JRitt@essex

Hello Gents,

Over the past couple years we've built a very loyal following among GT3 owners for the brake products that we supply: AP Racing J Hook discs, Ferodo DS1.11 pads, Spiegler Stainless Steel Brake Lines, and AP Racing Radi-CAL brake fluid. I'd like to first say thank you, as we really appreciate all of your support! We've helped our customers stay on track longer, made working on their car easier, and helped them lower their running costs by a considerable amount. That said, our customers still consistently call us asking for better brake solutions. They're tired of removing their calipers to change pads, dealing with broken ceramic piston caps, and spending a lot of money on OEM replacement parts, only to have the same problems occur again.

I'm very excited to announce that we've finally developed the ultimate brake solution for the 991 GT3/RS. It addresses all of the complaints our customers have expressed, and several other issues that they haven't even yet considered. Our new system is based on AP Racing's Radi-CAL caliper technology, as employed on the latest 911 RSR. The Radi-CAL is currently the dominant technology in professional motorsports around the world, and there really isn't anything similar available on the market at any price. We're extremely excited to bring this cutting-edge technology to GT3 owners, and we believe it will greatly enhance their ability to extract the most performance from these awesome cars.

Objectives:

Some of the goals we outlined at the outset of this project were:

• Maintain the use of the parking brake on the rear kit

We are pleased to report that we are on track to accomplish every one of those goals!

Below are some pics of our GT3 plans laid out for discussion during a recent meeting. You can see the various kit components front and rear.







Is This for Real?

Yes, yes it is.

With these systems our customers have amassed a lengthy list of NASA and SCCA race and championship wins, time attack victories, rally and hill climb wins, lap records, etc. I'd highly encourage you to take a peek at our blog, which contains a slew of product reviews and race results from our customers. Below are some links to discussions about our Essex Designed Competition Brake Kits on other forums. Not only do these posts show the success that our customers have had with our products, they show the lengths to which we go to support our customers.

Corvette C7 Z06
E92 M3
BRZ / FR-S
Lancer Evo

Please also watch the videos below to learn about our design philosophy, the components we use, and why they are superior to other available options.







When Can I Get One?
We are shooting for an early 2018 release. Once we finalize every detail and get them into production they will be available for pre-order.

How Much Will it Cost?
Slightly more than the OEM iron brake system, and far, far less than the OEM PCCB system. Pricing will be in line with our kits for other platforms. While we don't plan to impose an artificial "Porsche Tax", this system will be a bit more expensive than some of our other kits because we will be using low volume, custom disc solutions on both the front and rear (as opposed to the standard disc sizes that we buy in very large quantities).

I'll post details on the various kit components in the coming days. As always, you can feel free to PM me, email me, or call us at 704-824- six zero three zero. Thanks again for your continued support!

thebishman

Everyone that I know who has these brakes on their C7 Z06 have been incredibly impressed by every single aspect of this OEM replacement. Worth every $.

Bish

Sean in Texas

Jeff,

For those of us who have already invested in the rotors, will there be any discount for the rest of the package? Or will we have to buy them again?

JRitt@essex

Thank you Bish! We definitely can't have Z06s out-braking GT3s any longer!

That's a completely fair question Sean. I need to think on that one a bit. Since many of our sales are through wholesalers, it complicates things considerably. I'll see if I can figure something out though. We really do appreciate our loyal customers, and thank you for your support with our discs!

Mvez

Hell yes. I have the Radi-Cal CP9660 caliper kit on my M3, and it's an awesome brake setup, and I only have the fronts, LOL. The best I have ever used. Glad to see you guys put the time and effort into this, you will be rewarded, I promise. This will also make it much easier for people to change from street to track pads as well.

A couple of questions:

1. I know they come in the anodized dark grey, but be prepared for the onslaught of questions about "can I have my calipers painted". If multi-colors will be an offering, which is honestly a good idea for Porsche-world, I would probably let people know up front either way to avoid a million questions.

2. Can we choose knock-back spring rates? If not, what will be the softest spring used? The 911 seems to not suffer from knockback as much, compared to say the M3 or Vette, where the weight and deflection from load up front are more. Perhaps a softer spring could be used?

I'm sure I'll get a set for my inbound .2GT3, late January delivery. Look forward to details

orthojoe

Sweet!

AP rotors are the ONLY way to go if you track a lot. The front rotors last 30+ days and my rear rotors still look new over 70 track days later.

The ceramic pucks are an issue, and the pad changes are a PITA when it comes to the OEM calipers. These calipers would solve that issue.

Jeff, what are the brake pad options and how much do they cost compared to the OEM shape ferodo ds1.11?

nxfedlt1

would be even better if I could fit 18" wheels over these!!!

