[mr_lab_rat]

I'm new to tracking my car but I can already tell it's gonna be my new hobby

My first day was on a small track that's very hard on brakes. I noticed some fade once we started picking up speed (200kmh down to 60kmh hairpin).

I was on stock brakes with fresh OEM DOT4 fluid.

I checked rotor temps and I was up to 300C (572F).

Here are my questions -

1. Where should I measure temperature? On the rotor? Caliper? Where on the caliper?
2. How hot is too hot (for stock brakes)? At what temp will the calipers turn green?
3. In which order would you upgrade: pads, fluid, ducts

[5.M0NSTER]

Yes sir, you know once you're hooked!

As for your questions:

1) Measure both at the rotor, and at the center of the caliper (Or hottest point of caliper you can find). The rotor temp is good to know so you can choose the right pad, the caliper temperature in turn tells you what temps the brake fluid is exposed to.

2) Stock fluid is not made to take much over 300F, stock pads will fade at ~800F

Castrol SRF, Motul 600 or similar take your fade resistance when dry (no moisture from environment absorbed into the fluid) to about 600F

Proper track pad will take 1300-2000F before fading.

3) Pads and fluids at the same time, ducts after. You'll be good for a while with high temp pads and fluid. Ducts come later once you're rally pushing into the brake zones, and on throttle enough to minimize cooling off time between brake applies.

BIG HINT: It's also important to maintain the right braking technique ONCE you have the high temp pads AND fluid. Brake LATE AND HARD! Don't ride the brakes till the apex when you already slowed down. This is the fastest way to overheat your brakes.

[mr_lab_rat]

Originally Posted by 5.M0NSTER

Yes sir, you know once you're hooked!

As for your questions:

1) Measure both at the rotor, and at the center of the caliper (Or hottest point of caliper you can find). The rotor temp is good to know so you can choose the right pad, the caliper temperature in turn tells you what temps the brake fluid is exposed to.

2) Stock fluid is not made to take much over 300F, stock pads will fade at ~800F

Castrol SRF, Motul 600 or similar take your fade resistance when dry (no moisture from environment absorbed into the fluid) to about 600F

Proper track pad will take 1300-2000F before fading.

3) Pads and fluids at the same time, ducts after. You'll be good for a while with high temp pads and fluid. Ducts come later once you're rally pushing into the brake zones, and on throttle enough to minimize cooling off time between brake applies.

It;s also important to maintain the right braking technique ONCE you have the high temp pads AND fluid. Brake LATE AND HARD! Don't ride the brakes till the apex when you already slowed down. This is the fastest way to overheat your brakes.

I just had the fluid changed by the dealer (under the free maintenance coverage). They used ATE200 which is good for 536F dry but only 376F wet. But the fluid is less than 1 week old so it was probably still decent.

I will upgrade the pads and fluid before the next session.

Interesting on the technique, exactly opposite of what the instructors told us. But I understand the difference between dealing with street and race pads.

[Anthony1s]

Originally Posted by mr_lab_rat

I just had the fluid changed by the dealer (under the free maintenance coverage). They used ATE200 which is good for 536F dry but only 376F wet. But the fluid is less than 1 week old so it was probably still decent.

I will upgrade the pads and fluid before the next session.

Interesting on the technique, exactly opposite of what the instructors told us. But I understand the difference between dealing with street and race pads.

I know no one mentioned changing the brake lines, but I wanted to mention this anyway, because you mentioned brake fluid change covered under free maintenance... My dealer told me that free brake fluid changes are no longer covered once you change the brake lines.

[5.M0NSTER]

Originally Posted by mr_lab_rat

Interesting on the technique, exactly opposite of what the instructors told us. But I understand the difference between dealing with street and race pads.

Makes sense though. Instructors job is to make sure you survive your outing. The race driving techniques come later. It's everyone's instinct to hi the brakes at the 5 marker. But with proper equipment you aren't supposed to brake until you see God. Or the 2 marker as I like to call it

[moveswiftly]

Originally Posted by 5.M0NSTER

Makes sense though. Instructors job is to make sure you survive your outing. The race driving techniques come later. It's everyone's instinct to hi the brakes at the 5 marker. But with proper equipment you aren't supposed to brake until you see God. Or the 2 marker as I like to call it

The import of his advice is to brake only to slow the car down and to aid in rotating the front end into the corner (on turn-in). Lots of folks drag the brakes for elongated periods of time which just overheard the pads, rotors, and fluid - leading to brake fade.

