mr.t0fu

First off I have to say, this forum, and this community is awesome. The complete AP kit is not cheap and therefore was a difficult decision to make but there were a bunch of people that helped me and answered all my questions extremely quickly, without knowing me, and when there was no benefit to them. @Shandingo was someone who took a lot of time helping me out, so thanks again to all and this community. Ok enough of that, onto the meat and potatoes.

Short Review: Buy the front kit if the complete kit is too expensive.

Long Review: A bit of background ... I wanted to put in a bit of abuse on the kit before I made any judgements and have had them out for 4 days in the past 4 weeks. I am green and slow, so take everything I say with a grain of salt. I run a 1:28/1:29 at my home track, SPR-M, and have done days there in my current car, 718 CGTS, my previous F82 M4, and E92 335.

Performance: In a word, this kit is consistent. I get the Cayman is a relatively light car but through 30 minute sessions I got absolutely zero fade, could maintain all my braking points, and even pushed the braking zones deeper toward the end of multiple sessions. In fact, my best times were the last or second to last lap after 25-30 minutes of pushing on track. Also this kit bites hard, more on this below.

Maintenance/Longevity: Pad changes are very easy, remove the pad retention bolt and clips, swap the pads and you are good to go - no need to remove the brake caliper. In total my kit has about 11 days on it - the discs look great, and the pads still have about 1.25x the thickness of the backing plate, so getting close but still some life left.

Cons: The initial bite on the kit is abrupt, it could be the pad I'm using, Ferodo 3.12, or me, but it was hard for me to get a smooth initial bite under braking; the middle is very linear and consistent; then the release, again, is a bit abrupt. I've talked to others and many people seem to share the same sentiment. We were all also running the 3.12 so as I said that could be the pad. It's not a big con, and I'm sure with more practice and time it's something that can be smoothed out but it was apparent. Finally the rear brake lines do rub, they have 2 rubber layers that protect them but the design of the ss line does cause rubbing against the inside of the wheel. Nothing gaffers tape and zip ties couldn't fix.

Fitment: I run the ever-so-popular GS1Rs in 19s and they fit great. I'm also told they will fit many a 18" wheel (not all, but many).

Final Thoughts: I love the kit, the stopping power and consistency is incredible. Throughout the track days I was consistently outbraking much better cars than mine, now if only I could out drive them ... That being said it is an expensive kit and I could see only the front kit making a lot of sense for a lot of people. If you track your car, I do think this is a must have upgrade, again the consistency, the ease of brake swaps, and the life of the consumables, make it a no brainer, for me.

Obligatory pictures:

Obligatory track pic

Front kit

Zip ties + gaffers tape make the world right

Sorry for the long post and thanks for reading!

donR

Very nice looking brake kit and I'm sure it works well. Do you have a link and what are the rotor sizes?

I'm using the OEM brakes with the Girodisc and 3.12 pads which work well for shorter sessions but I think maybe they do drop off when getting up to the 30 minute mark on tracks that are heavy on brakes.

mr.t0fu

Thanks!

Fronts: https://www.essexparts.com/ap-racing...1372mm-porsche
Rear: https://www.essexparts.com/ap-racing...boxster-cayman

The fronts are 372mm and the rears are 340mm

Edit: One thing to note, the 3.12 and DS-2500 pad (street) play nice together so they don't need the full rebed. Something to consider.

donR

Thanks for the links, I have seen this kit before and I really like the J-hook rotors and a nice increase in rotor size. Certainly a very serious motor sport kit but it will need to be added to the endless wishlist for my car!

I don't suppose you weighed the rotors? They should still be quite reasonable with the alloy hats but always interesting to see whether or not there is any weight penalty with the larger rotors.

I notice you're also running the wider 255 tire on the front 8.5" GTS rim?, which I'm thinking the wider 255 tire on the front will be my next upgrade/mod. What size are you running on the back?

mr.t0fu

I wish i did, but unfortunately I did not. Essex does say there is no weight penalty even with the larger calipers and rotors. I am actually on the Forgeline GS1R. 19x9 up front and 19x10.5 in the back. My current track setup is the RE71r 255/35/19 front and 285/35/19 in the rear. Unfortunately the RE71r is scarce these days as they are discontinued. There are a bunch of other options though depending on what you are looking for. The PS4S is a good option but pretty expensive, Federal makes a really cost effective tire (RS-RR or RS-PRO) but people will look at you funny for running them ...

donR

Oh Forgeline GS1Rs, very nice and I think the 9" is much more versitile on the front. I am still using 20" and the front is 8.5" but I think it is still wide enough for 255, but 9" is perfect.

I've heard about the issue with the RE71r . I have Cup 2s and there is a new Cup 2 Connect which is meant to be a little faster, like a Cup 2.5, but I'd also like to try Trofeo R, but not a lot to choose from in 20".

