AP Racing brake systems in development

[Dave-ROR]

Some engineer friends appreciated the correctly sized NAS fasteners used.

<< had no idea what they were talking about

[OrbitalEllipses]

Originally Posted by Dave-ROR

Some engineer friends appreciated the correctly sized NAS fasteners used.

<< had no idea what they were talking about

I believe they're talking about the bolts connecting that Al hat to the Fe disc.

[Dave-ROR]

Originally Posted by OrbitalEllipses

I believe they're talking about the bolts connecting that Al hat to the Fe disc.

Well yeah I knew that part

[OrbitalEllipses]

Originally Posted by Dave-ROR

Well yeah I knew that part

That was a test. You passed.

[Matt Andrews]

I did a more complete write up of my track review of the Essex kit on my blog. Here is the text:

I’m sitting on a worn pleather seat at 10,000ft above sea level. I’m loosing the battle for the armrest. I’ve spent way more time in this uncomfortable seat than I care to think about in the last couple weeks since I installed the Essex brake kit on the FR-S. I’ve gotten a lot of emails and PM’s asking for track feedback. I need to edit the video of the day at Autoclub Speedway in Fontana. The best footage I have was unfortunately interrupted by the now infamous McLaren loosing a fight with a cement retaining wall. This is basically a really elaborate excuse for a blog post without a ton of pictures and video to back it up.

In previous posts, I suggested that the biggest advantage of the Essex brake kit was the 20lbs it sheds. And this is indeed a big advantage. I changed over to these brakes before I tested the limits of the stock system. But I have watched others on track with me or that post online, and it has become pretty clear that the stock braking system can not handle a lot of track duty. Rotors show significant ware after a couple days (I know of 2 that have cracked on the 5th and 6th track days). And pads aren’t lasting that long. A set of XP10 Carbotechs lasted a friend 3 track days. I would expect that on a heavy car, but this surprised me here. The cost of consumables in the brake system is higher than I anticipated on this car. If you decide to keep the stock brakes for a while and you visit the track frequently, you need to set up a duct system to try and see if you can get some more life out of the stock parts.

My initial impressions of the Essex brakes are as follows:

You can feel the loss of 20lbs of unsprung weight. Turn in is a bit more crisp, and steering feedback is improved. This is important for me as the addition of 255s did make the steering a bit more numb than stock. The stock liveliness has now returned, but now with monster grip. The stock pedal felt great before you got a lot heat into the system. But as temps went up, a numbness crept in that while the brakes were effective, it was hard to tell when ABS was engaging and when you were simply at the threshold. Earlier I suggested this was tread squirm on the Hankook RS3’s. This was only partially true. The Essex brakes allow for the same great pedal feel and articulation of the cool stock brakes to be carried deeper into the on track session. The tires do overheat and don’t like to communicate under threshold braking like a proper race tire does. But the larger system retains pedal feel that was lost in the OEM configuration. I look forward to trying a treaded R comp tire to fully understand what is tire feedback and what is brake system sensitivity. I suspect the Essex kit will further distance itself from the stock system with proper rubber. While I did not have heat paint on rotors or stickers on the calipers, it is pretty evident that these brakes stay cooler than the stock units which will lead to extended life of parts.

Brake bias is similar to stock. I am running AP C300 pads in the front (Essex recommended) and Carbotech XP8 in the rear (not Essex recommended). Essex recommends a balanced approach to pads running the same front and rear. The hot setup on miatas is different than that, and its what I tried. I think I could fine tune the system with a pad change, but here are my current observations. There is more front bias than when I was running stock fronts with Carbotech XP10s. For street driving or novice track driving, this is a fine combo. There is a hair more front bias with the current pad set up than I prefer in a race car in the dry. But I suspect in the rain, this is just how I would have things adjusted. I believe I will swap the rear pads to something with a higher coefficient of friction in the near future. I like a car that will rotate quickly under trail braking, and I don’t mind if it is a little twitchy making transitions on different types of pavement while threshold braking. You aren’t likely to spin a FR-S with this kit and pad set up under braking. The way the car is setup now is easy to drive, it just might not be extracting all of the potential out of the system as the rear brakes aren’t doing as much work as they could.

A pleasant bonus for this upgrade is how it interacts with the ABS system. The stock ABS system in the FR-S rivals that of the S2000, which in my opinion is one of the best systems available in reasonably priced sports cars. And the Essex caliper and piston choices I think have improved upon it. With a little practice, you can feel the ABS engagement point, and it is easy to modulate in and out of its use which when the OEM units got hot became difficult to do. ABS engagement doesn’t upset the car and its not so violent that it interrupts your concentration.