A good instructor will help you figure out how to brake in a safe manner while leaving margin for error (I.e., they may ask you to brake at the 400 marker when you could brake at the 200 or 300). But their job isn't to get you the fastest LapTime - it's for you to learn, have fun, and be safe.

When you're solo and experienced you can experiment even more!

[Twt]

Originally Posted by mr_lab_rat

I just had the fluid changed by the dealer (under the free maintenance coverage). They used ATE200 which is good for 536F dry but only 376F wet. But the fluid is less than 1 week old so it was probably still decent.

I will upgrade the pads and fluid before the next session.

Interesting on the technique, exactly opposite of what the instructors told us. But I understand the difference between dealing with street and race pads.

All good advise...I prefer Motul 660. Once you decide on ducts, look at various threads which include my DIY version which costs under $100 and works.

[JoeP]

Do pads and fluids together in my opinion. If that is not feasible then fluids at a minimum. Just understand that track pads can behave differently than street pads.

You brake late and hard with race/track pads because they have a torque rise (i.e. they don't grab as hard the first few moments of brake application and then they kick in progressively). You want to get the heat in them and keep it up while not overdoing it. This happens very fast but it is noticeable if you've been on a long straight and haven't touched the brakes for a bit. If you're in a series of turns you likely won't experience the delay. Generally track pads like to be hot to work well. This is why driving them on the street is not ideal.

Of course not all pads are the same. Some pads will have much better "cold" bite (the brakes will still be hot of course but not like when you are under hard braking). So full braking is available more quickly.
My preferred pads in the past sometimes needed a little heat before they really grabbed. To that end if I was on a long straightaway I would often just touch the brake with my left foot to both set the pads and get a little heat in them. Also a good check to make sure you still have brakes. The car barely slowed. I liked those pads though because their torque rise was minimal (i.e. very consistent brake force throughout their working temperature) and I was never able to overheat them.

I do agree with both braking hard and braking early to start. That is how you will learn the behavior of the brakes but still be safe in case you are over the limit. Just take little steps to go deeper. Top priority is to make sure you are on your line though.



This illustrates my point about different pads having different torque rise rates, starting/stopping to work at different temperatures (the delay I mentioned is evident in the pads that work at higher temperatures)

[eeyang92]

Originally Posted by 5.M0NSTER

Yes sir, you know once you're hooked!

As for your questions:

1) Measure both at the rotor, and at the center of the caliper (Or hottest point of caliper you can find). The rotor temp is good to know so you can choose the right pad, the caliper temperature in turn tells you what temps the brake fluid is exposed to.

2) Stock fluid is not made to take much over 300F, stock pads will fade at ~800F

Castrol SRF, Motul 600 or similar take your fade resistance when dry (no moisture from environment absorbed into the fluid) to about 600F

Proper track pad will take 1300-2000F before fading.

3) Pads and fluids at the same time, ducts after. You'll be good for a while with high temp pads and fluid. Ducts come later once you're rally pushing into the brake zones, and on throttle enough to minimize cooling off time between brake applies.

BIG HINT: It's also important to maintain the right braking technique ONCE you have the high temp pads AND fluid. Brake LATE AND HARD! Don't ride the brakes till the apex when you already slowed down. This is the fastest way to overheat your brakes.

Does trail-braking count as riding the brakes? I find that the only way I can brake hard and late is if I am trail braking to aid my turn in - otherwise, I would miss the apex. Obviously by the time I'm nearing the apex I'm just brushing the brakes to control load transfer, so I figure there's minimal heat generated by the brakes from doing that.

[5.M0NSTER]

Originally Posted by eeyang92

Does trail-braking count as riding the brakes? I find that the only way I can brake hard and late is if I am trail braking to aid my turn in - otherwise, I would miss the apex. Obviously by the time I'm nearing the apex I'm just brushing the brakes to control load transfer, so I figure there's minimal heat generated by the brakes from doing that.

No, not at all. Load transfer to the front, so that the rear can rotate more after turn-in (trail braking), is not the same as riding the brake. The behavior I was referring to is starting to brake at the 5 marker at moderate pressure, bleeding off enough speed to enter the corner by the 2 mark, and still applying light brake pressure till turn in. I think it's a natural habit from street driving, which one has to train themselves out of at the track.

It takes me a good few laps before I start braking at the 3 or 2 marker and stay on throttle past the 5 and 4 markers. Self preservation instinct is still too strong early in the day.

Also if you're braking late chances are you need to brake past the turn in anyway, like you said. I aim to be just releasing the brakes past turn in, and be on throttle a little before the apex, then balance the oversteer with throttle.

