Lexus LS400

Just installed new pads and rotors.

Thread Tools
 
Search this Thread
 
Old 07-12-14, 03:06 PM
  #1  
rick1987
Pole Position
Thread Starter
iTrader: (1)
 
rick1987's Avatar
 
Join Date: Oct 2012
Location: MA
Posts: 231
Likes: 0
Received 6 Likes on 5 Posts
Default Just installed new pads and rotors.

My rotors were warped as hell.

So I just installed Stoptech drilled and slotted rotors, and powerstop ceramic pads.

I just got back from braking them in. Holy Crap!

I don't know if it's because I was used to my old brakes, but these things are amazing!

I don't think I will ever use them to there true potential (drilled/slotted) but they look cool as hell. And the non friction surfaces are powdercoated.
Old 07-12-14, 07:48 PM
  #2  
python
Lexus Champion
iTrader: (4)
 
python's Avatar
 
Join Date: Jan 2008
Location: ca
Posts: 1,840
Received 26 Likes on 24 Posts
Default

http://www.carreview.com/cat/brakes/...3_6194crx.aspx
good luck!
Old 07-12-14, 10:00 PM
  #3  
rick1987
Pole Position
Thread Starter
iTrader: (1)
 
rick1987's Avatar
 
Join Date: Oct 2012
Location: MA
Posts: 231
Likes: 0
Received 6 Likes on 5 Posts
Default

Originally Posted by python
I didn't go with powerstop rotors. Just pads.

The rotors are Stoptech, supposedly they use Centric blanks.
Old 07-13-14, 01:20 AM
  #4  
PureDrifter
BahHumBug

iTrader: (10)
 
PureDrifter's Avatar
 
Join Date: Aug 2004
Location: California
Posts: 23,918
Received 94 Likes on 86 Posts
Default

Stoptech is owned by centric/is centric
Old 07-13-14, 09:41 AM
  #5  
Mugen_1
Lexus Test Driver

 
Mugen_1's Avatar
 
Join Date: May 2008
Location: Illinois
Posts: 812
Likes: 0
Received 1 Like on 1 Post
Default

Hopefully they work out for you - I've got R1 Concepts drilled/slotted on the front of mine and it didn't take them long to warp and become almost unbearable to live with. They need replaced and I've considered dropping back to blanks again but may consider slotted. Probably won't go with R1 Concepts again; second set of rotors that did that.
Old 07-13-14, 11:24 AM
  #6  
PureDrifter
BahHumBug

iTrader: (10)
 
PureDrifter's Avatar
 
Join Date: Aug 2004
Location: California
Posts: 23,918
Received 94 Likes on 86 Posts
Default

Originally Posted by Mugen_1
Hopefully they work out for you - I've got R1 Concepts drilled/slotted on the front of mine and it didn't take them long to warp and become almost unbearable to live with. They need replaced and I've considered dropping back to blanks again but may consider slotted. Probably won't go with R1 Concepts again; second set of rotors that did that.
sounds more like driving habits and your pad combination.

i'm at 2+ years on my R1C rotors, 2-3 vehicles.
Old 07-13-14, 11:31 AM
  #7  
RugbyDad
Pole Position
 
RugbyDad's Avatar
 
Join Date: Jun 2014
Location: NY
Posts: 250
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by PureDrifter
sounds more like driving habits and your pad combination.

i'm at 2+ years on my R1C rotors, 2-3 vehicles.
I was just going to say this. Overheated pads is what warps rotors most of the time. The pads get hotter than they can stand, melt and then fuse to the rotors. In most cases, the rotors are not the original source of the problem. And since you usually can't see warping just by looking at your rotor and or brake pads, people usually blame poor rotor construction.
Old 07-13-14, 11:41 AM
  #8  
Shmee
Lexus Test Driver
iTrader: (3)
 
Shmee's Avatar
 
Join Date: Dec 2007
Location: Victoria, BC. Canada
Posts: 1,471
Received 5 Likes on 4 Posts
Default

^^^^
Umm no, you will not get the pad or the rotors to the point of melting, ever. Especially pads fusing to the rotors... Even in all my years of racing I have never seen a pad "fuse" to a rotor.
Overheated ROTORS is what warps rotors all the time, not the pads.


Not sure what being able to see a warpped rotor has to do with people stating quality is the problem...


If a person drives the same all the time, replaces their rotors and the new rotors warp under the same condidtions but a lot faster, that's a "Quality and construction" issue. Cheap metal, poor construction. Could an extremely aggressive pad contribute to this, sure. But the rotor is still the weak link here.
Old 07-13-14, 11:59 AM
  #9  
RugbyDad
Pole Position
 
RugbyDad's Avatar
 
Join Date: Jun 2014
Location: NY
Posts: 250
Likes: 0
Received 1 Like on 1 Post
Default

Originally Posted by Shmee
^^^^
Umm no, you will not get the pad or the rotors to the point of melting, ever. Especially pads fusing to the rotors... Even in all my years of racing I have never seen a pad "fuse" to a rotor.
Overheated ROTORS is what warps rotors all the time, not the pads.


Not sure what being able to see a warpped rotor has to do with people stating quality is the problem...


If a person drives the same all the time, replaces their rotors and the new rotors warp under the same condidtions but a lot faster, that's a "Quality and construction" issue. Cheap metal, poor construction. Could an extremely aggressive pad contribute to this, sure. But the rotor is still the weak link here.
I'm not saying the pads themselves fuse to the rotor. I meant to say the materials of the pad fuse to the rotor.

