Brake issues on the track

[Mike @ MRP]

Took the FRS to lime rock when I first got it and overheated the brakes 2 laps in. Wasn't too smart knowing the stock pads would do this anyway. So since then I've changed a bunch of things: steel braided lines, ate blue stuff fluid, centric blanks and carobtech p10 pads. Hoping this would do the job but mid way into my first session this passed weekend, same thing happen. Obviously not as bad but still started getting that soft pedal feel and bad brake fad.

I don't want to have to do a big brake kit since they're a ton of money. Any suggestions on what else to get around this. Maybe brake ducts could help a little?

Mod list: intake, front pipe, cat back, ecutek tuned on e85 by Visconti.

[OrbitalEllipses]

DOT unapproved brake fluid, yo.

[forwallblakmail]

Never ran at Lime Rock, but I tracked at PittRace this weekend which is decently hard on brakes. No fade in all 4 20 minutes sessions. I run Carbotech XP12's F/R and Motul RBF 600 fluid.

Mods are RCE Tarmac Springs, Koni yellows, front bar, 245 BFG rivals.

What tires are you running?

[CSG Mike]

Originally Posted by Mike @ MRP

Took the FRS to lime rock when I first got it and overheated the brakes 2 laps in. Wasn't too smart knowing the stock pads would do this anyway. So since then I've changed a bunch of things: steel braided lines, ate blue stuff fluid, centric blanks and carobtech p10 pads. Hoping this would do the job but mid way into my first session this passed weekend, same thing happen. Obviously not as bad but still started getting that soft pedal feel and bad brake fad.

I don't want to have to do a big brake kit since they're a ton of money. Any suggestions on what else to get around this. Maybe brake ducts could help a little?

Mod list: intake, front pipe, cat back, ecutek tuned on e85 by Visconti.

Did the pedal get mushy, or the car just stop braking?

What kind of tires are you on? (Make, model, and size) Are you running XP10 front/rear?

XP10 is great for intermediate level guys, but if you're quick, XP12 is the way to go (assuming you want to stick to Carbotech). If you're in a hurry, I believe we have it in stock.


It's very possible that they were bedding the 1st session; did the brakes improve later? ATE generally is not suited for quicker drivers. I'd recommend trying Motul RBF600. If that doesn't work, step up to Project Mu. If that doesn't work, then Torque RT700.

This isn't a FR-S/BRZ, but this picture is from the past weekend, with Project Mu 999, and Torque RT700. One of the rotors cracked during cooldown, but the brake fluid didn't get mushy, and the pads never faded.

[7thgear]

did you bed the pads/rotors in?

[subaruferrucci]

almost sounds like you are not applying your brakes aggressively enough. when you are on the track you should be braking much harder. When you drag the brake like you are rolling up to a stop sign looking for the smooth stop you will boil your fluid really fast

[ATL BRZ]

Proper bleeding of the system as well as proper bedding in of the pads is important, but the stock style rotors need better cooling.

Check out my build thread for my solution. I installed the Touge Factory brake cooling kit which features ducts, hoses, and a proper backing plate that helped tremendously at the track. I can drive 9 or 10/10ths now on track and the brakes are consistent into every corner.

Also get a master cylinder brace, that helps a lot with solidifying the pedal feel in threshold braking situations.

[smbstyle]

First off, let me get this one out of the way, I hate Carbotechs, and always had issues with them. Are the pads bedded properly? Carbotech has specific directions on properly bedding them.

I'll notice a "soft" pedal after a cool down lap going into a hard braking turn, as the pads have cooled down significantly, but usually 3 to 4 seconds in the bite gets progressively better.

Soft pedal sounds like a fluid issue. There could be air in the lines or you could be boiling the fluid, but I don't think Lime Rock is the kinda track that would boil fluid. I ran ATE at Sebring on all my cars without issue (CTS-V, Miata).

If the pedal feels still kinda firm, but theres no bite, pads could be glazed. Take them out, rub them against the concrete, and re-bed.

One thing that not a lot of people think of is pad knock-back, which I had an issue with on my Miata. It is when the lateral movements through the corners will push the pads out from the rotor surface, so when you go to the brakes, pedal goes to the floor for the initial pump, and is definitely a butt-clencher.

I do a light brake tap in the straights before the brake zone by habit after my Miata race car, so I wouldn't know if this car had that issue or not.