The only thing that caught me a little unprepared is the wrench required to bleed your fluid. The recess in which the bleeder sits has ridges around it that require a very thin crescent wrench. A standard one won’t allow you to effectively open and close the nipple. If this however is the biggest issue I can find with the brake kit, this is going to be a success. $2500 for 20 lbs of unsprung weight falls into the “bargain” category when it comes to performance weight loss. Now if someone would only offer a 2 piece rotor for the rear.

So in current configuration, at Autoclub Speedway’s oval, the car turned 2:01′s in the morning session. Its probably a sub 2 minute car when you tighten the nut behind the wheel a little. Considering the car can be driven with the gas pedal all the way on the floor through the banking and the car never goes more than 122mi/hr, that is pretty quick. It could use a little more power. I’ve got a short video ready to upload once I get to a larger bandwidth connection.

[jamal]

Originally Posted by mines13

This could have been a manufacturing defect or fluke, but I had been warned of this possibility a couple of month ago by Endless. They apparently had experienced issues with the OEM calipers leaking under hard track use during compound testing in Japan. I sort of blew this off as I had never heard of an OEM brand new caliper failing so quickly under any sort of track use... I had about 6 track days on the OEM calipers before the big failure. I noticed a little weeping around the seals on the passenger AND driver side calipers when I swapped over to the DS2500 pads, but being that there was little I could do about it, the day before my next event; I had let it ride... That was my path to stepping up to the Essex kit. I just do not wish to deal with this issue again. I will fully disclose that I had blown 3 calipers on my old Integra at Watkins Glen, but they had 140,000 miles on them so hardly a manufacturing or engineering issue.

Have to say I'm pretty surprised by this, as well as some reports of cracked stock rotors. The heavier and more powerful WRX has had these brakes since 02 and I've never heard of this happening. Plus a DS2500 is not even a true race pad.

[JRitt]

Thanks for the track review Matt! I'm glad they're working so well for you.:happy0180:

Important Note on Brake Line Install
I had a customer installing his brake kit contact me about the brake lines. I wanted to share this info so others don't have any issues. He was concerned that the female thread depth on the Spiegler brake lines was too long at the hard line connection to the car. It isn't. Here's the skinny:

When the hard line on the car is attached to the stock brake lines, about half of the threads on the factory male fitting remain exposed. As a result, the threads of the male fitting may have a good bit of gooey black undercoating on them. Before installing the Spiegler brake lines, make sure all of that black gunk is removed, and the threads on the factory hard line are completely clean.

Once that gunk is removed, the lines will seal properly. The female fitting on the Spiegler lines included in our system are substantially deeper than the stock ones. The hard line will thread completely into the Spiegler line, and there will not be any threads remaining exposed. To say it another way, the hard line "screws further" into the Spiegler brake line than it does into the factory line.

Hopefully that makes sense, but feel free to ask any questions. We will make note of this on the revised version of our install manual. Thanks.

[mines13]

Originally Posted by jamal

Have to say I'm pretty surprised by this, as well as some reports of cracked stock rotors. The heavier and more powerful WRX has had these brakes since 02 and I've never heard of this happening. Plus a DS2500 is not even a true race pad.

The DS2500 is no more then an aggressive street pad. I was surprised both to hear AND experience this; but it did indeed happen.

[JRitt]

Had some back and forth on Enkei RPF1 wheel fitment with a customer today. Please check out the details on our blog.

Enkei RPF1 17x8 +45 Plenty of clearance on both our Sprint and Endurance packages without a spacer.

Enkei RPF1 17x9 +45 Will NOT clear either of our Competition Brake Systems without a spacer.

Big ups to forum member Uncle Fester for jumping on the grenade on this one in the name of science!:happy0180:

[Dave-ROR]

Glad I'm running the 17x8s

[Matt Andrews]

that is good to know. I wasn't even considering fitment might be an issue when I was looking at those wheels...

[03Z33]

I have both 17x8 and 17x9 RPF1's here and some 5MM and 10MM spacers so I'll post up when the brake kit arrives what spacer it will take to fit the 9's

The RPF1 in 17x9 is ~0.5 LBS lighter than the 17x8 due to the spoke design and smaller mounting pad. You can run them with spacers and still come out lighter than the 17x8 setup.

Any ETA on the DS2500 front pads?

[Ro_Ja]

Originally Posted by JRitt

Enkei RPF1 17x9 +45 Will NOT clear either of our Competition Brake Systems without a spacer.

Ugh. Is the issue with just the Enkei wheels in that size? I hope 17x9 CE28s or TC105Ns are no problem...

[JRitt]

Originally Posted by Ro_Ja

Ugh. Is the issue with just the Enkei wheels in that size? I hope 17x9 CE28s or TC105Ns are no problem...

It is just that one enkei model in that one size. The point is, every wheel is different and should be checked...assumptions about brake clearance are a bad idea!