Track Cars & Brake Issues

[OppositeLock]

Reading your thread was ultimately the reason I chose these pads. It’s good to hear you’re not experiencing this. Have you done anything else to your system? (Ducting, rotors etc?)

I'm running Girodiscs now, since I used up the OEM rotors. They definitely feel better, and the OEM rotors did have more vibrations, which I guess could be defined as chunkiness.

 

[Savanna7]

I'm running Girodiscs now, since I used up the OEM rotors. They definitely feel better, and the OEM rotors did have more vibrations, which I guess could be defined as chunkiness.

Sounds like that’s the next move then. Thank you for the input! I may try different pads next time as well. We’ll see.

 

[RoryBellows]

I just did my second track day on the stock pads/rotors and it did okay. Its smooth stopping all the way up until ABS kicks in.

 

[Savanna7]

I am not sure I understand the sensation of "chunky." I only have 2K mi. on the car and attended four track days thus far. I cannot say the brakes are great on the Emira, adequate probably is a better way of describing it for me. I have Jubu cooling vanes, Pagid RSL29 pads and RBF 660.

The way I would normally brake did not work for me on the Emira. Going from ~130 mph to 45, for example, I normally would apply the brakes pretty hard initially, then gradually taper off into the corner and transition to throttle. This worked well with my Porsches and BMWs, not so in the Emira. I had to gradually build up the brake pressure, then start to tapper off into the corner. This gradual build up is still quite rapid, but not as before, it takes about 0.5-0.7 secs. With the former method on the Emira I felt the pedal felt very hard, essentially like ICE mode. I believe the ABS was kicking in. With the later method, braking has been very consistent for more than 10 laps each session. I have confidence in braking, but necessarily the performance of my previous cars.

The downside is that the maximum negative g I could generate with the Emira is about 1.1-1.2, whereas with the others cars, I could consistently get -1.4-1.6. I do not know if any of this helps you, but I hope you find the issue and the fix.

Cheers.

I was just watching this video on a ZR1 comparison and what this professional driver is saying is nearly identical to your analysis. Maybe I'll give another track day a go before making any other adjustments. It could be ABS that I'm actually feeling although ours is hydraulic. I'm not sure.

24:50 is where it starts.

 

[Ft.S]

I was just watching this video on a ZR1 comparison and what this professional driver is saying is nearly identical to your analysis. Maybe I'll give another track day a go before making any other adjustments. It could be ABS that I'm actually feeling although ours is hydraulic. I'm not sure.

24:50 is where it starts.

He is certainly talking about what I experienced. The exception is that we can feel the change in brake pedal pressure, which is not communicated to the driver properly with electric systems, so we have one advantage. For our cars and for this specific issue, I think the real solution is to move to 265 section front tires on 9" wheels, and/or change in rotors as others suggested. Until then, I'll be gentle with the brakes

 

[BruceN]

Looking for those that track their Emiras frequently…..

I’m having brake issues that aren’t fully making sense to me. This happened with the factory pads for the initial shake down, and now the EBC RP-1s. I’ve read every brake thread I can find with no definitive answers.

Essentially, I can get about 3 great laps where everything feels exactly as expected. By the 4th lap, the brakes go from consistent and smooth to, inconsistent and “chunky” almost as if they are pulsing, or the pad material themselves are experiencing degradation and build up, but I would say it’s definitively not an ABS issue.

I’m currently running the factory Cup2s and have Motul 660 fluid already installed as well.

1. Due to it consistently happening within 4 laps, it sounds like a heat soak issue, but the brakes never get soft or mushy.

2. Based on number 1, it then leads me to think about heat based warping of the rotors and/or I read a thread about the parking brake getting involved once hot. If that were the case you would feel this all of the time after that initial saturation I think.

3. If it were air in the line, this would create a similar outcome to number 1 with a feeling of inconsistent pressure or mushy pedal, not the feeling I’m experiencing.

4. I could install brake ducting (and probably will), but I still think I would experience a brake “fade” issue rather than the feeling I’m getting when hot.

I was hoping I had a few loose lug nuts or caliper bolts that were allowing too much “flex” and a simple bolt check would solve the problem, but that has not proven to be the case.

Multiple people drove my car and felt the same sensation regardless of their pace. It was always on the 3rd or 4th lap. Each driver is very experienced in tracking and racing. One even owns a shop.

Is anyone else experiencing this? If so, how did you fix it? My next steps are trying a different set of pads and rotors while adding ducting, but that seems like an expensive game of chase, and I believe I read that at least two others had similar issues. Any help you can provide before I go down the economic rabbit hole would be helpful.

Thank you!

I've had similar issues. After a few hot laps, the brakes don't instill confidence! Sometimes the car pulls to the right under heavy braking that is disconcerting (this happened in my type R also). I adapt by changing the way I brake like you described - much more gradual (gentle) on, which isn't great to have to do. I've changed pads to no avail. Using EBC blue right now which work decently, but still have this problem. It happened with RP-1s also. I'm getting coilovers and changing to 18 inch wheels (not for this reason) and I'm hoping that might help. I see below some may have had success with upgraded rotors, but I hate to through money into some fixes that don't work out. I'm running TW200 Falkens, and had my brake fluid changed and it's still an issue.

