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Old 06-15-2011, 09:24 AM   #1
corey_dyck
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Default Boiling ATE SuperBlue - need ducts or upgraded pads?

I'm boiling freshly-bled ATE Super Blue fluid after 5 laps of our local 1.3 mile road course in a Solo1/SoloSprint/Time Attack/whatever situation. Symptoms are a very soft pedal, with it sinking completely to the floor after a full lap without touching the brakes. No pad fade, after pumping the brakes a few times it still stops well, although with a soft pedal. Would the next step be brake ducts for cooling or upgraded pads?

Depending on answers, I'm considering the Quantum Motorsports duct kit or Hawk DTC-60 pads, but am open to options. I've got some locals suggesting that higher-temp pads will fix the problem and brake ducts are useless, I can't wrap my head around how a higher allowable rotor temperature could reduce the chances of the fluid getting too hot...
*** If you feel the need to say "Search noob", please provide search terms that will supply this answer within the first 5 pages of findings. I've found lots of threads that suggest that others do a search, but no useful info.

Car details: 2006 STI, Ferodo DS2500 pads F&R, Cobb Stage 2 tune and 3" TBE, TIC AST coils, 24mm bars F&R, 17x9 Rotas with old crusty 255 Dunlop Z1s, KillerB oil pan and pickup.

Track: Gimli Motorsports Park, track map, surface is rough asphalt with LOTS of aggregate that likes to shred tires quickly without providing fantastic grip. Rough idea of speeds: 110mph into turn 1, 60mph through 1, 100mph into 3, 45mph through 3, 30mph though 5, 95mph exiting 6, 30mph through 9. I'm cautious into turns 3 and 9 as there are hard barriers on the runout if you go off at speed. Definitely a power track, small gains in power equal healthy drops in laptimes.

Driver: Autocrossing & tracking since 2000 in a wide variety of cars. Placed 8th (trophied) in A-Stock at 2008 SCCA Nationals. Been away from road courses for about 3 years, last car I drove on this circuit was a 500 hp Camaro. Did 3 years of wheel-to-wheel ice racing in both rubber-to-ice and studded classes. Definitely have lots more to learn, but want a car that stops reliably before really pushing it.

Videos from the track:

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Old 06-15-2011, 09:59 AM   #2
RB5 Clone
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Motul RBF 600
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Old 06-15-2011, 10:01 AM   #3
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Uh, if you're boiling the fluid with the pads you're using now, how do you expect upgraded pads to stop boiling the fluid? Don't listen to the locals.

The answer you're looking for is ducting.
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Old 06-15-2011, 10:40 AM   #4
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Remove dust shields first off and add some ducting.
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Old 06-15-2011, 10:45 AM   #5
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You could also look into some titanium shims to prevent soem heat from passing from the pads to the caliper. TurnInConcepts sells some, as well as some hub shims.

Ducts will help some, but will not fix it completely.

Running more aggressive pads in the rear than the front will help even out braking and tax the fronts less.

In the end, you will have to start bleeding between each session and saving up for a brake kit that moves the bias more rear, since the stock bias is overly focused on the front.

Be careful in the kit you choose, this car is a pig and even big name kits made for this car will not fix your problem.
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Old 06-15-2011, 12:12 PM   #6
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While ducting will definately help, you shouldn't be boiling the fluid that quickly regardless.

When you bleed the brakes, are you bleeding out BOTH ports on EACH caliper? I've seen quite a few miss this.

How used are the pads? Do they have >50% life left? If not, just getting new pads will help. Thin pads heat up quicker, retain more heat, and therefor transfer more heat to the caliper.

Definately take off the dust shields. That will make a big difference.
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Old 06-15-2011, 12:40 PM   #7
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Yes, bleeding inside first, then outside. From memory, the bleeding order was RF, LR, LF, RR. I pumped about a Liter through the 2nd time to be sure I got all the old stuff out.

Thanks for confirming my thoughts about hotter pads NOT keeping the fluid cooler somehow. Pads were new on Friday, about 2/3rds left now.

I'm considering the pad shims as well, though I noticed 316 Stainless has a lower coefficient of thermal conductivity than Titanium. (source) I may look into getting something lasered locally if that's a cheaper option. I'll sketch something up and get a quote.

