Mach5gsxr

I destroyed the stock brakes at Watkins Glen, then I destroyed my aftermarket brakes. The aftermarket brakes started to get hot spots on the street at very high speeds with intersecting highways which had no other cars, I was basically looking forward to seeing what they can handle. Once I got it to Lime Rock they were destroyed within 20 minutes. Yes I bedded the brakes and used them properly, apparently “500rwhp” (COBB claims) and hard driving is too much for the BS size brakes that this car comes with.



This is the setup (COBB tune as well):

•Sport Cup 2 Tires.

•Front and Rear Cryo treated slotted Girodisc.

•Pagid RS29 Yellow brake pads.

•Pagid RSL29 yellow brake pads rear.

•Motul RBF660 brake fluid.

•Steel braided brake line set, Spiegler.



Any suggestions on the most value for a big brake carbon setup? I do not want to take a chance with steel and yes I’m aware that most track with steel.

I have a C8 Z06 on the way and plan to keep both of these cars for life, spending 10k on the GTS is worth it to me, it is a manual and I want to keep it.


Help is very much appreciated.

JRitt@essex

Sorry to hear about your brakes. All of the newer turbocharged 911s have tremendous potential for speed with the turbos, as you've just found out! You're simply pouring too much heat into the stock-sized components. You need a proper brake setup designed specifically for track abuse. Carbon ceramic is NOT the way you want to go, unless you want to be poor along with being frustrated. Carbon ceramic brakes have a laundry list of issues when used extensively on track. We wrote an article on the topic which you can read on the Essex blog: Are Carbon Ceramic Discs Better than Iron
Carbon ceramic discs are NOT the same thing that you see on IMSA racecars and Formula 1. Those brakes are carbon-carbon, which is a completely different material (which the article above explains).
Please do yourself a favor and do not go down that path. We've helped thousands of people who have switched away from carbon ceramic, and I hate seeing people pour their money down the drain following that path. You are going to have people here on the forum tell you that's the path to follow, but many of these folks are speaking only from their personal experience. We have people tell us all the time that their carbon ceramic brakes work fantastic under the most grueling conditions, and then we watch a video of them puttering around the track at 6/10ths and barely using the brakes. Our systems have been proven at all levels of motorsport. If you click some of the links I post below, you'll see actual results and evidence based on decades of experience, not conjecture.

Brakes are a chain. If the foundational link in the chain isn't strong enough, the whole thing breaks down. If your discs don't flow enough air or don't have enough mass to hold the heat that is being generated, they run too hot. When your discs run too hot, your pads are overheated (even racing pads with a high max operating temperature like Pagid endurance pads have their limits). When the pads are overheated, you get pad fade (you step on the brake pedal, it remains firm but the car doesn't slow as expected). The overheated pads also send that heat into the caliper pistons, which in turn heats the caliper body, and the brake fluid inside. When your brake fluid boils, you get air bubbles in your lines. Since the brake hydraulic system is closed, there's nowhere for those bubbles to go. You step on the brakes and those bubbles are squished in the lines, giving you a soft pedal...we call that fluid fade.

When you say destroyed, what exactly happened? I see that you noted pad smearing, which is a sign that your pads exceeded their max operating temp. What else happened?

• You had pad fade?
• You boiled your fluid?
• Your pads fell apart?
• Your discs cracked?
• You saw air bubbles in your brake lines?

While there's nothing 'wrong' with Girodiscs you were using per se, sometimes you need more thermal mass in the discs and even greater resilience and efficiency in your other brake components. As horsepower goes up, your terminal velocity at the end of the straight goes up. That means more energy from the spinning discs is being converted into heat in every brake event. That amount of energy rises exponentially with speed. When you tune your car, increase it's ability to get through turns faster, etc., you are also increasing the demands on your brakes.

I would put forth our AP Racing Radi-CAL Competition Brake Kit for your consideration. It is as close as one can get to AP Racing Radi-CAL brake system the Porsche 911 RSR uses to win Le Mans each year. We have loads of modified Porsches, Corvettes, Camaro ZL1, etc. successfully running our systems with 500HP to 1,000HP. Many of those cars are front-engine layout, which is typically much harder on the front brakes than a 911. Take a quick peek at our blog in the link below to see the cars we're supporting. Our customers are winning club races, national championships in NASA, Trans AM, IMSA, USTCC, NASCAR Cup, IndyCar, etc. You can see the myriad of owners we've helped on our main blog page:
https://www.essexparts.com/news-blog

Here are our front and rear kit for the 991.2 GTS:
Front= https://www.essexparts.com/ap-racing...1372mm-porsche
Rear= https://www.essexparts.com/ap-racing...orsche-997-991

Here is a link that specifically shows reviews of our brake systems from other Porsche owners like yourself: https://www.essexparts.com/news-blog...-kit-is-a-must

One that specifically comes to my mind is a 991.2 Carrera T with 700 wheel horsepower who has been tearing up tracks with our 372/365mm brake kit: https://www.essexparts.com/news-blog...tion-brake-kit

What does a complete aftermarket brake kit bring to the table?

