Welcome to the North American Subaru Impreza Owners Club Friday April 25, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Texas Impreza Club
Texas Impreza Club Forum sponsored by Gillman Subaru Houston
and Gillman Subaru San Antonio
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Chapters > Texas Impreza Club Forum -- TXIC

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 05-05-2007, 06:29 PM   #1
Aku Zaan
Scooby Newbie
 
Member#: 138613
Join Date: Jan 2007
Chapter/Region: TXIC
Location: Houston, TX
Vehicle:
2006 Impezra WRX STi
Crystal Gray Metallic

Subaru Stars Track Day: Tires and Brakes

Greetings All: I thought about posting in the technical area for this, but I decided I care more about what you guys think.

I am running in a track event this weekend, and am having serious FADE.

The first several laps everything goes great, but as things start to heat up the pedal gets real squishy (yes a technical term). I assume that the rubber brake lines are simply heating up and that is the source of the problem.

I bled the breaks while off the track today and that seemed to help some.


Anyone else had something similar, and or knows something I can do to minimize this until I can switch out for stainless? (other than slowing down, or stopping the use of the brakes )


Also for the racers in the group, what cold pressure do you guys run? I am still on stock STi wheels and tires.

Thanks.....that is all
* Registered users of the site do not see these ads.
Aku Zaan is offline   Reply With Quote
Old 05-05-2007, 06:39 PM   #2
Texas25RS
Scooby Guru
 
Member#: 3148
Join Date: Dec 2000
Chapter/Region: TXIC
Location: DFW, TX
Vehicle:
2012 Mazdaspeed 3
Crystal White Pearl Mica

Default

TRhe squish is most likely NOT your brake lines. You are probably boiling the brake fluid and/or over working your pads. The REAL answers for your problems would be to upgrade to a better brake pad (it is easy to change pads at the track, so you could buy a better track pad JUST for the track and use your street pads on the street) and replace your brake fluid with a better fluid (like Super Blue or even the Valvoline Synthetic). Replacing your brake lines won't help you very much...
Texas25RS is offline   Reply With Quote
Old 05-05-2007, 06:46 PM   #3
Hotrodguru
Scooby Guru
 
Member#: 37210
Join Date: May 2003
Chapter/Region: International
Location: in a Shotgun House FTW!
Vehicle:
2002 Tarmac Bugeye
2007 Muddy FJ Cruiser

Default

You need two things...pads and fluid to start off.

My personal preference:

Hawk HP + Pads
ATE Super Blue Fluid
Hotrodguru is offline   Reply With Quote
Old 05-05-2007, 06:59 PM   #4
afpdl
Scooby Guru
 
Member#: 26361
Join Date: Oct 2002
Chapter/Region: TXIC
Location: Sugar Land (Houston), Tx
Vehicle:
My shenanigans are
cheeky and fun

Default

Steel lines heat up just like rubber ones. Just like they said the problem is your pads and fluid.
afpdl is offline   Reply With Quote
Old 05-05-2007, 07:04 PM   #5
LiquidIQ
Scooby Guru
 
Member#: 6408
Join Date: May 2001
Chapter/Region: TXIC
Location: Austin, TX
Vehicle:
2004 MINI 2011 WRX
Dark Silver & White

Default

Quote:
Originally Posted by Hotrodguru View Post
You need two things...pads and fluid to start off.

My personal preference:

Hawk HP + Pads
ATE Super Blue Fluid
The Hawk HP did so-so on my MSR run the other month. I think a HP Plus would be a better bet if you want something you can street/light track with.

The HP held up, but I wasn't going balls out since there was water on the track.
LiquidIQ is offline   Reply With Quote
Old 05-05-2007, 09:05 PM   #6
Aku Zaan
Scooby Newbie
 
Member#: 138613
Join Date: Jan 2007
Chapter/Region: TXIC
Location: Houston, TX
Vehicle:
2006 Impezra WRX STi
Crystal Gray Metallic

Default

Ok....Thanks All

I am already running Motol fluid and have had several people help me check the pads, but I guess I am exceeding what the stock STi pads will handle.
Aku Zaan is offline   Reply With Quote
Old 05-05-2007, 10:44 PM   #7
Hotrodguru
Scooby Guru
 
Member#: 37210
Join Date: May 2003
Chapter/Region: International
Location: in a Shotgun House FTW!
Vehicle:
2002 Tarmac Bugeye
2007 Muddy FJ Cruiser

Default

Quote:
Originally Posted by LiquidIQ View Post
The Hawk HP did so-so on my MSR run the other month. I think a HP Plus would be a better bet if you want something you can street/light track with.