JRitt@essex

Thanks for the great review mr.t0fu! The DS3.12 has a very high mu, and some people may find them abrupt...particularly once they are heated up. They are the best choice for cars running very sticky tire compounds, and it typically takes a little time for people to get used to them. When I installed them in my C6 track car, I was a bit jumpy with them at first, was getting into ABS, etc. After my first day out there I smoothed things out. You really need to recalibrate your brain and leg to realize you don't need to pounce on the brake pedal. Gentle and smooth inputs get the job done. If you want something that is a little lower mu that require more force, the Ferodo DS1.11 is the correct choice. I'd give those a try next time. One of the great things with the Ferodo DS pad line is that they can be interchanged on the same set of discs without having to re-bed. That means you can go from their most aggressive DS3.12 down to their least aggressive DS2500 by just dropping in the pads and doing a couple hard stops to get them seated. You won't have to worry about getting judder, vibration, cross-contamination, re-bedding, etc. like you do when swapping across brands from street to track pads and back. You can see all the Ferodo DS compound descriptions here: https://www.essexparts.com/brake-pads/ferodo-brake-pads

Brake line fitment on the rear of all recent Porsches is tough. When installing them, one has to be careful as mr.t0fu notes. The problem is that everyone is running different sized wheels and tires, different suspension ride heights, different alignment settings, some have rear wheel steering...the list goes on and on. You just have to check clearance with the wheels/tires during the install, and keep an eye on them periodically by making it part of your pre-check routine when prepping your car for events.

Consistency and confidence are two of the most-used words our clients relay to us about our brake kits. They are the same all day until the last turn, regardless of how hard you are hammering. That includes on some very fast cars. Here's another customer review on a 991.2 Carrera T with 700 WHP. He's running the same kit that mr.t0fu has on his car: https://www.essexparts.com/news-blog...tion-brake-kit

donR, First off, thanks for your patronage on the Ferodo DS3.12 pads. It's unlikely though that they are dropping off during extended sessions. We've run them over 1600F on our dyno, and they are completely stable up to that point and beyond with zero fade. They're also winning races in professional GT endurance racing:https://www.essexparts.com/ferodo-ds...t-championship
You may have something else going on if your brakes aren't holding out past 30 minutes. Is your pedal getting soft at all? That would indicate a fluid issue.

We have two kit options for the front of the 718. One has a 355x32mm disc and the other kit a 372x34mm disc. The kit being reviewed here is our larger option, the 372mm. Here are the weights vs. the components on a 718 GTS:
OEM front GTS disc (330x34mm)= 21.7 lbs.
Essex/AP Racing 355x32mm disc assembled= 20.8 lbs.
Essex/AP Racing 372x34mm disc assembled= 18.9 lbs.

OEM front GTS caliper= 9.0 lbs.
Essex/AP Racing CP9661 Radi-CAL= 6.2 lbs.

As you can see, despite our considerably larger components, we actually have a small unsprung weight advantage vs. the stock brake package. Our various brake offerings can be seen here:
https://www.essexparts.com/my-vehicl...bo/Iron%20disc

mr.t0fu

Thanks for the reply Jeff @JRitt@essex ! I do want to say that Jeff was another one of those people that spent a ton of time helping me with my kit (and I didn't even buy it from them). If anyone has any questions on the kit, the installation, or just want to chat about cars in general, Jeff is the guy to talk to!

Don't get me wrong, I love the pad and the consistency throughout a session, and through the middle of the travel, is incredible. I should have been more clear, it's probably just an issue with me, but more track time will clean that up . But I may try the 1.11s, it's always nice to have more data points ...

I will add that the ss lines are very well protected, I do make it a point to check it after every event and I haven't had any more rubbing issues since I zip-tied and rewrapped with gaffers tape.

mr.t0fu

Yea not a lot of options in 20", if you go down to 19" (or even better 18's) then a lot more options open up for you. If you are in Australia, I think the RE71rs is supposed to be coming your way soon? At least that's what I heard ...

https://www.bridgestone.com.au/en/ty...rimdiameter=20

Looks like they have 255 and 285 in 20"s. You might want to give that a go and let the rest of us know how you like it

donR

Thanks, I did see the RE-71RS and they look great but in the 20" it is a 255/35 and 285/35 but I think the 285/35 is a little tall for more liking, a 285/30 would have beeen better. I think the 19" is still a better size.

mr.t0fu

Just out of curiosity, what about a 35 do you not like? Is it a performance or a cosmetic issue?

donR

Hi Jeff, thanks for the technical info. The weight saving in terms of unsprung weight looks to be quite substantial adding up to almost 6lbs per corner so no penalty there!