• Discs that have more thermal mass than stock. Our AP Racing Radi-CAL system uses 372x34mm discs up front. Not only do they have more mass than the stock units, they are far more efficient (and have also proven more efficient than other aftermarket discs). They flow more air and run at lower temperatures than what you've already tried.
• Calipers designed to withstand any and all track temps they'll ever see- No need to remove calipers to swap pads, ventilated stainless steel pistons to resist heat soak, anti-knockback springs behind the pistons to keep the pedal firm, caliper body that allows air to flow through and around it, heat-resistant finish that won't change colors and look terrible, high temperature seals that won't get brittle and leak at track temps like the stock ones do, accommodate a huge range of road and racing brake pad compounds from all major manufacturers
• Reduce unsprung mass. Despite being larger than stock, our calipers and discs are designed to be as light as possible and typically weigh less than stock.
• Tight packaging that allows for the smallest, lightest track wheels possible
• Far slower rate of consumable consumption (pads, discs, and fluids)- Many of our customers find that our brake kit pays for itself over the course of a few years tracking their car. The more you track, the faster it pays for itself.
• Fantastic resale value/preservation of OEM brake bits- Our kits typically trade hands on the used market for 65-70% of their original price. You use them for a few years, and then sell them to recoup a large chunk of your initial investment. Meanwhile your OEM brakes are preserved on your garage shelf and your car doesn't look thrashed when it's time to sell it and move on.

Watkins Glen is one of the hardest braking tracks in the USA (alongside Road America, Sebring, COTA, etc.). Long straights followed by heavy brake zones, followed by another long straight is a recipe for brake destruction. That is because the brakes see wild temperature swings. Those temp swings are a recipe for cracked discs and general brake destruction.

We (Essex Parts Services) are the exclusive North American importer and distributor for AP Racing and have been in business since the early 1980s. We currently support both the aftermarket and professional racing, including supplying the entire NASCAR Cup field with AP Racing Radi-CAL brakes. We are not hobbyists or dabblers. We have a staff of employees dedicated almost purely to brakes, a warehouse full of spare parts at our Charlotte, NC headquarters, a brake dyno in our facility, a team of engineers, and you will always get a live human on the phone when you call us for help.

We've had hundreds of 991 GT3/RS, GT2RS, and 992 GT3 owners dump their stock brakes (which are much, much larger than the OEM brakes on the GTS), and switch to our system. Again, you can see many of their stories in the links above. Also, below is a video that we put together that walks through each of the design features and explains why we are superior to stock.


FYI...we also have complete brake solutions for Corvettes, including the C8. We are the number one choice in brakes for the Corvette market. The C5R, C6R, and C7R all won Le Mans on AP Racing brakes many times over a 20 year period. I personally have helped thousands of Corvette owners with their brakes over my twenty years in the brake business. I have also owned and tracked a C5Z06 and C6 with a 403 stroker engine for years. Below are a couple of videos from our development testing of the C8 at Road Atlanta.

Frank 993 C4S

What do you mean by "destroyed"? Assuming you are running street tires, I would be surprised if you could not have this figured out without resorting to an aftermarket solution.

John Mclane

I had similar problems and went a similar way on my prior (991.2). The problem is that's a heavy car with lots more power than designed for.
Same issue on the 992 (C4S cab, a bit of a porker), even heavier. I got the BBK from Jeff. On slower tracks it holds its ground. On Road America (where I am right now), it survives, but the pads go out quickly.
Tuning a car has that issue. Unfortunately what you don't want to hear (neither do I) is that you need to pace yourself.

Mach5gsxr

Sorry guys look up my other thread posted, it’s titled the same. You will see all the pictures and what I decided on.


thanks.

T&T Racing

Disclaimer: I am not an employee of Essex Parts nor do I personally know anyone associated with Essex. My experience is building race cars in the 1970's and driving and maintaining a Porsche 944.

The primer brake system in the late 1960's was the F1 Girling Brake System with a vacuum hydraulic booster to increase the front brake pressure 1.5 x the rear brake pressure for gross brake bias and then fine tuned with the brake bias bar between the front and rear brake MC 's. Why the vacuum hydraulic brake booster? Front and rear Giirling calipers had 4 identical brake pistons. Our team still used this setup because they were collected free from the Penske race shop. We had a limited budget but was competitive in TransAm and IMSA over 2L Race cars.

My qualitative evaluation of the AP Racing Radi-CAL Competition Brake K system is several generation ahead of the Girling Brake System. Comparing the AP brake system with the Brembo brake system, the AP system is one generation ahead of Brembo.

Brembo is using marketing strategy and catch up modifications to get closer to AP. AP has by far superior the best fully integrated design for caliper rigidity, caliper cooling, and minimizing brake pad backing heat transfer to the brake piston or puck.

AP has a full service rebuild department with reasonable refurbish prices.

As a side bar: Mark Donahue put 2 brake calipers on the front rotors of his TransAm Camaro. He discovered the setup forced him to brake earlier, insufficient rotor mass to absorb the heat input and insufficient time to release the heat before the next brake point.

lnirenberg

I put a full AP racing setup on my 991 GT3 and they are the best brakes I have ever had the pleasure of experiencing including the OEM carbons on a turboS, no fade no problems. In the interest of constructive criticism, you may want to consider your braking “style” because of all the tracks in the northeast, Lime Rock is the last place I’d expect someone to destroy their brakes on any full day let alone a session.