Is300 breaks - TERRIBLE!? - Page 2 - Lexus IS Forum
User Tag List

 2Likes
Reply
 
LinkBack Thread Tools
post #16 of 22 (permalink) Old 12-01-2016, 12:03 AM
Enthusiast
 
Join Date: Dec 2002
Posts: 1,238
Mentioned: 4 Post(s)
Tagged: 0 Thread(s)
Quoted: 148 Post(s)
           
Quote:
Originally Posted by PhoenixLexi300 View Post
I've been looking at carbotech xp12 pads or project Mu pads. Rated for up to 800 deg Celsius.

Rotors I need some capable of handling the heat, best ones I found are good to 600c --Project mu club racer.

Anyone heard anything about these? Or have a recommendation?
You need pads to handle the heat, and rotors to shed the heat in between stops. The DBA design is slightly higher temp AFAIK then Project Mu Club racer and likely has cooling similar to the Project Mu SCR Pro type rotors based on internal fin design. There should be other equivalents on the market....

The best bias set up that I've had on my car was the Figs adapters, Supra TT rotors (DBA), and Hawk pads (keep forgetting that I have this in my garage should anyone want a good deal for a xmas present). From highway speeds it was slam me in my seat belt good and felt good in rain, or other poor conditions. For lower speed track days, I would have ran with this for as long as I could have.

I switched to 4 pistons because I wanted a more aggressive/higher temp capable pad with some street manners for over 600whp+. The Hawk pads are under 1000 before serious fade issues occur vs. <1500-1600 on what I have now. I'm confident I could stop down from 150+mph if needed, but the trade-off is brake bias. I can lock up the fronts before the rears which won't translate into shorter stopping distance in most situations. Situations where pads end up over 1000 it sure will stop better, but otherwise.... I doubt it.

On a pure numbers side... at one point, I built myself some calculators and looked at friction factor of all the pads I could find, and various brake options/diameters/etc. for the IS. The brake bias is borderline horrendous with 4 pistons up front on a large diameter rotor and an aggressive pad... while keeping stock diameter and calipers in the rear. Most internet wisdom will say 'stopping power comes from the front, my 4 pistons are awesome, and don't even touch the rear brakes'. But, I'm glad to see guys like Hardvin chiming in stating some actual truth that BBKs can ruin the bias and make things worse.

Personally, I think guys should be looking into rear brake upgrade options when doing 4 pistons on the IS. The options coming out for larger diameter rotors and 6 piston calipers front with larger diameter rotors and 4 piston rears merit more research... just as would some kind of rear brake upgrade to match 4 pistons now.

Some other reading/real world thoughts for you...

Brake Myth #1

Was watching a vid on tuned that made me think of this thread. 4 minutes in you can hear the fantastic race pad squeal. Even listen to the pro drivers comments after the lap test about too much brake up front, etc.
whatthe is offline  
Sponsored Links
Advertisement
 
post #17 of 22 (permalink) Old 12-12-2016, 09:45 PM
Newbie
 
Join Date: Feb 2009
Posts: 11
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
 
No fan of any ceramic pads- every set I have ever tried was returned and switched out.
Years ago I ran repco pads, cant find them anymore but found what I think is better.
Im running Porterfield's R4-s brake pads on the street and they are the best I have ever found.

If you are a scca racer they give a discount when you contact them direct.
They also sell many other makes and can help with brake pad advice.

Anyone compare the Parterfields to other brands?
datsunscott is offline  
post #18 of 22 (permalink) Old 12-16-2016, 07:53 PM
Lurker
 
Join Date: Jun 2007
Posts: 76
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
           
I use Carbotech XP12 Front and XP10 rear, Motul RBF600, and oem type plain rotors on my trackcar with Hoosier A6's. No issues as of yet with 15-20 minute sessions and not using air ducts at the moment. The backing plates are removed though.
bshown is offline  
 
post #19 of 22 (permalink) Old 12-18-2016, 01:57 PM Thread Starter
Newbie
 
Join Date: Jul 2016
Posts: 31
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
           
Quote:
Originally Posted by bshown View Post
I use Carbotech XP12 Front and XP10 rear, Motul RBF600, and oem type plain rotors on my trackcar with Hoosier A6's. No issues as of yet with 15-20 minute sessions and not using air ducts at the moment. The backing plates are removed though.
Good to know! This is almost exactly the setup I'm planning on running. For your rotors, are you using cheap ones like brembo blanks, or bosch blanks? Or are you using specialty rotors like DBA, Project Mu club racer, etc...? $150-$500 per piece.

ALSO, what is the function of the backing plates? My XP 12s didn't come with any, I was thinking to just peel the plates off the old pads and apply them, not a good idea?
PhoenixLexi300 is offline  
post #20 of 22 (permalink) Old 01-16-2017, 04:57 PM
Lurker
 
Join Date: Jun 2007
Posts: 76
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
           
Sorry just saw your reply. I should have been more specific. I removed the backing plates from the hubs themselves. The metal ones that look kinda like an air duct sticking out. I also do not use the shims for the brake pads. The rotors are just plain Centric type.
bshown is offline  
post #21 of 22 (permalink) Old 01-17-2017, 10:28 AM
Newbie
 
Join Date: Sep 2008
Location: Baltimore
Posts: 10
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
           
I used a similar setup but with Hawk HPS pads. Never had issues on track days and solid braking from 110->35.

Brake dust was bad thou....Hope that helps.
carbonell is offline  
post #22 of 22 (permalink) Old 02-20-2017, 09:45 AM
Supporting Vendor
 
THMotorsports's Avatar
 
Join Date: Nov 2007
Location: Chicago
Posts: 5,512
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
           
Late reply, but are you experiencing significant fade? I feel like your issue isn't necessarily with thermal capacity, but rather with a compound that is insufficient for track use. Get a better set of pads that offer more brake torque.

What tires are are you on? What tracks are you running on?

I use cheap blank rotors on track and just pair it with a decent pad. I take it you aren't tracking frequently enough to warrant a separate set of pads and rotors, but there are some great options that are still very streetable.

PM ME FOR ALL QUOTES.

Will Xiao
- Phone: 1-800-959-0145 EXT: 7028
- wxiao@thmotorsports.com
THMotorsports is offline  
Sponsored Links
Advertisement
 
Reply

  Lexus IS Forum > Lexus IS > Race Related

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Lexus IS Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself. If your address is invalid, you will likely lose access to the site.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Current users viewing this Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may 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 On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome