Cooking Fluid..

[2jayzgte]

I thought I'd try here in the last 3-4 years or so I have moved to a full race slick at the track but in the last 2 I have been cooking brake fluid like no bodies business.

I have ducting to the rotors I have tried AP Racing Motul RBF 600 and 660 and have cooked the lot..

Frustrated yes I am I was told by the guys who looked after my car upwards of 2 years ago that this would happen I didn't want to believe it but they were right damn them..lol...lol..

Now what I would like from you guys are some possible solutions without spending huge $$$$$$$ if there is one.

Titanium Brake Shims yep they worked for 1 session but after that the fluid boiled.

I run the TRD 4-pot calliper with TRD slotted 323mm rotors in the front and the Factory 2-pot Rears with the 323mm rotor.I have have used a combo of pads over the years Hawk HP Pluses and HT-10's and TRD Red's front and rear to no avail.

I have a solution in mind but I'm just wondering if anyone else out there had any thoughts they may want to pass on before I move and go ahead with the thought I had.

PS I only cook fluid on the track fast road running and whatever else fast I do on the road the fluid I use holds up but without fail the last half dozen days at the track I've done its been painful watching me brake earlier and earlier just so I can get the brakes to last and get some laps in.

[Mr Ree]

Have you ever tried running a more aggressive pad compound on the rear to try and shift some of the bias that way, without having to go to a manual brake bias level adjuster?

My suggestion is water cooling, as once you have paid for the pump and lines, then its just tap water from then on so costs are a one-off affair.

I just brake a little bit less aggressively when on the track, in order to try and keep the temps under control, because as you mentioned, you can get more laps that way. I know its not going to help you set any PB's but I just prefer to do 8-10 laps at 90% than 4-5 due to pushing the brakes too hard.

Did you ever find out if the TRD callipers have the same applied force as the factory 4pots? I recall us discussing it with Dave earlier in the year in taupo, and we were saying that there are others running the 4 pots that are getting better braking life than your set up, and we were pondering whether or not they did the same job.

Swapping over to some factory 4 pots might eliminate some possibilitys in regards to seeing if the bias is the same. Its possibly your TRD callipers require more fluid displacement than the normal 4 pots, and as such, theyre stealing valuable fluid, clamping, and bias from the rear.

Just a theory...

[Stott69]

Whats your ducting system? Is it straight and unrestrictive? Maybe a inline fan to push air on the brakes during lowwer speeds?

[Mr Ree]

Whats your ducting system? Is it straight and unrestrictive? Maybe a inline fan to push air on the brakes during lowwer speeds?

The fan would just become a restriction when airflow was needed most though, mate.

[Grrrrrrr!]

Better ducting. What are you doing to get hot air away from the brakes?

[Stott69]

Whats your ducting system? Is it straight and unrestrictive? Maybe a inline fan to push air on the brakes during lowwer speeds?

The fan would just become a restriction when airflow was needed most though, mate.

Not if set up right, or whats the point of a turbo? A fan would be able to push air down the ducting at lowwer speeds when air force on the intakes is low. I'm a hvac tech so deal with fans n ducting day to day, selecting the right ducting and fan is the same in a way as turbo n intercooler.

[Mr Revhead]

Manual conversion

[Mr Ree]

Whats your ducting system? Is it straight and unrestrictive? Maybe a inline fan to push air on the brakes during lowwer speeds?

The fan would just become a restriction when airflow was needed most though, mate.

Not if set up right, or whats the point of a turbo? A fan would be able to push air down the ducting at lowwer speeds when air force on the intakes is low. I'm a hvac tech so deal with fans n ducting day to day, selecting the right ducting and fan is the same in a way as turbo n intercooler.

We arent talking about a ceiling space with room for 250mm dia spiraflex and a large axial fan though, mate

Ive worked for years as an HVAC commissioning enginner, and having a small fan inline on the small inlet pipe of the brake ducting is going to restrict the airflow at all times, regardless of size/fan design/pitch etc. Which = less overall airflow, which means more heat.

Having it on the extract side is another story, as it would help shift air without adding unnecessary restriction to the inlet side, but sadly, we all know there isnt enough room to install the required shroud and fan setup inside the wheel well

[fxgt race]

Maybe a water cooling setup is probably the only thing you could do, washer bottle and piping , switch on brake peddle, needs a sprayer nozzle on to the disk.

[Stott69]

Fair enough. OT but which crowd did/do you work for?

[gasman]

my experience with extreme brake setups is pretty limited, but what are the risks with running water cooling on the brakes?

is it even allowed on the tracks? i know at some drag tracks they dont let you even spray the intercooler and stuff like that.

also what about cracking the disc since your effectively quenching a red hot disc?

[Adoom]

Just brain storming....
Would it help to use a larger reservoir, that holds more fluid? But I suppose the fluid is only boiling in the caliper...
What about putting water sprayers in the duct?

[Adoom]

Well.... I typed that FAR too slow. No one had replied when I started

[fxgt race]

You spray a mist on to the rotors, it won't crack the disks, it will evaporate as soon as it hits.

[Mr Ree]

The setups I have seen spray a jet of water (through an tube the size of a brakeline), rather than a mist, because as you say, the water turns to steam before it even makes contact with the metal rotor, and you need quite a bit of water to make a substantial temperature drop.

The main thing is working out the quantity you need to spray after each brake pedal application, so a timer is needed to adjust the volume of water, depending on what track you are using.

[fxgt race]

As I said it will evaporate when it hits the disk, not in mid air, theres no need to over complicate the concept with timers and flow rates. Its a simple setup.

[RS13]

Manual conversion

Its' automatic? With little or no engine braking, you're asking pretty big things of your brakes on the track.

[Adoom]

As I said it will evaporate when it hits the disk, not in mid air, theres no need to over complicate the concept with timers and flow rates. Its a simple setup.

Argeed. Even with a timer, I think it would have to be on for 90% of the time anyway. May as well do away with the timer and have an on/off button in the car.
Windscreen washer pumps, wire, cable ties, and sprinkler misting nozzles are CHEAP. You could build a test system for almost nothing.

[Mr Revhead]

I seem to recall the racing trucks spraying water up through the cooling vanes internally on the discs. Spraying water in any way onto the braking face of the disc doesn't seem that smart to me. Most certainly not with windscreen washers! It's unlikely you could mount them in a place to do that with out them melting and without water going everywhere. They will need to be very close to the rotor

[2jayzgte]

Manual conversion

Its' automatic? With little or no engine braking, you're asking pretty big things of your brakes on the track.

I still use the gearbox regardless.

Water Sprayers hmmmmm...something to think about sounds fiddley to me but I have noticed V8SC's are using this.

Thanks for everyones feed-back I think I'm going to delete the ABS for starters and go with a bleed valve see if we can't squeeze some more pad wear out of the rears.

Yes to those who have asked I have also used Hawk HT-10s in the back if I'm honest I think those Hawk pads with there aggressive biting qualities while giving very good intial bite jack the brake temps quicker I could be wrong but I'm just speaking from experience.