JRitt@essex

Hello Gents,
We (Essex Parts Services) are the exclusive importer and distributor for AP Racing competition brakes in North America. We are now offering front and rear AP Racing Heavy Duty J Hook discs for the 997 GT3 platform. Our goal was to produce the most durable, overbuilt disc on the market, and I believe we've done just that.

As many of you know, AP Racing discs are widely considered the go-to choice in professional racing. Over the years they've won countless races and championships in ALMS, NASCAR, DTM, Rolex, etc. AP Racing has also won over 750 Formula 1 races with their brake and clutch products.

We are using the same designs, materials, and attachment mechanism for these discs that we use in pro racing. As such, these particular discs are far more stout, and will offer superior performance and longevity vs. other available options! They feature 72 directional vanes (most competitors use 48), and highly crack-resistant metallurgy.

These are the disc options:
380x34mm Front: Retail $1798 per pair, iron replacement rings $399 each
350x28mm Rear: Retail $1498 per pair, iron replacement rings $339 each

I wrote this post in the 991 GT3 section which contains many of the details about the product and our company. Everything in that post essentially applies to our discs for the 997 GT3.

We're also working on the web page for the rear discs, and it will be done soon.

Please shoot me a PM, email me, or call us at seven-zero-four-824-6030 if you're interested in a set of these discs.

Here are some pics to give you an idea of what they look like:

orthojoe

FWIW, Jeff asked me to test these rotors on my 991GT3. I've been very happy with them. They weigh the same as OEM, and the ring replacement costs are much lower than entire OEM rotors.

541 track miles and 5 track days (2 at Thunderhill, 2 at Laguna, and 1 at Sonoma) and they still look good and have performed flawlessly.

zweebach

I've been running AP discs on my car for several years and have been very happy. The pricing listed here is great!

Jamie_GT3

Will these fit Brembo hats?

Clark-ApexPerformance

For those of you considering AP discs....we are a stocking dealer and have chosen to partner with Essex on AP rotors/hats and Ferodo pads.
We believe both AP and Ferodo to be superior products.
Call me with any questions.

Clark-ApexPerformance

Jamie most all the brake people make their rotors and hats sightly different so you
can't interchange parts. Their is a possibility the AP and Brembos will be interchangeable as Brembo owns AP.
Jeff Ritter from Essex will respond to you on this Monday.

JRitt@essex

I've had lots of questions about swapping discs and hats within the AP Racing brand, across other brands, etc. In most cases swapping iron discs onto hats for which they were not intended will not work. Here's why:

PCD

The primary issue that you'll constantly run into with trying to make one disc fit with the hats from another disc is a difference in PCD (Pitch Circle Diameter). The PCD of a disc is the distance between the center of the mounting holes on the opposite sides of a disc. It is typically shown in mm. Here's a pic as an example:



If the distance between the center of those holes on the two discs under consideration is not identical, then a given hat will not be centered on those two discs in the same manner. On a floating disc, the whole point is to allow the disc to have freedom for expansion when it is heated. Here are a couple of pics from our website showing how this works with the attachment mechanism we use:









If the PCD of two discs are different, the bobbin will not be perfectly centered in the oblong hole on the disc flange. That means it won't slide smoothly, can bind up, cause stress risers, cracking, etc. Basically, your floating disc will no longer be floating!

Floating Mechanism

Another issue you'll run into is that the floating mechanism used on particular discs can be quite different. That is within a given manufacturer, and across manufacturers. That is why you can't slap Brembo iron on an AP Racing hat and vice versa. Some used bolted/fixed hats, where there is no float. Some use a float-in-hat (the bobbin slides in the hat rather than the oblong channel in the iron), rather than float-in-disc. Some mechanisms have twice the number of attachment holes that we have. Some have fewer. There are tons of variations, and they all have different intended purposes, strengths, and weaknesses.

The mounting system we use has been proven countless times in pro racing, is simple, reliable, and inexpensive. It doesn't have a million pieces to keep track of, is quick and easy to assemble, allows a great deal of float/disc expansion, doesn't rattle and make noise...it's a great setup.

