[Osbornsm]

How do i prevent the SS 1LE from boiling its Racing Brake Fluid?
I have just returned from a track day at a local venue.

1. Brakes only lasted 15 minutes before boiling the fluid
2. Brakes were bled 2 days before the event with Motul RBF600
3. Pads are Raybestos ST-43
4. Temps:
- Ambient Temp: 90 F
- Rotors: 650 F
- Caliper: 450 F
- Oil: 240 F
- Trans: 220 F

Brake pedal behaved like this...
Great, Great, Great, Great, Ehh, FLOOR


Autobahn Country Club - Full: 3.56 miles / 21 turns

== Hot Lap video ==

[Badgerbimmer]

Castrol SRF

[Mountain]

Hmm, I've heard of people using RBF600 without issue.

Personally, I run Castrol SRF and stock pads. No issue all day long on my hottest track day: 90F+ sunny at Grattan.

I'll check your video on your braking later.

[Ichabod]

who did the fluid change?

[ZL1 1LE]

Was it an unopened can?

[JeromeS13]

As I mentioned on your FB thread, you're liking using too much brake, too soon. I'm using Motul RBF600, OEM pads, and RE-71Rs.

Blue line is braking. Red line is longitudinal acceleration. Over 1 G of braking and zero fade after 15-20 minute sessions.

[Osbornsm]

Originally Posted by Ichabod

who did the fluid change?

Dealer did the initial fluid swap to Motul RBF600.

I did the bleed 2-days before the event.

[Osbornsm]

Originally Posted by JeromeS13

As I mentioned on your FB thread, you're liking using too much brake, too soon. I'm using Motul RBF600, OEM pads, and RE-71Rs.

Blue line is braking. Red line is longitudinal acceleration. Over 1 G of braking and zero fade after 15-20 minute sessions.

Hmm... my telemetry is not this accurate.
But i'm just lookin for advice.

[Provoste]

RBF 600 stated wet boiling point: 420f. No surprise you encountered brake fade w/ 450f caliper temps. Sounds in line with what I've heard about ST43's: they generate a lot of friction and heat. Sounds like not the ideal pad for a bullring like Autobahn (yes I've driven the track). I don't doubt JeromeS13's assertion that your're likely braking a bit too much as well.

SRF is a band-aid that will likely keep heavy brake fade at bay (517f wet boiling point), but will not address the underlying issue.

[Mountain]

I’ve been around Autobahn quite a bit, but not in my 1LE. It looks to me like a lot of braking at or before the 3-board until past the 1-board, sometimes all the way into the corner. You should be able to push a 1LE later than to he 3-board and you don’t need to ride the brakes into the corner. Get off the throttle, hit the brakes (hard), settle the car and get into the corner.

If a Lemons car in 100*F sunny weather, riding on near backing plates for 10 laps can manage, a 1LE can.

What modes are you running?

[TrackClub]

ST43 pads are the culprit here given all the other variables. They put out a lot of heat.

Unless youre chasing that last tenth under braking and dont mind rebuilding your calipers often: simply switch back to stock Ferodos and your issue will be fixed.
Stock Ferodos have much lower torque and are gentle heat wise even under hard and extended use regardless of track venue layout.

I use them and think they are well matched to the tires and cooling parms of a stock car. The only disadvantage is they wont last as long as ST43s. But there is never a free lunch

[bpang1234]

Originally Posted by TrackClub

ST43 pads are the culprit here given all the other variables. They put out a lot of heat.

Unless youre chasing that last tenth under braking and dont mind rebuilding your calipers often: simply switch back to stock Ferodos and your issue will be fixed.
Stock Ferodos have much lower torque and are gentle heat wise even under hard and extended use regardless of track venue layout.

I use them and think they are well matched to the tires and cooling parms of a stock car. The only disadvantage is they wont last as long as ST43s. But there is never a free lunch

Yeah I caught my "normal" 4-pot front brakes on fire with the Hawk HPS 5.0 pads. After switching to the 6-pots and the stock Ferodo pads, they have been far more capable and reliable.

[Norm Peterson]

Does "bone stock" here mean that no efforts had been made to improve brake cooling (ducts or deflectors)?


On edit, was the caliper temperature 450F or 500F? This thread and your other one in the 'Ask Al' section aren't lining up . . .

Originally Posted by Osbornsm

4. Temps:
- Ambient Temp: 90 F
- Rotors: 650 F
- Caliper: 450 F
- Oil: 240 F
- Trans: 220 F

Originally Posted by Osbornsm

• Fluid: Motul RBF600 bled 2 days before event
• Pads: Raybestos ST-43
• Caliper Temp = 500 F (after cooldown)
• Rotor Temp = 650 F (after cooldown)

• Norm

[TrackClub]

Originally Posted by Norm Peterson

Does "bone stock" here mean that no efforts had been made to improve brake cooling (ducts or deflectors)?


Norm

That's indeed the case re my car. Stock pads, albeit less torquey than others (very similar to xp10 imo) run very cool and dont even require dot4 fluid per se. I run Wilwood HiTemp dot3 Racing Fluid with them and NEVER got a slightest fade regardless of ambient temps or venue type. Even tho, i have a tendency to point the car with brakes and trailing them in deep. Of course spending more on dot4 is never a bad idea, but it would seem that SRF is the only fluid capable of handling higher torque pads on these cars without cooling mods.
This may be venue dependent of course.