[CrashFL]

The OEM brake pads tend to leave deposits on the rotors. I use Pagid RSL29 on track, and they work well. I'd recommend learning to swap the pads yourself-- it's pretty easy and there are plenty of videos to teach you how. Track pads squeal like a school bus on the street, so you're going to want to change them out for each event, if you drive often in between.

Welcome to the addiction.

[mr_lab_rat]

Originally Posted by CrashFL

The OEM brake pads tend to leave deposits on the rotors. I use Pagid RSL29 on track, and they work well. I'd recommend learning to swap the pads yourself-- it's pretty easy and there are plenty of videos to teach you how. Track pads squeal like a school bus on the street, so you're going to want to change them out for each event, if you drive often in between.

Welcome to the addiction.

I read about compatibility between OEM and track pads. Something about the same type of material. Which track pads would be most compatible with OEM?
I'm very comfortable with working on the car so I would have no problem swapping them.

[bentom2]

Originally Posted by mr_lab_rat

I read about compatibility between OEM and track pads. Something about the same type of material. Which track pads would be most compatible with OEM?
I'm very comfortable with working on the car so I would have no problem swapping them.

Pagid RSL 29 has played nicely with OEM pads for me personally, and I chose them because that seemed to be the consensus among others here.

[Twt]

Originally Posted by CrashFL

The OEM brake pads tend to leave deposits on the rotors. I use Pagid RSL29 on track, and they work well. I'd recommend learning to swap the pads yourself-- it's pretty easy and there are plenty of videos to teach you how. Track pads squeal like a school bus on the street, so you're going to want to change them out for each event, if you drive often in between.

Welcome to the addiction.

I use PFC08 pads for track...I leave them on for street but it’s not my DD. One bizarre discovery is that when I replaced my OEM front rotors with Stoptech slotted 2 piece, 90% of the street noise/squeal went away with the track pads still on.

[5.M0NSTER]

Originally Posted by Twt

I use PFC08 pads for track...I leave them on for street but it’s not my DD. One bizarre discovery is that when I replaced my OEM front rotors with Stoptech slotted 2 piece, 90% of the street noise/squeal went away with the track pads still on.

Interesting hint about the Stoptech rotors.

I'm a big fan of the PFC08 as well, and I swap it before my events, then return to OEM pad. No deposits at all, and no issues swapping back and forth. I love that the PFCs last forever, and offer high fade resistance. Also they have a good linear torque with only slight increase over temperature, making them easy to modulate. But FML, the noise!

[eeyang92]

Originally Posted by 5.M0NSTER

No, not at all. Load transfer to the front, so that the rear can rotate more after turn-in (trail braking), is not the same as riding the brake. The behavior I was referring to is starting to brake at the 5 marker at moderate pressure, bleeding off enough speed to enter the corner by the 2 mark, and still applying light brake pressure till turn in. I think it's a natural habit from street driving, which one has to train themselves out of at the track.

It takes me a good few laps before I start braking at the 3 or 2 marker and stay on throttle past the 5 and 4 markers. Self preservation instinct is still too strong early in the day.

Also if you're braking late chances are you need to brake past the turn in anyway, like you said. I aim to be just releasing the brakes past turn in, and be on throttle a little before the apex, then balance the oversteer with throttle.

Makes sense!

Haha, the self-preservation thing is real. I've given rides to friends who just started going to HDPEs and slamming the brakes really late after a long straight is an eye-opening experience for them

[eeyang92]

Originally Posted by mr_lab_rat

I read about compatibility between OEM and track pads. Something about the same type of material. Which track pads would be most compatible with OEM?
I'm very comfortable with working on the car so I would have no problem swapping them.

+1 for RS29. I've swapped between stock pads and track pads many, many times with no issues with vibration.

Honestly, I think it's more important to keep the same pads on the same rotors (and on the same side) and do proper bedding in procedures. The former is to ensure the wear patterns are similar for each pad and the latter will pretty much remove any traces of the previous pad.

Realistically, track pads (when cold) will scrub off the stock pad transfer layer, so when you get to the track, you take it easy the first session and bed in brakes there. When driving home, the track pads will be cold again and remove the transfer layer, then swap back to stock pads. Street pads bed in over time just by street driving so the whole procedure is actually pretty easy.

[JoeP]

Originally Posted by eeyang92

Makes sense!

Haha, the self-preservation thing is real. I've given rides to friends who just started going to HDPEs and slamming the brakes really late after a long straight is an eye-opening experience for them

Agreed! No one thinks a car can do what it actually can do. I always enjoyed taking out significant others for the first time back in my bachelor days. It was definitely the late brake that got them