[Wera313]

The braking system is the Achilles heel for my ‘22 SS 1LE. I’m hoping you all have ideas to cool or otherwise upgrade brake system to eliminate overheating.

To date I’ve been using RBF660, switched to Girodisc hats and rotors, PFC race pads, titanium backers and CTS-V performance ducts. Last weekend my fluid boiled at the end of two 25 minute sessions. Ambient temperatures were in the mid-high 80s at the time.

I lost pressure going into a turn. Brake pedal went half way before pressure built. I made it through the corner and then was able to stop off-line. In the paddock I could see where fluid had boiled out of the front calipers. There are AP temp stickers on the calipers. Both read just shy of 500 degrees. The brake fluid was changed within the last two months.

Any ideas on fixing the overheating problem? My planned next step is having a local race shop build a custom ducting system. Other option would be converting to AP brakes.

[Baddawg53]

I can't really weigh in on the technical side of this, as to why it's happening, but I use titanium shims to help keep some heat out of the calipers. Seems to help along with the deflectors.

Edit: Sorry, missed the part about you already had the shims...

[N Camarolina]

This is odd. Most of us don't have problems with overheating the brakes. A few thoughts:

1) Is your track unusually punishing on brakes (lots of braking, followed by no long periods of non-breaking to help cool)?

2) Are you running PTM mode below Sport2 and abusing the stability control system (rear brake activation pumping extra heat into the brake fluid)?

3) Any chance your RBF is accumulating too much moisture? Most of us use Castrol SRF because it has high dry AND wet boiling temps

4) If using RBF, do you bleed the calipers after each event? Maybe you're destroying the fluid in the caliper.

5) Is your SS 1LE stock engine, or have you increased power? Increased power will of course lead to higher speeds at the ends of the straights, which will require increased brake rotor and caliper size to dissipate the added energy.

[eimarshall]

Technically the girodisc rotors are lighter, so they have less mass to absorb the heat. Theoretically they have more vanes and should cool faster, so maybe that is moot.

I don't know you're driving style, but as Camarolina mentioned, ptm modes can have an effect. Additionally, the more time you spend on the brakes, the more heat the accumulate. This may sound obvious, but what it means is that a sharper, faster brake application will actually contribute less heat to the braking system than a slow trailing on and off of the brakes.

Lastly, rbf660 actually has a lower wet boiling point than rbf 600. The dry boiling point may be higher, but the moment you open that bottle, I'd argue the dry boiling point goes out the window. I would flush a full liter of SRF or RBF600 through my system if I experienced what you describe, just to make sure I got ALL the boiled fluid out.

Just my $0.02. I hope that's helpful.

[cdb95z28]

Originally Posted by Wera313

The braking system is the Achilles heel for my ‘22 SS 1LE. I’m hoping you all have ideas to cool or otherwise upgrade brake system to eliminate overheating.

To date I’ve been using RBF660, switched to Girodisc hats and rotors, PFC race pads, titanium backers and CTS-V performance ducts. Last weekend my fluid boiled at the end of two 25 minute sessions. Ambient temperatures were in the mid-high 80s at the time.

I lost pressure going into a turn. Brake pedal went half way before pressure built. I made it through the corner and then was able to stop off-line. In the paddock I could see where fluid had boiled out of the front calipers. There are AP temp stickers on the calipers. Both read just shy of 500 degrees. The brake fluid was changed within the last two months.

Any ideas on fixing the overheating problem? My planned next step is having a local race shop build a custom ducting system. Other option would be converting to AP brakes.

Lots of good points made by eimarshall and N Camarolina.
As mentioned RBF600 is not enough. Castrol SRF, Brembo HTC64T or Endless 650 should be on the list.

What do you mean concerning the above statement in red? If you mean that some fluid escaped the bleeder, that is because when you finish bleeding there is a vertical column of fluid still trapped within the bleeder. Unless the bleeder was not tight enough. But most likely it's because you must evacuate that fluid otherwise as it heats up it will push out. Remember the bleeder seals at the bottom at a taper, below the threads. Any fluid left within the bleeder will push out of the threads and/or the top of the bleeder. This has nothing to do with boiling, though excessive heat will quicken the chance of that leftover fluid finding its way out.

Driver technique goes a long way to proper brake management. Long drawn out braking events do not do any favors to the brake components. Track layout matter also. Any other Gen6 drivers at the same track having issues?

Which PFC pads are you running? Too aggressive of a pad generates more heat. Choose appropriately there. Some guys buy more pad than they really need.

Cooling issues on the Gen6 SS 1LEs are rare. Go back to basics.

[5.M0NSTER]

Great points by everyone so far. Curious about 2 things.

Which PFC pads do you run, and where did you source them?

Technique wise, is this a particularly hard track on tires/brakes? Using the brakes only to transfer weight and bleed just enough speed is key.

[Christian1LE]

Bad fluid, moltul sucks. Go with Castrol srf.

[Osbornsm]

Originally Posted by Christian1LE

Bad fluid, moltul sucks. Go with Castrol srf.

<-- boiled Motul too


SRF ftw

[SCCAForums]

SRF is great, Endless 650 is my choice... for a bit firmer pedal feel.

Best regards,
Dave

[5.M0NSTER]

I have run SRF for 3 seasons and about 15 track days without changing. No hit of soft pedal. Love this stuff and that it’s wet boiling point is so high. Does endless repel moisture like SRF does?

[DaveC113]

I'm running Brembo HTC64T and Ferodo DS3.12, Blackwing CT5V control arm deflectors, no issues at all.

[5.M0NSTER]

Hawk DTC60s, factory deflectors, SRF. Also no issues.

[SCCAForums]

Originally Posted by 5.M0NSTER

I have run SRF for 3 seasons and about 15 track days without changing. No hit of soft pedal. Love this stuff and that it’s wet boiling point is so high. Does endless repel moisture like SRF does?

Endless 650 is used in F1, WRC and Dakar... it is also mixable with Dot 4, whereas SRF is not.

It's not that SRF has a 'soft pedal'. I've used it for years... it's just that the 'pedal is less firm' In my experience, and that's why I made the change to Endless 650 a few years back.

I would not hesitate to run any race car with SRF or Endless 650.

As for brands I wouldn't use, the 'standard Motul Dot 4 and the Redline Dot 4 Brake Fluid... absolutely some of the worst Dot 4's out there... (and I'm a Redline Fan for their other lubricants).

PS... I'm Blackwing Deflectors, G-Loc Brakes, Endless 650 and no issues for 3 years in 6th Gen Camaro. (Prior SS 1LE Deflectors before BW were available, still zero issues, no additional brake cooling).

Best regards,
Dave

[carguy55]

SRF is used in F1. Make sure you use a new bottle and bleed the ABS. I use SRF, DTC60s and 70s, CTS-V ducts, small splash shields. I was using Ti shields but rebuilt calipers with vented pistons so don't need the shields anymore. I have 80 track days included some in the Texas summer heat.