Thanks for the tips, I'll likely order the Quantum kit in the next day or two.
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Old 06-15-2011, 12:55 PM   #8
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Also consider driving style changes to improve braking heat... shorter, harder braking zones heat the pads less than longer "riding the brake" zones.

but all-in-all the above posts are true... it's a heavy car with a lot of tire it can overheat quickly if you're not careful.
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Old 06-15-2011, 03:43 PM   #9
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I would upgrade the pads to a more track oriented spec (Ds3000, CL RC6 or Hawks)

Maybe you are overusing the brakes to make up for the lack of stopping power the ds2500 has (The 2500 is a street/light track duty pad maybe not suited to a relatively heavy car like the STI)

If a more agressive pad can lead to reduced braking time (better braking, so less time actually braking for the same decelleration)thus leading to lower caliper/disk/fluid temps.

Why not try a more track oriented pad that at first, it is probably the easiest/least expensive thing to try.If you still boil ATE after going with a higher torque/more track biased pad, then look into ducting (or into your own braking technique)
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Old 06-15-2011, 05:10 PM   #10
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I do track days at Calabogie motorsports... It`s a 3 miles 20 turns race course and I have racing slicks with DS2500, with ATE brake fluid... never able to boil it... I always bleed my system RR-LR-RF-LF... My pedal is always rock hard... I get fade,not boiling... This I`m gonna try ds 3000...

GL
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Old 06-15-2011, 05:17 PM   #11
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Titanium pad shims, remove dust shields, hub shims, remove fog light covers and add ducting report back with results..
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Old 06-15-2011, 05:22 PM   #12
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Quote:
Originally Posted by RB5 Clone View Post
Motul RBF 600
considering that ATE has nearly identical specs, a change to Motul won't amount to a hill of beans

remove the dust shields for sure and given that you're only running a DS2500 with a tire as grippy as a Z1, you really need better pads as well. Those tires can take a tremendous amount of heat, more than almost any other non r comp I'm aware of, and that will transmit it's way backwards - they need a tire that is equally capable if you're trying to run them aggressively

awfully hard to compare the same car on different tracks - driving style, as suggested, makes a tremendous amount of difference. Ti shims will help, but they are not going to solve the issue

Ducting should be part of any track oriented car running track oriented tires - regardless of their pad choice
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Old 06-15-2011, 05:27 PM   #13
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more aggressive rear pads!

look at how brown brembos get in the front vs. the rear. that happens for a reason.
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Old 06-15-2011, 06:16 PM   #14
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Quote:
Originally Posted by Dutch Scooby lover View Post
If a more agressive pad can lead to reduced braking time (better braking, so less time actually braking for the same decelleration)thus leading to lower caliper/disk/fluid temps.
The pads he has already have a 1300*F temperature threshold according to Essex. Hes not experiencing pad fade, if that was the case, then sure, try more aggressive pads.

Ducting and removal of the backing plates should be first. Take a look under any STI at the track, and any of them that arent running HPDE 1 have ducting.

Last edited by cucamelsmd15; 06-15-2011 at 06:24 PM.
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Old 06-15-2011, 08:56 PM   #15
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boiling fresh ate in 5 laps? something else is wrong. I have no ducts and on Hoosiers, I can go a whole weekend without bleeding. master cylinder problem? Cooling ducts will help fluid last longer, but I guarantee that is not your problem
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Old 06-15-2011, 10:24 PM   #16
corey_dyck
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What master cylinder problem could cause overheated fluid? Not being sarcastic or anything, I just don't know.

I should clarify that it's 5 laps after sitting for 6-7 minutes from the last session. Do a few of those in a row and the pedal gets soft.

Will removal of the backing plates will cause ball joint heat issues? I know it's painful to check tire pressures with an ungloved hand (radiant heat from rotors) if you're not quick, the poor ball joint boots must bake.
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Old 06-15-2011, 10:43 PM   #17
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Quote:
Originally Posted by corey_dyck View Post
What master cylinder problem could cause overheated fluid? Not being sarcastic or anything, I just don't know..
I'm saying it's not boiled fluid. Guessing at MC.

now you're saying it only happens on back to back sessions and in the 5th lap of the second session? just one back to back session or a bunch. don't release the facts little by little and expect a good answer

what do your pads look like? if you are really boiling ate, I would think your ferodos would be destroyed
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Old 06-16-2011, 01:43 AM   #18
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@ Cucamel.
I know the pad can take a certain temperature, but If one uses a pad to it's maximum capacity the temperature of the pad/pistons/caliper will go up eventually.

If one uses a more aggressive pad (and thus is able to decellerate at a higher rate) maybe the pads themselves get hotter, but If this better/hotter pad can reduce the time actually spent braking, and more time being not used/cooling down (and thus do not end up heating the rest of the braking system.

