stujelly

I am trying to find a good brake fluid to use on my 11 gt3.rs. Currently I am using Castrol SRF with the PFC 08 pad and slotted rotors. I was at thunder hill this last week for 2 days and at the end of each day I started to experience some brake fade, and the outside temp was about 80 degrees so not a hot day. The brake fluid was flushed and bled 2 track days before and the pads are at about 50 percent.

Sooooo I thought maybe it is time to change brake fluid manufacturers so I found this chart on the internet and it shows the SRF has the highest boiling point. What am I missing and I was just curious what others are running.

Thanks

Arranged by wet boiling point:

DRY:401F -- WET:284F --- DOT3 MINIMUM
DRY:550F -- WET:284F --- PERFORMANCE Friction Z rated
DRY:550F -- WET:284F --- FORD HEAVY DUTY DOT 3
DRY:570F -- WET:284F --- WILWOOD 570
DRY:572F -- WET:284F --- US Brake / AFCO Racing 570 Gold
DRY:577F -- WET:300F --- Brake Man
DRY:527F -- WET:302F --- AP RACING 551
DRY:446F -- WET:311F --- DOT4 MINIMUM
DRY:527F -- WET:347F --- VALVOLINE SYNPOWER DOT3 & DOT4
DRY:543F -- WET:349F --- Endless The truth DOT 4
DRY:500F -- WET:356F --- DOT5.1 MINIMUM (GLYCOL BASE)
DRY:500F -- WET:356F --- DOT5 MINIMUM (SILICONE BASE)
DRY:536F -- WET:392F --- ATE SUPERBLUE/TYP200
DRY:601F -- WET:399F --- BREMBO LCF 600 PLUS
DRY:590F -- WET:410F --- AP RACING Super 600
DRY:617F -- WET:413F --- Endless RF-450
DRY:626F -- WET:417F --- WILWOOD EXP 600
DRY:572F -- WET:421F --- US Brake/AFCO Racing Ultra HTX
DRY:585F -- WET:421F --- Earl's Hypertemp 421
DRY:593F -- WET:420F --- MOTUL RBF600
DRY:610F -- WET:421F --- NEO SYNTHETICS SUPER DOT 610
DRY:610F -- WET:421F --- PROSPEED GS610
DRY:622F -- WET:424F --- Endless RF-650
DRY:620F -- WET:425F --- COBALT SUPER XRF [seem to no longer be available]
DRY:590F -- WET:518F --- CASTROL SRF

911rox

Stu, as your figures show, there are some fluids out there with slightly higher dry ratings but brake fluid deteriorates in performance as it absorbs moisture and the SRF clearly outperforms the rest overall... If you flushed very frequently, you may benefit from one of the others as its wet rating won't come into play as much... My shop put me on SRF and i have no braking probs on oem pads with heavy braking from 210 to hairpin turn speed in two sections of track... At another track, we complete 35-40 laps without breaks, with lots of braking zones...

Could it be missing ducts, blocked ventilation or a similar problem adding to your fading issue?

GT3DE

Its not the fluid, its the steel rotors.
pccb - no fade.
I have same setup as you now - SRF, PFC slotted, 08 pads. I have run this setup exclusively in 2012 on both cars - 20+ track days in 2012.
For over 10k track miles I used stock pccb in 2010 and 2011.

Here is my analysis of the two different systems:
* the stock pccb is unreal awesome on the track, but is expensive.
* the pfc slotted steel is not unreal awesome on the track, but is cheaper.

911rox

Or change to the 34mm thick friction rings to increase thermal capacity??....

Izzone

I think u either had old fluid or air in the system after the bleed

Reter, Erik and I use srf, middle of summer at Sebring and after two events there is no way it boils

TRAKCAR

Great post Clarke,

You are one of the few who really tests both.

Can you give more detail?
How's the feel differ? Do you feel less weight? Do they stop the car better, or just fade free longer? How do they hold up in real life? Can you give some durability numbers on PCCB? Some people run on 10 or so track days a year, so if they last 40 track days it might be worth it to them.

I can't afford the PCCB, so moot point to me as I am very happy with the same steel brake setup you mention on your car. With RA1 grip there is no problem ever for me in the worst heat on the worst tracks. But with Pagid pads, or oem fluid or R6, we can boil the fluid. Forget slicks.

NJ-GT

I have used Castrol SRF for 8 years straight, before that I ran Motul RBF600, ATE SuperBlue, ATE Gold.

But as soon as I switched to steel rotors in the Fiat, SRF boiled in the front axle on my 1st track day on steel rotors, despite of running MPSC tires. I went back home, switched to Endless RF650, put a set of sticky Hoosiers, and ran my 2nd day with no pedal softening, at an almost 4 seconds faster pace, with less cooling by running wider tires. RF650 exceeded my expectations. This was Homestead on a very hot day.

Without flushing (because I did not have a case of RF650 I had ordered weeks before), I went 2 more days to Sebring, and went through the weekend on what has been the hottest day I have driven at Sebring, this was the NASA event in late March. I ran 3 sessions on street tires, then switched to brand new slicks for 4 more sessions (1 on day 1, 3 on day 2). So, now I have converted to RF650.

I put a set of brand new 997 GT3 Cup front rotors in my Cayenne with RS29 pads (left over parts from 4 years ago), the pads were too tight. I took a 600 miles trip last week. I flushed the fluid with RF650 as well, as I got my case. During bedding-in and during the trip the brake pedal stayed with the same pressure. Half way through the trip, the SUV develop vibrations on the front axle, I stopped and the brakes were red hot, the pads were too tight and would not retract fully. As a consequence, I cracked one of the rotor 1/2 way through the entire surface, so they really overheated, my RS29 have the white finish they get when reaching high temperatures, but brake fade was not a problem. So, I'm now more converted to RF650.