If you want to look at the drawings of our specific discs to check PCD and other dimensions, you can do so at these links:

Essex/AP Racing 380x34mm, CP6572-102/3GA

Essex/AP Racing 350x28mm, CP6472-102/3GA

Hopefully that clarifies the issue of swapping iron disc rings and hats. Thanks.

JRitt@essex

Hello Gents,
Just an FYI...The rear 997 GT3 AP Racing discs are now in stock and ready to ship. Thanks!

Clark-ApexPerformance

Tired replacing those cross drilled rear rotors? AP 997 GT3 and Turbo rear rotor assemblies will be in stock at our warehouse tomorrow. Replacement rotors are only $359.
The Rennlist Promocode works on this item http://www.apexperformance.net/prod-2759.htm Call with any questions you may have. We are an authorized
Essex/AP/Ferodo reseller.

Protocav

Do the PFC pads still work with these rotors?

JRitt@essex

Our AP Racing discs are the exact same dimensions as the OEM GT3 discs (380x34mm), and are designed to work with pads that are identical in shape/size to the OEM pads (the OEM GT3 pads are 17mm thick). That means our AP Racing discs will work with all 17mm thick pads on the market that are designed to work with the OEM GT3 calipers and discs.

However, there are some pads on the market that have a shape very similar to OEM, but they are thicker. For example, PFC (7819.XX.19.44 .) and Pagid make some pads that are 19mm thick. Those pads will NOT work with the OEM discs, nor will they work with our AP Racing discs. They will only work with the thinner 380x32mm discs that some manufacturers sell.

Hopefully that clears things up. Thanks.

Clark-ApexPerformance

Well said Jeff..thanks.

Tom@TPC Racing

I was preparing my 997.1 GT3 for a 3-day track weekend and discovered a decent size crack on the inside of the left front rotor. My conservative judgment tells me that I could go 2 days, but I am not going to put myself and others at risk so at 3:30pm the day before the event, I gave Jeff at Essex a call to check availability on the AP Racing J-hook rotors. Jeff said they have all the pieces(friction rings, hats, hardware) in stock to send next day air but I'd have to assemble them to complete rotors. I said let's do it!

There are other reputable brands of rotors(discs or disks, however you want to call them) on the market, but personally, I am partial to the AP Racing brand from my first hand experience on performance and durability from 24-hour racing.

The track event was at Summit Point, which was only 1.5 hour from the shop. I went there on the first day for registration and drove half day at 7/10th; letting off well before braking zones. Drove back to the shop in the afternoon to do some paperwork and to pick up the rotors that was promptly delivered. To my pleasant surprise, even though Jeff said I'd to assemble the pieces they came fully assembled. Jeff had his guys scrambling to complete the rotors prior to shipping to save me time. Well done!





I like these rotors because they have spring clips to prevent knocking sound on the 2-piece floating-design at low speeds. Which I feel its important for a dual purpose car. Sure enough zero knocking sound at any speeds. This is not an issue on full-time track cars and race cars but on streets cars subjected to a lot of lower speed driving(say less than 35mph) having the spring clips will prevent unwanted wear on the aluminum hats as a result of the movement.





Here's my OCD-ness kicking in- Checking torque at 120 in/lb.





Day two, after isolated heavy rain in the morning I change the rotors.





The fit was exacting. Zero drama as expected.





Another thing I like about these rotors is the clearance between the aluminum hat and the brake pad backing plate- nicely machined!





As for the stopping performance- WOW. Using the same pads the braking feels noticeably smoother and feels like it has more grip in the middle of the braking zone(compared to the one-piece all steel rotors). I was going easy on the bedding-in session but in the later sessions I am engaging the ABS in the mid-zone from muscle memory- you can tell by the blue spots on the rotors. I have to retrain my foot for threshold.








Overall, I am very happy with the rotors and I wish I had these rotors sooner. Thank you to Jeff and Essex for coming through with my last minute request. TPC Racing will be offering Essex/AP J-Hook rotors to our customers.

Saru385

thanks for the write up, Tom!
i'll be ordering up a set of these soon. just need to check if i need new pads as well.

edit: what are you running for rears?

Clark-ApexPerformance

We have these AP Rotor assemblies in stock for both from and rear
For 997.1 and 997.2 GT3 and fronts for 991GT3. Free shipping
And Rennlist promo code apply. We also have PFC and Ferodo pads in stock.