Regarding the DS3.12 pad performance I should have been clearer, but I'd assumed it was more the thermal limits of the OEM caliper and Rotor over longer sessions rather than the actual DS3.12 pad that was the issue. However, I am relatively new to track driving so I could not say definitively but it would be nice to try the Essex Radical Cpt brake kit for comparison! Last year I had to get my Girodiscs machined as they were slightly warped but I was running the stock pads at that stage so things must have gotten too hot and my braking is not always the best so no fault of the rotors! Since I've been running the DS3.12 pads I haven't had anymore issues with the rotors and brake feel is much better and consistent throughout the session but can get a bit squishy on longer sessions but that is on a track that's hard on brakes and tires.

The other thing I've noticed about the 4 piston caliper is the pad is smaller than other 6 piston calipers so perhaps that is another limiting factor.

Do you have a size comparison of the Ap Racing kit pads?

donR

I think it is potentially a performance issue as the 285/35/20 has a diameter of 27.85" vs the OEM size of 27.3".

Not a great difference, but I notice most track 18/19" rear wheel/tire setups for the 718 range from ~26" to 27" in diameter so quite a bit smaller.

The smaller diameter should mean better acceleration so it seems to me if anything you want to go smaller but not larger. Probably not a difference in the real world but if you are chasing fractions of seconds on the track it might make a difference.

JRitt@essex

Understood. You bring up an important point. Your brake system is only as good as the weakest link in the chain, and one of the foundations of that chain is your discs. If your brake discs run hot, your pads run hot. If your pads run hot, you are at risk of pad fade (you press the pedal and the car doesn't slow at the anticipated rate). If your pads run too hot, your caliper pistons are overheated. If your pistons get too hot the caliper body and brake fluid gets too hot, and you are at risk of boiling your fluid. It's one big chain, and a weak link can cascade into a whole bunch of problems.

The hydraulic brake system is closed, and fluid is just pushed around from one area to another, and back. The pedal only gets squishy when one of two things happen A) the system is no longer closed...you have a leak. or B) You are boiling your brake fluid boils, air bubbles are trapped in the system. Those air bubbles compress when you press the brake pedal, and it feels squishy. If you aren't running a top fluid, you should look there first if you have a soft pedal. Something like an AP Racing R3 or R4 if you're not running one of our complete brake systems (those with our systems can generally get away with running at least one tier lower of fluid, as the system doesn't get as hot). I'd consider AP Racing R2 the base level however.

You are absolutely correct about a six piston vs. four piston pad. The reason why six piston calipers are almost always the choice in racing is for the added pad volume. A six piston caliper can generally accommodate a longer and taller pad than a four piston can. Race calipers can also often accept a thicker pad, so the overall volume (L x W x H) is greater in a six piston vs. a four piston. That means you have a larger heat sink to absorb energy from each stop. Sometimes calipers can even go larger, such as an eight or ten piston. The problem with these however, is that once a pad becomes too long, it starts to exhibit some potential problems. A long backing plate is more prone to warping and cracking. What some manufacturers do is have an eight piston with two separate pads per side of the disc. There is one pad for every two pistons. This increases the number of leading pad edges and pad bite, and mitigates the issues of warpage and having the pad material come off the backing plate. If you look at the new 992 Turbo, it has a ten piston caliper. Porsche did that so they can have a very tall pad. Carbon ceramic systems in particular require a very tall pad. They run hotter than iron, so they use the added surface area to radiate heat. Rather than having a ridiculously long pad, they stack the pistons in two rows vertically. That helps keep the pad at a reasonable length while increasing surface area. Okay...probably more than you wanted to know...I get carried away sometimes.

amurph182

I have this kit on my 981 2.7, it’s fantastic. I originally upgraded the fronts because I was tired of having to take the caliper off to swap pads before and after events and the full front kit was price competitive with just swapping in open-back 997 calipers. Just the front upgrade was amazing in terms of feel and consistency. I was able to brake so much harder, later, more often that the stock rears were overheating the pads and stock-sized RS29’s were getting murdered after a weekend. So I added the rear kit and it’s just been amazing. I’ve tried to 3.12s and there’s definitely too much bite for me with RS4s and RE71s. It feels like I’m getting into ABS if I even think about touching the brakes, whereas with the 1.11s I have a lot more pedal to use before I feel like I’m locking them up. Threshold braking is hard when you’ve only got a couple inches of brake pedal to work with! Prior to this, with stock calipers and Pagid RS29’s I got great stopping power but could really stand on the brakes before they would start to lock up. To be honest, I kind of prefer that feel but it doesn’t take long to adjust and like I said it’s incredibly consistent. I’m moving up to an r-comp tire this year so it will be interesting to see how that changes braking performance.

All in all, this was a great upgrade for me in terms of performance, consistency, and, despite the price, value when you look at the other options for open-backed calipers and larger rotors. Did I mention that I can swap pads on all 4 corners in 30 min? Well worth the cost when it’s 95 degrees and humid at the track and a pad swap is the only thing between me and shade.