The HP held up, but I wasn't going balls out since there was water on the track.
Yeah, I've used the non + Hawks and some Axxis at a few track days. Not at MSR but at TWS. Talk about fade city...especially with the Axxis. Turn one though at TWS does have a much higher entry speed.

The +'s on the other hand did quite well, didn't fade at all till some really long stints.
Hotrodguru is offline   Reply With Quote
Old 05-05-2007, 11:42 PM   #8
Edward STi
Scooby Newbie
 
Member#: 98279
Join Date: Oct 2005
Chapter/Region: TXIC
Location: Austin
Vehicle:
1998 CannondaleCAAD3
Dirt

Default

I'm a big fan of PF 97's. I used them on my Lightning and I've seen several guys run them on their STi's with good results. One other thing you make want to consider is your braking technique. If your charging every corner, you could be overdriving the car. Regarding tire pressures, street rubber shouldn't be run above about 42psi hot. There's no easy answer on what that equates to cold since each corner will see different loads which vary with track and direction. Given the STi's push, I recommend equal tire pressures front to back - assuming a stiffened rear sway.
Edward STi is offline   Reply With Quote
Old 05-06-2007, 12:42 AM   #9
salaki
Scooby Guru
 
Member#: 10572
Join Date: Sep 2001
Chapter/Region: TXIC
Location: RollYourFender
Vehicle:
92X N62B44, ST 1050
CGK, LAX, & DFW

Default

I started @ 34 before the start of every sessions.
Usually about 1-2 hours wait until the next session.
And ended up w/ 38-40 psi hot.

For brake setup...
I'm still using stock STi pads and Valvoline fluid w/ SS lines.
The fluid lasted me 2 days w/ total of 8 sessions and still drives home good and can be used for daily drive until the next flush usually 1 day before track day

You might have overworked your brake.
Do you brake deep in a split second (late brake) or do you brake longer (not as deep/early brake) when you approach the turn? This might be a reason that you drag your brake too long that it heated up unnecessarily.

My STi can go up to 100-107mph (speedo) on straight line in MSR Cresson/Dallas.
I don't know about MSR Houston. This track might have a higher speed on the straight line before the turn = need a better pad.

Let us know what pads you decide to use because I'm considering to upgrade my pads too once this stock one is finished.

Last edited by salaki; 05-06-2007 at 12:51 AM.
salaki is offline   Reply With Quote
Old 05-06-2007, 02:00 AM   #10
dsmith
Scooby Specialist
 
Member#: 13203
Join Date: Dec 2001
Chapter/Region: MWSOC
Location: Toledo, OH
Vehicle:
88 & 87 528e, 88 M5
Aspire Rally car

Default

Stainless lines only change pedal feel. as noted, lines have nothing to do with fade. they are still rubber lines inside. i don't like them, 'cuz i can't tell if the line is damaged as easily. if you use them on the track, make them 1-2 year replacement item, i do it every year.

Your stock brakes should be fine (if you don't have crazy power), so you must be way over using them, have completely cooked fluid, and/or you have a stuck caliper (check uneven pad wear). Ex: I ran my stock 06 2.5i for 4 hours at MSRH one day w/o issue (just needed to replace pads after lunch).

I'm guessing you have instructors? So have them note your brake use.

Let us know what you find.

David
dsmith is offline   Reply With Quote
Old 05-06-2007, 02:35 AM   #11
Pantera
Scooby Specialist
 
Member#: 60692
Join Date: Apr 2004
Chapter/Region: TXIC
Location: www.apexdrivingacademy.com
Vehicle:
08 Z06
WRB FRB 4 LIFE!

Default

Once again! EBC Yellows for track and street use on every car I own.

I spend a lot of time on the track. They are great.

Last edited by Pantera; 05-06-2007 at 02:45 AM.
Pantera is offline   Reply With Quote
Old 05-08-2007, 12:58 AM   #12
scottjua
Scooby Specialist
 
Member#: 2937
Join Date: Nov 2000
Location: Plano, TX
Vehicle:
2002 WRX Wagon WRB
2006 STi Aspen White

Default

On the track in both wagon and STi we run ATE Super Blue/Type 200 (the gold type 200 is the same as blue, just different color for easy fluid flushes) fluid, and Carbotech Panther Plus pads. The wagon can make do with bobcat street pads in the rears, and P+ up front, but after the first track day in the STi, I was fading the stock pads and fluid quite a bit at the end of the day.

