[Osbornsm]

Had my 2nd track day with the SS 1LE @ Autobahn Country Club - Full course = 3.56 miles.

- Hot-lap time: 2:50.62
- Rotor temp (after cooldown): 718 F
- Caliper temp (after cooldown): 440 F
- Oil temp = 240 F

This is significantly better than the last track day where I boiled the Motul brake fluid and went high-speed farming.
...also shaved another second off my time yesterday.


Reason the brakes survived this time...

1. Upgraded to Castrol SRF
2. Added titanium backing plates
3. Added brake ducting all the way to the splash shield

Summary

Feel free to add opinions but be prepared to defend yourself with facts.


<<YouTube link of my PDR for the hot-lap>>

[kropscamaro16]

nice !! how did the new fluid and what brake duct kit do you have>



stock pads or>?

[Osbornsm]

Brake ducts are from here...
https://garagetherapync.com/product/1

And used Castrol SRF fluid. Only on the 4th session of the day did the pedal start to get "long"

[NickyRacerBoy]

240 oil temps are nice and low. 80 ambient temps I see 270.

[TrackClub]

What pads please?

[Osbornsm]

Mfr. = Porterfield

Pads = ST-43
Front and Rear same compound.

[TrackClub]

Originally Posted by Osbornsm

Mfr. = Porterfield

Pads = ST-43
Front and Rear same compound.

Here's your culprit. If you got long pedal this means you've started to boil SRF...ouch! This means I'd at least bleed it asap, if not flush it completely. This also means your calipers will likely get fried soon a la Nicky Bobby's recent story. So get ready

PS Congrats on your PB! Maybe try Ferodos and gain trail braking ability (which is extremely difficult with ST43s - if not outright impossible - at least with my skill). Provoste demostrates this very well in his vid at Barber chasing down 2 very well driven GT3s. Using stock pads. Food for thought, that's all. In any case: have bags of fun! Cheers!

[Osbornsm]

Originally Posted by TrackClub

Here's your culprit. If you got long pedal this means you've started to boil SRF...ouch! This means I'd at least bleed it asap, if not flush it completely. This also means your calipers will likely get fried soon a la Nicky Bobby's recent story. So get ready

PS Congrats on your PB! Maybe try Ferodos and gain trail braking ability (which is extremely difficult with ST43s - if not outright impossible - at least with my skill). Provoste demostrates this very well in his vid at Barber chasing down 2 very well driven GT3s. Using stock pads. Food for thought, that's all. In any case: have bags of fun! Cheers!

Well that's not good news with nearly boiling Castrol SRF.
There not any more brake cooling options I'm aware of for the SS 1LE.


I had flushed the brake fluid the weekend before the event. So it was brand new SRF.


COULD YOU ELABORATE on what a fried caliper entails?

[TrackClub]

See Nicky's thread below. Basically seals go and pistons no longer operate as intended.

[TrackClub]

I should add, that this issue seems very much venue dependent. Ive run ST43s at 3 different tracks with zero issues at Mosport which only has 2 harder brake zones with the the rest of corners being fast sweepers only requiring a gentle touch to point a nose in, or even just a lift. However, at the other 2 venues, which demand hard braking and offer short straights for cooling I'd boil the fluid in a single session.
The pedal would get progressivly softer and eventually go to the floor. Once that happens it recovers between sessions, but the issue comes back much quicker in subsequent sessions, suggesting the fluid gets permanently compromised. BTW i ran Willwood not Castrol, but i dont think it would matter much end result wise. Cheers!

[RUQWIKR]

Originally Posted by Osbornsm

Well that's not good news with nearly boiling Castrol SRF.
There not any more brake cooling options I'm aware of for the SS 1LE.


I had flushed the brake fluid the weekend before the event. So it was brand new SRF.


COULD YOU ELABORATE on what a fried caliper entails?

On "fried"...each caliper piston bore of this design has an outer dust boot / seal, a piston in the machined bore, and a pressure seal / o-ring. Typically, the outer dust boot / seal will start to crack, breakdown from a higher temp than it was validated to take. Dust and dirt can get past it more easily then which can lead to scratched piston bore walls and / or damage to the pressure seal.

If the pressure seal gets compromised, either by excess heat and / or dust and dirt, you then will have a pressure leak, anywhere from very minor up to a loss of brakes.

I ran a year on stock J6M (SS 1LE) brakes with stock pads and was not easy on brakes. Never hurt a dust seal or inner seal due to excess heat. I ran a year with J6H (ZL1) brakes on my SS 1LE...same thing...no issues on stock pads.

The J57 CCB front calipers are the same as the J6H ZL1 (not talking paint color) except for one key difference: they have vented pistons to keep heat away from the seals. Like the J6H pistons, the main body of each piston is aluminum, but, the vented tops are steel. Top pic...middle pic is typical J6M / J6H style of pistons. Those are the pressure seals that go in the machined groove in the piston bore. Examples of dust seal / boot is the lower pic - of course, only two sizes vs. the three on our fronts.

[Osbornsm]

Originally Posted by RUQWIKR

"fried"...each caliper piston bore of this design has an outer dust boot / seal, a piston in the machined bore, and a pressure seal / o-ring....

Thank you very kindly for the info!!


Although i ran my Nissan with 4-piston calipers until the dust boots evaporated. That ran fine?


Preventative maintenance i suppose huh.


Thoughts welcome!

[TrackClub]

Excellent detail thx for posting it RUQWIKR.

Personally I've learned a long time ago that more heat = bad news = higher costs. While running better fluid will facilitate running higher torque pads, it does nothing regarding the whole area (not just calipers!) being subjected to much higher temps.

Ive also done 2 full seasons thus far, about 30 days on stockers with zero issues regardless of venue type, ambient temps, or length of sessions (up to 45mins) running cheap Willwood 570 fluid no less (bleeding it every 5 days or so). No soft pedal EVER. And my calipers still look brand new.

[TrackClub]

Originally Posted by Osbornsm

Thank you very kindly for the info!!


Although i ran my Nissan with 4-piston calipers until the dust boots evaporated. That ran fine?


Preventative maintenance i suppose huh.


Thoughts welcome!

When i ran Essex AP Racing kit on my Vette with DSUNOs we had to rebuild calipers every 2 seasons max as pistons would stop releasing properly and pads would drag. I have no idea if any of it can potentially lead to a complete failure, or just PITA and extra cost.