My good friends over at Endless USA, specifically Dominic Chen, wrote this pretty comprehensive write up on the new Nissan GT-R’s brake system. Take a read. Lots of technical information contained within.

With a good portion of my time recently devoted to R35 brake solutions, I figured I’d post as much as I could so that all of the facts and key points are in one place. It makes it easier for me to remember everything and hopefully some of you will find it useful or at least interesting.

Let’s start with a look at the factory system:

The OE brakes are Brembo monoblocks and the OE rotors are roughly 15″ drilled 2-piece floating discs.

First of all, do NOT confuse the R35’s OE Brembo monoblocks with Brembo’s aftermarket monoblocks. OE Brembo does NOT equal aftermarket Brembo. The aesthetics and painted logo are just about all that the two have in common.

I’ve seen various GTR forums complain about the high price of the Endless brake system for the R35. Yes, at $13,500, it’s a lot of money. I won’t be preposterous and deny that fact. However, what people must realize is what they’re starting out with exactly vs. what they’re buying. Remember that Endless is a racing company which produces racing product. Keep that in mind when you read what ensues.

The OE Brembo’s on the R35 are monoblocks, yes, but they aren’t very high in rigidity, which is extremely important when talking about high performance calipers. The OE Brembo’s are more than capable for street and light track, but aren’t truly meant for heavy racing. This is why we can’t recommend any of our racing compounds (stuff you’ve never heard of before like N30C, PC138, N35S etc) for use with the OE Brembos.

The OE Brembo’s will actually overheat before our pads will (which is somewhat dangerous) and because they aren’t very rigid, they aren’t able to get good bite out of the hard race compounds. However, since the OE Brembo’s are monoblocks, the overheating issue isn’t too much of a safety concern, you just lose brake performance. If, on the other hand, you drastically overheated 2-piece calipers, the calipers could suddenly split apart and you’d lose brakes entirely.

The Endless Mono-6 calipers are extremely light (weighing just over 7lbs each) and extremely high in rigidity. For all you forged fanatics; yes, they’re forged. So, with the higher rigidity, the Mono-6 calipers actually have the ability to generate good bite characteristics with our race pads as well as operate in the extreme race conditions without worrying about caliper fade (overheating the caliper).

Another demerit to the OE system is the fact that the rotors are cross-drilled. Putting aside the cross-drilled-rotors-have-a-tendency-to-crack debate, the issue with them is that they cool too quickly for track conditions. This is a fact that even Brembo themselves will tell you. With rotors that cool too quickly, you get erratic temperatures which cause rotors, both cross-drilled and slotted, to crack.

Also, the inability to maintain a good temperature means that you can potentially drop in and out of the ideal temperature range for whatever brake pad you’re using. The fact that the OE rotors are 2-piece floating allow for the rotor and bell housing to expand with heat, which is good, but the fact of the matter is that the surface of cross-drilled rotors is cooling too quickly.

This is why all our rotors are always ONLY slotted. And in case you’re wondering about the curved slots or little E’s that you see in the picture, they’re there to generate higher friction levels than standard slots do.

Yes, E’s for Endless.

No, I’m not kidding.

No, it wasn’t my idea.

So, yes our brake system costs a pretty penny, but it’s for serious RACE use. Do you need it? Maybe not. Most of you will be just fine with some of our track pads like the ME20 and some RF-650 brake fluid.

For those curious, the ME20 compound has an ideal temperature range of 300 ~ 800C within which it exhibits a coefficient of friction between 0.35 ~ 0.40. Yes, 300C is high for a starting temp, but the pads reach that temperature very quickly.

Did I just say brake fluid? Yes, don’t forget about brake fluid.

I’ve noticed that most tuner guys run Motul RBF600 for whatever reason. Perhaps they have a good marketing guy or something. Motul’s fine in terms of boiling points but so are AP600 and Castrol SRF. Bet you guys never heard of Castrol SRF even though it’s been the leading brake fluid for race teams for the past few decades. Am I right?

BUT, what you guys have to pay attention to in addition to boiling points is stuff like boiling point with water content or compressibility. Why? Because racing brake fluids absorb more water than street fluids do. And I’ll get to compressibility in a sec.

Here’s a graph of boiling points according to water content. Our RF-650 and the AP600 are very stable, with the RF-650 being a bit better. However, the SRF drops off violently when you get water in it. This means you can keep the RF-650 in there longer without having to do a full flush in fear of having water in the system. Water in the system means it’ll boil giving you a spongy brake pedal.

Now the other issue; compressibility. With our RF-650 brake fluid being standard original equipment on all Porsche GT3 Cup cars (Yes. Standard equipment from Porsche.), a lot of various teams in the US have been in close contact with me regarding it. Most have never heard of it before Porsche started using it as an OE part 2 years ago. Most of them had been using Castrol SRF (I told you it’s been the leading fluid for decades).

What these GT3 Cup car teams have been telling me is that they’d put the fluid in the system, bleed it, and then go out on track. 5 or 10 minutes into the session the drivers would report the brake pedal feeling soft. So, they’d bring the cars in and check for air only to find none in the system. The actual issue ended up being compressibility. In short, different brake fluids compress more than others which accounted for the drivers reporting a soft pedal.

The teams tried a bunch of different fluids before realizing they should try ours (reason being they had never heard of Endless and they didn’t know where to get it). The teams tried AP, Motul, and others even I had never heard of, all still ending up with the same issue. Finally, when the GT3 Cup cars ran at the Formula 1 Grand Prix in Canada, they talked to the F1 teams. What they found out is that there are only two brake fluids used in Formula 1; one being Endless. Turns out the Brembo fluid and ours are the only ones without severe compressibility issues. And no, you’re GTR isn’t factory equipped with the Brembo fluid.

There are other issues with the fluid that I won’t get into, such as the viscosity with various water contents at various temperatures, or the actual shelf-life and water absorption over time of each fluid. In each case, the RF-650 was superb. I have graphs in case someone is actually interested.

Super long post, but the messages that people should take from this are the following:

1. Your factory Brembos are more than adequate for street / light track use. Our MX-72 is a good street / light track pad that would ensure good performance.

2. For some moderate track use, replace your pads, rotors and fluid. The OE rotors don’t hold up well over time and they’re very expensive to replace. We’ve developed Endless OE sized rotors for the R35, but haven’t set pricing yet. Should be out soon.

3. Our R35 brake system was designed specifically for extensive race use. That is why it carries a high price tag. Not because we’re greedy bastards who sit high on a pedestal thinking we rule the world. You only need it if you’re going to be racing.

Edit: Mr. Sean Morris brought up a great point in the comments section that I neglected to mention: brake ducting. If you’re actually racing your GTR, brake ducting is something that should definitely be considered. As Sean pointed out, even aftermarket racing brakes can only evacuate so much heat before they too overheat. On any serious race car and you’ll more than likely see multiple air ducts to the brakes and also intake system, oil coolers, etc.

Notice the ducting to the Mono-6 on the Super GT Wedsport IS. In hindsight, I didn’t mention ducting in my original post, but I would most certainly hope that anyone racing their GTR (or any car for that matter) would not have to be reminded about ducting. I don’t think it really pertains to the audience of this post (who knows, maybe it does), but it is definitely an integral part to any racing brake system.

Just remember the ideal operating temperature of whatever products you’re using and adjust your system accordingly. When Risi Competizione was testing, they had to block off a good amount of their brake ducting to maintain a high enough temperature for a particular Endless compound. Ultimately, I switched them to a different compound which eliminated that issue, but the lesson to take from it is to know what temperatures your system needs to run and ensure that it does so.