JRitt@essex

Hey Mvez. I remember your screen name from M3post. I think I read a suspension review from you earlier this year, and I think we emailed back-and-forth at some point as well. Thanks for your support on the M3 brakes, and we're glad you're enjoying them!

We follow a strict Henry Ford policy...You can have them in any color, as long as it's anodized gray. Paint doesn't hold up nearly as well as anodizing on the track, and we have no plans to offer any other colors. I like to think of them as gorgeously-utilitarian. They aren't flashy, but they definitely look the business.

Understood on the deflection, and thank you for the data point. We will use a very light 4 lb. anti-knockback spring on both the front and rear calipers, and there won't be any option to switch those out. These would be the same as what is in your CP9660's. We don't anticipate any issues with brake drag, etc. Across all of the platforms we service, that topic almost never comes up, and the benefits of having the springs tend to far outweigh any concerns about them. Eliminating the dropping pedal and ensuing pucker-factor 11 after a series of S curves into a hard brake zone is something our customers certainly relish!

Excellent! Congrats on the new ride. What color did you order? Our goal is to start delivering our kits early in 2018 so people can pull their minty OEM brakes off their new .2GT3's and stash them on the garage shelf for preservation.


Very nice Joe! Thank you for choosing our products, and I'm happy to hear they're performing as expected. That's a lot of hard miles on those discs, and we certainly predict more of the same out of the discs in our complete kit.

Pad options are incredibly plentiful. The pad shapes we're using were designed by AP Racing years ago, and are produced by just about all major pad manufacturers around the world. Ferodo makes both shapes, and the cost is very similar for both. The good news is that the shapes for our AP Racing calipers aren't outlandishly expensive. In this case they're actually less expensive than the OEM Porsche shapes. You'll likely see that across most pad manufacturers. Here's a cost comparison on the Ferodos:

OEM GT3 shapes:
Front=FCP4664W=$495.90
Rear=FCP4665W=$487.49
Front and rear car set= $983.39

AP Racing CP9661 (front)
FRP3144W=$462.34
AP Racing CP9449 (rear)
FRP3018W=$362.51
Front and rear car set= $824.85

nxfedlt1,
We would have loved to squeeze our setup inside 18's, but it's unfortunately not possible on this application because of how the OEM calipers are mounted. With a fixed opposed caliper, there are two primary mounting methods, radial and axial/lug. The OEM GT3 caliper is a radial mount. Below is an example of a radial mount. It has small, flat pads/bosses on the underside of the caliper. Those pads rest on the spindle, and bolts go through the top side of the caliper into the spindle.




A radial mount caliper bolts onto a spindle that looks like the one below. The caliper can't really be pushed in any closer to the hub:




The other method of mounting an opposed piston caliper is axial mount. Two little ears/lugs hang down from the inner half of the caliper, and those ears are bolted to the spindle from the side. An example of that type of mounting is below:





An axial mount caliper bolts onto little ears that protrude from the spindle. You can see them on this corvette spindle:





The OEM GT3 calipers are radial mount, and they ride on a disc with a diameter of 380mm. That poses a bit of a dilemma. There's no way to pull the caliper in closer to the hub to fit on a smaller diameter disc. With an Axial mount setup, that is sometimes possible depending on how you orient the bracket and the caliper. You can get crafty and work around the little ears that stick off of the spindle. In such cases, the caliper doesn't necessarily have to be located as far away from the hub as the OEM caliper.

If the mounting holes on the AP Racing calipers were spaced exactly the same distance apart as the OEM calipers, you could simply bolt the AP Racing calipers onto the spindles just like the OEM calipers. Unfortunately, the spacing of the mounting holes is different. As such, an adapter bracket must be fabricated, and there needs to be space to sandwhich that adapter bracket between the spindle and the caliper. That means the caliper must be pushed out towards the wheel barrel to accommodate the bracket...hence a disc that is a larger diameter than stock must be used. Once you go larger than the 380mm of the OEM disc, there's no real hope of squeezing them inside 18's. In most cases, it's very tough to even squeeze a 380mm disc inside an 18" wheel. In our experience, a 372mm diameter is about as large as you can go to comfortably clear a range of 18" wheels.

Hopefully the above makes sense!

JRitt@essex

Radi-CAL Calipers

Radi-CAL is the term used to describe AP's design language for their latest generation of calipers...as in, "Radical departure from conventional design". I wrote a story for our blog and we produced a video that looks at the technology of these calipers. If you read the blog post in the link below, there are also some magazine clippings discussing the tech from several publications such as Race Tech magazine.