Add bigger cooling ducts to your GT3, the car needs them anyway.

AudiOn19s

If you've got the bottle of SRF I'd be curious how old it was.

I had a bad experience with one of the fluids on your list (not SRF) that's generally seen as a VERY good fluid. I was soo disapointed I contacted the manfacturer because I couldn't even make a 20 min DE session without boiling the fluid near the end of the session. Despite the bottles I got being fresh and sealed properly they were old stock of the fluid. The manufacturer told me that I should not have been sold such old fluid as even when sealed it can go bad from age. They sent me replacement fluid that was fresh and I installed it in the car and all of my problems went away. I always check manufacture date after that experience.

NJ-GT

Per your own words at Monaco:

"I spoke to 2 Porsche mechanics. 1 in Dutch from Team Bleekemolen.

PCCB is mandatory and they both said PCCB blows:
-too expensive
-last only 3 weekends if that
-They waste a day bedding them in.
-Both said go steel!

All yellow calipers are completely discolored to Bronze and orange"

In my experience with PCCB and later CCB in the Fiat, they are worth it. I have run them for almost 9 years straight and I like them for the sole reason of being so much lighter.

In the 2010 GT3 RS, PCCB save 46 lbs, which is the biggest saving between steel and CCB on any street car, unsprung weight. This is just the consequence of VW running the same size brakes for steel and PCCB for 2010-2011 in the GT cars.

Any car I buy in the future must have CCB/PCCB.

PCCB tolerate more temperatures, they last 2 times longer than premium steel rotors (PFC, AP, Brembo Racing) and 3-4 times longer than stock rotors. On street only use, they last forever.

PCCB wear based on weight, and when they reach minimum weight, the surface gets abrasive, so they sand down the pads quickly. They cannot make contact with debris or when mounting wheels, or you would chip the edges and cause early delamination.

On your car with your driving and RA1, you should get 40 hours of track time out of them, replacing pads when they are 1/2 worn out (thickness), and doing proper cool down when sessions are over.

My Fiat CCB rear rotors are as good as new, close to new weight, front ones are at 40% life left, 12,000 miles on them, 25 track days, multitude of autocrosses, and experimented with 9 different pad compounds.

You should try the PCCB with PFC-08, the bedding-in procedure on PCCB requires 50 iterations of go/almost-stop from 80mph down to 20mph, I have it written somewhere, makes a huge difference. The best pads I have used with CCB are RS29 and RS19, but PFC-08 seem to be a better pad. The Porsche Motorsports pad uses the hardest Pagid compound (RS15), and kills rotors early, despite the great stopping power, this is why SuperCup teams replace PCCB rotors so often.

The same RS15 compound is being used by Fiat in the F430 Challenge since 2008 and the 458 Challenge, they are replacing front CCB rotors every other race, every 8-12 hours on the front, and twice as much on the rear CCB.

So, stay away from stock pads, stay away from PMS pads, either run RS19, RS29 or PFC-08.

A new set of steel rotors would be in the $3k range (the stuff you use), selling the PCCB is in the $5k range probably a little more given that they only have 800 miles, I would sell them at $6k.

Steel rotors are more progressive in feeling, PCCB/CCB more on/off feeling.

Can you feel the weight difference? I do, by a lot, just switching to steel in the Fiat, made my steering heavier, the car is less tossable than it was before, big difference. Would I go back to CCB? Of course, but to a custom size that allows me to run 18" wheels.

...and there is the cherry on top. Once you're done with PCCB, the vastly longer lasting 3rd Generation CCB have been out for a few years, and tested fully in FIA GT1, GT1 cars are faster than ALMS-GT2 and close to the ALMS-P2 for lap times, monster Aero and 600 Hp. This 3rd Generation CCB is that BMW will start offering in the new M6, Brembo has offered them for many years, and this is the stuff StopTech wanted to release 3 years ago. This 3rd Gen rotors is exactly what you get from MoviT, and Movit makes a set of replacement rotors that allow you to reuse your hats and save a ton of money.

If I were you, I would run PCCB on PFC-08, if the feeling is not good, switch to RS29, then switch to Movit. Ask SavyBoy when was the last time he replaced his MovIt rotors.

Izzone

Wrong

All four corners less than $1,500

There is no reason to use PCCB on a DE car, unless you are made of bannanna picker money

NJ-GT

Forgot you guys buy OEM cheap turbo rotors for the back, and don't include the price of the hats for the front. Where do you get free front hats?

Izzone

The hat takes the rotational load of the brake torque on PFC, so unlike all other solitions you just have to replace the rotor. The hat and hardware can be reused. Based on this I just use rotor cost as replacement

Rear rotors last forever if you drive with all the stupid computers off......turbo work fine

mdrums

I've been using Pro Speed RBF 683 and have not boiled it. Indy, NASCAR lots of ALMS and Rolex teams have switch over to this fluid.

I found SRF to feel more mushy all the time and sometimes I had thought I boiled it but really didn't. Pro Speed have less oxygen in it, it's the least compressible fluid on the market and it really good for your seals. I'm completely sold on Pro Speed 683

Mvez

Endless RF650 is the real deal. I've used everything, and the Endless lets you go longer without bleeding (it absorbs water at a slower rate), and pedal feel is rock solid. Half the price of SRF.....try it, it rocks.

TRD0524

On most proper race rotor setups you can use the hats and do not have to replace them (AP, Brembo, PFC, Alcon, Endless). Some designs allow the hats to last longer than longer due not stressing the hats so much. In professional motorsports, the AP design is the most popular because it has almost 0 stress to hats by keeping the "float" on the brake disc and does not carry any of the of the extra weight of the PFC mounting system.