Another issue is cooling...

As my lap times drop throughout the day and I get into the groove, I can feel that even the P+ pads and ATE fluid can't handle some of the intense heat without enough air flowing over the rotors and pads between braking zones. I will seek out a cheap duct plan to hopefully get some more cool air to the rotors a la the guy with the White 06 Sti who seems to always be at MSR Cresson when I go. He's an older gentleman, but if you ever see him, ask him about his brake ducting mod.
scottjua is offline   Reply With Quote
Old 05-08-2007, 01:01 AM   #13
afpdl
Scooby Guru
 
Member#: 26361
Join Date: Oct 2002
Chapter/Region: TXIC
Location: Sugar Land (Houston), Tx
Vehicle:
My shenanigans are
cheeky and fun

Default

Another interesting brake cooling product http://www.fourproducts.com/FSBC.html
afpdl is offline   Reply With Quote
Old 05-08-2007, 10:10 AM   #14
Aku Zaan
Scooby Newbie
 
Member#: 138613
Join Date: Jan 2007
Chapter/Region: TXIC
Location: Houston, TX
Vehicle:
2006 Impezra WRX STi
Crystal Gray Metallic

Talking

Quote:
Originally Posted by dsmith View Post
I'm guessing you have instructors? So have them note your brake use.

Let us know what you find.

David

Yes we have instructors available, I grabbed one of the advanced instructors who also happened to be a mechanic and we went for a ride. I also had him take a look at the pads etc. We also got with the tech onsite who had bled my brakes at lunch on the first day.



Pads were wearing evenly, but down to between 20 and 30 percent of total, fluid looked fine at the time of bleed, but we flushed it anyway.
On the driver error side of things, we adjusted my braking zones, as fade became an issue I backed them up and reverted to the everyday driving “long brake zones” so I was carrying a lot more heat than I needed to. Getting the balls to trust the brakes and go back to a racing brake zone helped quite a bit. This event was held and TWS and I must admit my balls shrivel up as I dive down into turn one at between 120 and 130 and then floor it down the hill to help stabilize in the transition. I can’t imagine what will happen to them when we run clockwise I am diving down looking at 15, 14, 13. God save me.


Actions: I am in the process of finding new pads, going to hold off on rotors until I eat these up a bit more, but when that happens I will get something that is drilled or slotted. For the rest, I just have to make myself better.

B
Aku Zaan is offline   Reply With Quote
Old 05-08-2007, 11:39 AM   #15
dsmith
Scooby Specialist
 
Member#: 13203
Join Date: Dec 2001
Chapter/Region: MWSOC
Location: Toledo, OH
Vehicle:
88 & 87 528e, 88 M5
Aspire Rally car

Default

Quote:
Originally Posted by Aku Zaan View Post
On the driver error side of things, we adjusted my braking zones, as fade became an issue I backed them up and reverted to the everyday driving “long brake zones” so I was carrying a lot more heat than I needed to. Getting the balls to trust the brakes and go back to a racing brake zone helped quite a bit. This event was held and TWS and I must admit my balls shrivel up as I dive down into turn one at between 120 and 130 and then floor it down the hill to help stabilize in the transition. I can’t imagine what will happen to them when we run clockwise I am diving down looking at 15, 14, 13. God save me.

B
Thanks, that confirmed my suspicions. I've only had fade at TWS on stock cars after 45 min sessions. There's plenty of room between turns at TWS to cool the brakes, if not overused. Yes, clockwise is a shriveler coming off the banking before braking! It's really fun at the start of a race with 30 cars...

sounds like a good time. you'll get better, don't worry, but pads and better fluid will help. I personally don't like the colored blue/gold fluids cuz it stains everything. i like the Ford fluid. you can get it at any dealer, it's cheap, and as good as the rest. learn more about proper/efficient braking on track and you'll be much faster and almost no fade.

David

Last edited by dsmith; 05-08-2007 at 11:47 AM.
dsmith is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tire and brake "consumption" for 3 to 4 track days a year spacejunkiehsv Motorsports 9 04-15-2008 06:44 PM
small diameter tires and braking aspera Brakes, Steering & Suspension 22 12-25-2002 03:02 PM


All times are GMT -4. The time now is 02:36 AM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.