The AP Racing Radi-CAL Story

To boil it down to its essence, the Radi-CAL technology allowed AP Racing to design the lightest, stiffest, coolest-running calipers ever conceived. Rather than building a caliper that was a stiff box when sitting on a table, AP started by evaluating the forces that actually act on a caliper when it is in use on the track, and worked backwards into a design that combats those forces. Every ounce of the caliper that isn't contributing towards that goal is stripped away, leaving only a skeleton. Essentially, the Radi-CAL is an exoskeleton.

When Essex and AP introduced the Radi-CAL into NASCAR in 2007, they immediately took over the field, and have been winning championships ever since (read the story in the link above for the full details). Similar situations occurred in various other professional motorsports series around the world...F1, DTM, IMSA, Aussie V8 Supercar, Super GT in Japan, etc. The Radi-CAL is widely regarded as the most advanced racing caliper technology available. It has been a 'home run' product for AP (and Essex), and frankly made conventionally designed calipers more or less obsolete in higher level motorsports. Other manufacturers rushed in to imitate the design, and there have been several patent infringement cases, etc.

For the first several years of their existence, Radi-CALs were only produced as one-piece billet pieces, which required an enormous amount of machine time. They had to be whittled away from numerous angles/axes, and the cost was extraordinarily high. A few years back, AP Racing finally developed a forging process that would allow a two-piece Radi-CAL to be created. The Pro5000R Radi-CALs in our GT3 are that product. They offer the stiffness, weight savings, and cooling benefits of the early monobloc billet designs, with the convenience and practicality of a removable bridge for pad changes. Over the past several years we've been expanding our line of Essex Designed AP Racing Radi-CAL Competition Brake Kits for popular platforms used in club racing, time trials, HPDE, AutoX, etc. As you can already see by some of the comments in this thread, we are a popular option in other markets such as the Corvette, M3/M2, BRZ, STI, Evo, etc. Recently we've been expanding our Porsche fitments. We released our front and rear Radi-CAL kit for the 987 Cayman/Boxster a couple months back, and we will start shipping our 981 kits in 5-6 weeks. We're currently working on getting more cars in for measurement, including various iterations of the 911, the 718, GT4, etc.

Our front GT3 kit will be based around the AP Racing CP9661 Radi-CAL. The CP9661 caliper is a forged two-piece unit that weighs a scant 6.2 lbs., whereas the OEM front caliper weighs in at 9.0 lbs. As noted above, the Radi-CAL is by far the stiffest design available, enhancing brake pedal feel and modulation. These calipers are equipped with ventilated, domed-back stainless steel pistons with anti-knockback springs. These pistons do a tremendous job of keeping heat out of the brake fluid, and our customers typically find that they can withstand years of heavy track abuse. The calipers also feature high-temperature internal seals, which have an incredibly long service life. Here's an example of a Corvette customer who ran a set of our calipers on his racecar for three years without a rebuild!

Mech33

How do the 991 Cup Car and GT4 CS end up fitting 18” wheels? Do they run different spindles, or just different calipers?

JRitt@essex

I'm fairly certain they are running a different spindle. I honestly don't know though as we've never had hands on them. Again though, some 18" wheels will indeed clear 380mm discs. It's more unusual than the norm though.

Hams955

I am running a Radical kit front and AP racing kit on the rear of my Z06 race car. I have to say - the system is amazing. I couldn't be happier with the brakes on that car. In fact, I upgraded from Brembo race setup to the Radical; and quite the upgrade.








Jeff - I have a set of spare 997.2 Cup uprights if you'd like to take a look at them. Of course, your interest level may be more in the 991 cup at this point, but I'd be interested in a set for my cup. I run my car in NASA not PCA. I am not restricted on brakes.

- Chris.

tstafford

Looks awesome. Can’t wait to hear pricing.

JRitt@essex

Awesome Chris! Thanks for the kind words, and I'm glad the brakes have been working so well for you. If you could do me a huge favor and post your wheel data in our official wheel fitment thread on the Corvette forum, it would be much appreciated! We're trying to expand our wheel fitment database.

We may just have to take you up on that! Thank you very much for the kind offer. Myself and a good portion of our team will be attending the SEMA show all next week, and I'm also in the process of lining up a few more P cars for data collection the week we get back (GT4,718 S, 991 GTS). I'll talk with engineering and see when we can fit this in. I think more data is always a good thing, particularly with Porsche. They tend to have very small differences across the lineup, and customers seem to want to swap every part from one variant onto every other variant. Having more data points will help us for sure. Thanks again, and I'll get in touch with you in a couple of weeks.

sasportas

Jeff,

Those new calipers look great.

Will there be any problem clearing the 19" Forgeline wheels that most of us run on the 991 GT3?

Also, the stock front brake set up has a very long hard brake line. Are there any issues with using the flexible line in terms of clearing vital components such as the springs?

Will the brake fluid volume be affected with these calipers? Will it mess up any of the ABS calibration?

Thx