For example, purely too illustrate my opinion (and to clarify)

Pad X is mounted.
Car needs to slow down from 100 to 50 m/h, and this pad takes 6 seconds to achieve that.In those 6 seconds you build up heat in the pads/backing plate/pistons/fluid etc.
After those 6 seconds you release the brakes and accelerate (and thus the brakes can cool down)

Now mount Pad Z,, which can do the same thing,but in 3 seconds.
Maybe the pad itself gets hotter (the same energy energy dissipated in less time)but because the overall time on the brakes is halved the pads have less time to heat up the caliper/fluid.

I did not mean that he is getting brake fade, but maybe the language barrier is playing a part.
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Old 06-16-2011, 08:00 AM   #19
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Quote:
Originally Posted by Dutch Scooby lover View Post
@ Cucamel.
I know the pad can take a certain temperature, but If one uses a pad to it's maximum capacity the temperature of the pad/pistons/caliper will go up eventually.

If one uses a more aggressive pad (and thus is able to decellerate at a higher rate) maybe the pads themselves get hotter, but If this better/hotter pad can reduce the time actually spent braking, and more time being not used/cooling down (and thus do not end up heating the rest of the braking system.

For example, purely too illustrate my opinion (and to clarify)

Pad X is mounted.
Car needs to slow down from 100 to 50 m/h, and this pad takes 6 seconds to achieve that.In those 6 seconds you build up heat in the pads/backing plate/pistons/fluid etc.
After those 6 seconds you release the brakes and accelerate (and thus the brakes can cool down)

Now mount Pad Z,, which can do the same thing,but in 3 seconds.
Maybe the pad itself gets hotter (the same energy energy dissipated in less time)but because the overall time on the brakes is halved the pads have less time to heat up the caliper/fluid.

I did not mean that he is getting brake fade, but maybe the language barrier is playing a part.
Thats fine, but you're ignoring the fact that hes on street tires. Old ones at that... if he was on purple crack, then sure, I could go along with what youre saying.

The fact is the amount of air getting to the brakes is poor at best. Even if he did switch to a higher friction pad, my guess is the problem would still remain. Sure, braking times are reduced, but you still would have a hot pad sitting in a hot caliper. That heat has to have an outlet, either via the caliper or air exchange.

Also, one thing I havent seen mentioned yet, what kind of condition are wheel bearings in?
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Old 06-16-2011, 08:02 AM   #20
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I've found that DS2500 pads will not hold up for a full 20min session at my local 1.9mi track. They fade. They even fade with ti shims. It's more of a greasy feeling. Not a soft pedal that will pump up like a fluid problem.

Switching to DS3000 pads with the Ti shims solve this problem.

Never have tried the Ferodos with out the TI shims. The OEM JURID pads would start fade after about 10-15min. No Ti shims.

Since I Auto-X a little and hillclimb I am running full OEM backing plates.

One fun fact about the thermal conductivity of Ti and SS. At the temperatures that our brakes operate at Ti's conductivity goes down as the temp goes up and SS conducts better at higher temps. There must be a reason Ti brake pad shims are available off the shelf and SS ones are not...

Last edited by Web Foot STi; 06-16-2011 at 08:11 AM. Reason: I
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Old 06-16-2011, 08:10 AM   #21
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Quote:
Originally Posted by cucamelsmd15 View Post
...
Also, one thing I havent seen mentioned yet, what kind of condition are wheel bearings in?
Wheel bearings are probably pretty good. OP is running an '06 STi. The front wheel bearings are the one thing I whish Subaru implemented on the '04 too.
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Old 06-16-2011, 08:21 AM   #22
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Quote:
Originally Posted by Web Foot STi View Post
Wheel bearings are probably pretty good. OP is running an '06 STi. The front wheel bearings are the one thing I whish Subaru implemented on the '04 too.
While the 5x114 hubs are better, I know of at least one local who goes through a set every few track events. Granted, he is running slicks, but they can and do go bad...
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Old 06-16-2011, 08:24 AM   #23
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^OK. I just learned something. I like learning the easy way.
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Old 06-16-2011, 08:41 AM   #24
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I've been on 245 slick with a 2640 lb car racing a weekend a month or so... my 5x100's have held up for almost 20 events :P

anyway - defo sounds like you just need more air flow. All the theory in the world wont predict exactly what you're experiencing via the web. take what's mentioned above, internalize it, make changes and get back out there.
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Old 06-16-2011, 08:49 AM   #25
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Why do you think it's the fluid boiling?

DS2500s will fade way before ATE blue will boil, fresh or old.

Knock-back maybe?
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