 

[Tracked Emira]

I'm running Girodiscs now, since I used up the OEM rotors. They definitely feel better, and the OEM rotors did have more vibrations, which I guess could be defined as chunkiness.

What pads are you using in front and rear because Girodisc have their own pads they recommend now?

 

[bshads]

I hate to through money into some fixes that don't work out.

The rotors are the only obvious conclusion though, from all the issues described.
I tried fixing this with cooling ducts from Jubu... didn't work and they can't survive much abuse.
I then went to AP rotors and PFC pads and that fixed it. I'm very sure the issue is rotor related and not your pads.

I think the issue is that when the rotors get hot enough they start to warp. When they cool back down, they go back in shape. It might be isolated to a batch, multiple batches, or the design. This would be inherit to the casting, quenching, or design of where they put support tabs between the discs.

Anyway, my 2cents go towards a rotor swap. The issue should go away.

 

[OppositeLock]

What pads are you using in front and rear because Girodisc have their own pads they recommend now?

I'm using EBC-RP1. It's borderline too aggressive when hot. The Emira has BIG brakes for its power and weight, and I've found that the high friction compounds have too much initial bite, so I've actually been backing off on friction coefficient. You'll need to be gentle with the brake pedal with the RP1's. I do see uneven pad deposits on the rotor, but the braking seems ok.

 

[BruceN]

The rotors are the only obvious conclusion though, from all the issues described.
I tried fixing this with cooling ducts from Jubu... didn't work and they can't survive much abuse.
I then went to AP rotors and PFC pads and that fixed it. I'm very sure the issue is rotor related and not your pads.

I think the issue is that when the rotors get hot enough they start to warp. When they cool back down, they go back in shape. It might be isolated to a batch, multiple batches, or the design. This would be inherit to the casting, quenching, or design of where they put support tabs between the discs.

Anyway, my 2cents go towards a rotor swap. The issue should go away.

Thanks so much for your feedback - where did you buy your AP rotors from?

 

[BruceN]

I am currently using EBC Blue; tried RP-1s last year which felt awful - very bad vibrations
It sounds like the Girodisc are the way to go, though I'll probably run a few more days out of the stock rotors first. Also, getting 18 inch wheels so need to check the Girodisc are ok with that

 

[mr.suntorytime]

Girodisk will fit like stock but you won’t have the warble issues since these are fully floating. The oe are semi floating and can expand unevenly which causes the warble when hot. Girodisk or paragon if they have fronts. Can’t go wrong.

 

[RoryBellows]

EDIT: Keeping this here for history's sake but turns out I'm just an idiot. Caliper paint is too weak though. That part I stand by.

Obviously late to the party but the rotors can be pretty sus. I haven't actually had any noticeable issues from mine but if you look this picture of one of my front rotors near the caliper youll see where theres some extra grinding that happened on it. I think someone dropped the rotor at some point and they had to grind that bit off to correct it. Also of note the paint for the calipers is really thin and fragile.

 

[mr.suntorytime]

Obviously late to the party but the rotors can be pretty sus. I haven't actually had any noticeable issues from mine but if you look this picture of one of my front rotors near the caliper youll see where theres some extra grinding that happened on it. I think someone dropped the rotor at some point and they had to grind that bit off to correct it. Also of note the paint for the calipers is really thin and fragile. View attachment 78848

No, that’s how they are shaped. Everyone has flats on theirs.

 

[kitkat]

Obviously late to the party but the rotors can be pretty sus. I haven't actually had any noticeable issues from mine but if you look this picture of one of my front rotors near the caliper youll see where theres some extra grinding that happened on it. I think someone dropped the rotor at some point and they had to grind that bit off to correct it. Also of note the paint for the calipers is really thin and fragile. View attachment 78848

That's how rotors are balanced.

 

[RoryBellows]

That makes a lot of sense. Thanks for the knowledge drop. Ive edited the original post to account for my lacking.

 

[Savanna7]

Thanks for the feedback, everyone! Sounds like I need to get new rotors before Road Atlanta. That's not a track I'd be excited to use these factory ones on after the few events I've already had.

 

[Savanna7]

Also, rather than start a new thread, does anyone have a solution for a rear tow hook yet? Are there any Evora GTs out there rocking mini tow balls with track trailers? (I know that will make some people vomit inside their helmets.)

 

[RoryBellows]

If you go off just make sure to spin the nose towards the track.

 

[Tracked Emira]

Also, rather than start a new thread, does anyone have a solution for a rear tow hook yet? Are there any Evora GTs out there rocking mini tow balls with track trailers? (I know that will make some people vomit inside their helmets.)

Did you ever dyno your car to see what difference the new supercharger lid made?