Seeing these minor imperfections with the naked eye is probably impossible therefore a normal person wouldn't be able to tell if some of the pads materials fused to the rotor and would therefore blame their "warped" rotor on poor construction.

And nobody drives the same all the time. Hard braking situations occur on occasion (thus resulting in more friction/heat). Hows that saying go when someone refuses to let you borrow their car? "it's not you I'm worried about, It's the other drivers on the road."
Old 07-13-14, 01:27 PM
  #10  
python
Lexus Champion
iTrader: (4)
 
python's Avatar
 
Join Date: Jan 2008
Location: ca
Posts: 1,840
Received 26 Likes on 24 Posts
Default

material transfer is what most people refer to as warped rotors, its not the rotors that are the cause but the effect of pad material transfer to the rotors causing high spots.
Old 07-13-14, 01:30 PM
  #11  
python
Lexus Champion
iTrader: (4)
 
python's Avatar
 
Join Date: Jan 2008
Location: ca
Posts: 1,840
Received 26 Likes on 24 Posts
Default

http://www.examiner.com/article/ther...d-brake-rotors
Old 07-13-14, 03:22 PM
  #12  
Mugen_1
Lexus Test Driver

 
Mugen_1's Avatar
 
Join Date: May 2008
Location: Illinois
Posts: 812
Likes: 0
Received 1 Like on 1 Post
Default

Not trying to threadjack, but the pads I had on the first set of R1 d/s rotors were EBC RedStuff, and the second set were mated to Centric pads. Driving habits have been the same from when I got the car in 2007 until now; well over 100,000 miles of my own driving in that time period. Some days I can brake with no issues (for a brief period), then it's right back to shaking the steering wheel, vibrating the pedal and overall a very unsatisfactory braking experience.
Old 07-13-14, 03:40 PM
  #13  
Shmee
Lexus Test Driver
iTrader: (3)
 
Shmee's Avatar
 
Join Date: Dec 2007
Location: Victoria, BC. Canada
Posts: 1,471
Received 5 Likes on 4 Posts
Default

material transfer is a function of leaving the brakes engaged once they are smoking hot, it' is not "fusion" or fusing any more than burning an egg to the bottom of your frypan is.

rotors can and do warp, as can be seen with, thermal imaging, dual dial indicators or even placing rotors against each other. I have read a lot of scientific, university researched papers on this subject over the last year for some extracurricular stuff i am involved in.
high spots cause pedal pulsations which can reduce braking power, warped rotors often have no loss in pedal or braking power but can be felt through the wheel or the chassis depending on the location. both are visible when machining and can often be seen by holding the rotors together to check the hub offsets and/or backside trueness.

differential heating and cooling will case warpage in just about anything. plastic deformation of all metals will happen when heat is induced, to what order of magnitude will depend on the amount and duration of heat added vs the time and extent of the cooling. a rotor can reach and exceed the plastic deformation point and become warped causing a vicious sensual (through the steering wheel/chassis) and audible que, and then return to its normal relaxed state if cooled evenly and correctly.

Additionally, poor quality manufacturing processes will leave stress concentration pockets within the material and once heat is cycled into a rotor those stress concentrations can relax/contract and cause a warp. this is a case where no matter the process, once the warpage has occurred, it will not relax back to an unwrapped state.


The problem is most people do not know how to define their problem to be able to know which is which, so everything gets lumped into one big pile and called the same.
there are distinct differences between high spots or checking and warped rotors. the problem is there is so much varied info on the subject, that people tend to read one thing and assume it is true and therefore perpetuate the information they read as fact with no other research.


highspots or checks from material transfer are visible to the naked eye both before and after machining. discolouration (dark spots) is usually the most obvious sign but thermal checks usually accompany those dark spots. if left unattended long enough, these checks and high spots can increase in size engulfing a fairly large area of the rotor face, but are not uniform.

warpage is also visible to the naked eye during machining by entire swipes of the rotor face being missed on opposing sides of the same rotor. additionally, quality rotors have minimal runout down the vented surfaces, but are again very pronounced in a warped rotor condition. warpage is usually uniform in nature and in opposition from face to face when machined.
Old 07-13-14, 03:44 PM
  #14  
Shmee
Lexus Test Driver
iTrader: (3)
 
Shmee's Avatar
 
Join Date: Dec 2007
Location: Victoria, BC. Canada
Posts: 1,471
Received 5 Likes on 4 Posts
Default

additionally, poor quality alloys do not take heat as well as or are more susceptible to material transfer than higher quality alloys found in better parts.


metallurgy is where a lot of the cost of the quality stuff comes in.
Old 07-13-14, 05:21 PM
  #15  
python
Lexus Champion
iTrader: (4)
 
python's Avatar
 
Join Date: Jan 2008
Location: ca
Posts: 1,840
Received 26 Likes on 24 Posts
Default

https://www.google.com/search?q=do+b...472&gws_rd=ssl
show me 1 article that backs u up on brake rotors warping...im not going to get into a argument when I know im right and have proof to back up what I say...rotors do NOT "warp" under heat. over tightening maybe.run out of a hub is more of an issue also.


Quick Reply: Just installed new pads and rotors.



All times are GMT -7. The time now is 10:03 AM.