[Mike @ MRP]

Originally Posted by forwallblakmail

Never ran at Lime Rock, but I tracked at PittRace this weekend which is decently hard on brakes. No fade in all 4 20 minutes sessions. I run Carbotech XP12's F/R and Motul RBF 600 fluid.

Mods are RCE Tarmac Springs, Koni yellows, front bar, 245 BFG rivals.

What tires are you running?

Sorry, forgot to mention wheel and tire combo. 17x8 kosei and Rivals 225 wide.

[Mike @ MRP]

Originally Posted by CSG Mike

Did the pedal get mushy, or the car just stop braking?

What kind of tires are you on? (Make, model, and size) Are you running XP10 front/rear?

XP10 is great for intermediate level guys, but if you're quick, XP12 is the way to go (assuming you want to stick to Carbotech). If you're in a hurry, I believe we have it in stock.


It's very possible that they were bedding the 1st session; did the brakes improve later? ATE generally is not suited for quicker drivers. I'd recommend trying Motul RBF600. If that doesn't work, step up to Project Mu. If that doesn't work, then Torque RT700.

This isn't a FR-S/BRZ, but this picture is from the past weekend, with Project Mu 999, and Torque RT700. One of the rotors cracked during cooldown, but the brake fluid didn't get mushy, and the pads never faded.

I'm running the xp10 in the front and sad to say stock pads in the rear (yes I know dumb lol). I do consider myself to be quick on the track. Currently hold lap record at lime rock with my spec miata. I had the FRS clocked at 1:03.2 which I was very impressed with.

Going to order rear pads this week, do y recommend going with xp10 or xp8 for the rear. I just got the xp10 for the fronts so going to just burn them out and go with xp12s next time around. Only issue is the car is daily driven so I didn't want to go with such an aggressive pad.

As for brake fluid, I guess ate isn't cutting it for me. Going to switch over the motul this week. Running it at njmp next week which requires more use of brakes.

[CSG Mike]

Originally Posted by Mike @ MRP

I'm running the xp10 in the front and sad to say stock pads in the rear (yes I know dumb lol). I do consider myself to be quick on the track. Currently hold lap record at lime rock with my spec miata. I had the FRS clocked at 1:03.2 which I was very impressed with.

Going to order rear pads this week, do y recommend going with xp10 or xp8 for the rear. I just got the xp10 for the fronts so going to just burn them out and go with xp12s next time around. Only issue is the car is daily driven so I didn't want to go with such an aggressive pad.

As for brake fluid, I guess ate isn't cutting it for me. Going to switch over the motul this week. Running it at njmp next week which requires more use of brakes.

We recommend square pads; that's where we had the best results with braking distances.

Yeah, you're quick. You're fading the XP10 fronts; I did some informal testing with just XP12 front/stock rear, and I was fading them after just a few hot laps, so a drive of your caliber has to be feeling the pain.

I suppose I should mention, brakes on this car wear much faster than on a Miata...

[rice_classic]

Do you know how to properly bed-in (or burnish) Carbotech's?

You have to brake from 60mph to 10mph 3 times on a summer day with the sun at the 4 O'clock position all while crossing all the fingers on both hands and praying to Vishnu with a memorized chant that will be provided by Carbotech.

What's wrong? Didn't cross all of your fingers? Well, UNEVEN TRANSFER LAYER FOR YOU!

[rice_classic]

Originally Posted by subaruferrucci

almost sounds like you are not applying your brakes aggressively enough. when you are on the track you should be braking much harder. When you drag the brake like you are rolling up to a stop sign looking for the smooth stop you will boil your fluid really fast

This is no joke.

When I was learning how to race, I was destroying my brakes. I was on them too early, too little and for too long and entering the corner too slow. Just a change in driving fixed it all.

Brake late, brake hard, carry more speed into corner. (But be safe!)

[smbstyle]

Originally Posted by rice_classic

Do you know how to properly bed-in (or burnish) Carbotech's?

You have to brake from 60mph to 10mph 3 times on a summer day with the sun at the 4 O'clock position all while crossing all the fingers on both hands and praying to Vishnu with a memorized chant that will be provided by Carbotech.

What's wrong? Didn't cross all of your fingers? Well, UNEVEN TRANSFER LAYER FOR YOU!

aint that the truth.

I think I went from 62mph to 11mph 3 times at 4:15 pm. probably I had all kinds of issues with the Carbotechs.