Disc brake technology has been around since the early 1900s, but was not widely used because of the lack of technological progress in the automotive industry. In the 1950s, the progress was there, and automakers were starting to use the new braking technology. Jaguar equipped their cars with disc brakes for the 1953 24 Hours of Le Mans and won, with a large amount of credit given to the brakes.
Fast forward to 2015, and virtually every new car on the is equipped with disc brakes. Why? Compared to drum brakes, disc brakes offer significantly better stopping performance, especially on the track, because the disc is readily cooled, as to where a drum brake traps heat and pad material. For Project LS350Z, we needed some new brake rotors to renew the stopping power the car once had, and rotors that could take the beating of track days, so we got in touch with DBA USA and they sent over a set of their T3 4000 Series rotors for us to install.
We also sat down with Yoni Kellman of DBA USA to talk about the rotors and the technology behind them, as well as some other rotor applications DBA USA offers for the 350Z
DBA’s 4000 Series T3 slotted brake rotors were designed to handle extreme road and race applications, which really caught our eye because Project LS350Z will be driven on both the street and the track. Made out of cast-iron and a unique blend of additives, the 4000 Series rotors has a better resistance to sharp temperature changes than typical Grey cast iron material. According to DBA, in addition to having better resistance to sharp temperature changes, the rotors have a high surface hardness, and high resistance to cracking and other various distortions.
“Those are our bread-and-butter rotors. The 4000 Series rotors have all of our technology in them, but still remain cost-effective,” Kellman said.
DBA’s mixture offers a higher FC200 rating, compared to the FC150 rating of the standard Grey cast iron OE-type material. And for those that didn’t know, the FC ratings are used as a measurement of the strength of cast iron.
Ventilation is a key factor for DBA’s rotor design. Vented rotors have fins sandwiched between the two clamping surfaces to extract heat that builds up under braking. The fins also act as an internal structure for the rotor. Most rotors either have have a straight vane or a curved vane. The straight vane is good for airflow, just not while the rotor is spinning. The curved vane is the better choice of the two because at high speeds, the curved vanes act as fan blades that extract the hot air. DBA’s Kangaroo Paw technology is a lot different, and it’s quite the game-changer.
“Our Kangaroo Paw technology has more surface area than a curved or straight vane does, so when air flows through the rotor, it can extract more heat because its coming in contact with more of the rotor’s surface,” Kellman explained. “Having these vanes spaced equally throughout the rotor also makes it more rigid. They distribute the load across the two rotor faces more evenly, and it really helps fight off distortion.”
If you’re wondering what the three markings are on the outermost part of the rotor, those are thermo-graphic paint markings. The thermo-graphic paint changes color when specific temperature thresholds are achieved, making it quick and easy for the driver to monitor braking performance. The three initial colors marked on the rotor include green, orange, and red.
“What our paint markings do is allow you to tune your brake setup to an extent. You can see how hot your rotors are getting to match your brake pads, because every brake pad has an ideal operating temperature range,” explained Kellman. “If you look at the markings on the rotor to see how hot it got, you can find the pad that encompasses the same heat range.”
These paint markings aren’t like your heat-sensitive t-shirts or coffee mugs, though, because they don’t change back to their original color. Once the colors change, they stay the same color for the rest of the rotor’s life.
The 4000 Series rotors have all of our technology in them, but still remain cost-effective. – Yoni Kellman, DBA USA
With DBA offering both cross-drilled and slotted rotors and slotted rotors, we were curious as to what the real differences in performance were.
“When it comes to a race application, slotting is the way to go,” Kellman admits. “There are far fewer issues with cracking when the rotor isn’t drilled. Basically, as time has gone on, we’ve learned that drilling was the right idea back in the day, but slotting accomplishes the same tasks and more, with fewer drawbacks.”
Installing new brake rotors is a pretty easy task and can be done at home in a matter of hours using a jack, jack stands, a ratchet, and a few sockets. We’re lucky enough to have a few Bendpak two-post lifts in our shop, but before we got the car on the lift, we installed our trusty Racelogic PerformanceBox and set out to get some 60-0 mph numbers with the stock brakes.
Before we put the car in the air, we broke the lug nuts loose, and then proceeded to remove the wheels once the car was in the air. Our 350Z wasn’t optioned with the Brembo package, so we’ll be working with the standard slide calipers that the car came with. We couldn’t just replace the rotors and leave the old pads on, so we got some Hawk HPS pads for all four corners that should give a nice bite.
With a car over ten years old, there is a possibility that some components need replacing, which gave us a good reason to do a quick once-over before we started removing the calipers. To our surprise, Project LS350Z passed our visual inspection and we set to work. As there’s no specific way to go about changing rotors and pads, we started from the front end and worked our way to the rear.
For starters, we removed the slide bolts to remove the part of the caliper that houses the piston. After the piston was removed, we simply slid the brake pads out of the caliper frame. The last step we took to getting the caliper frame off was removing the two bolts that hold it to the knuckle. Once the caliper assembly was completely removed, we were finally able to take those worn rotors off and slap on the brand new DBA 4000 Series slotted rotors and Hawk HPS pads.
With the new rotor on, we installed the caliper back on the car in the reverse order we took it off and repeated that process on the other three corners. Installing these rotors was definitely one of the easiest installs we’ve done in our shop, but it was also one of the most crucial to Project LS350Z.
Overall, the car feels great with the DBA 4000 Series slotted rotors and Hawk HPS pads. With only rotors and pads installed, Project LS350Z is a lot more confidence-inspiring. The pedal feel and overall bite of the combination feels great on the road, but out on the track, it’s a whole different animal. One big thing we noticed when driving the car is that the new brakes take a little longer to heat up, but take significantly longer to fade. Exactly what we wanted.
When we compared our before numbers and after numbers, we were very pleased with the improvement in our 350Z’s braking performance. We conducted the test by getting the car up to 60 mph in a safe area, then slamming on the brakes, and repeating the process a few more times. Our DBA/Hawk brake combo resulted in an average stopping distance of 137.78 feet, compared to the stock brakes that averaged out to 143.38 feet; a 5.6-foot reduction in our stopping distance. Keep in mind that these brake tests are performed back-to-back, which isn’t realistic to what you’d normally see on an open track environment. There’s no doubt that the DBA rotors will help keep brake fade to a minimum over the course of an open track session.
Now that our braking performance is up to snuff, our major limiting factor in handling would be tires and further suspension upgrades. Don’t worry, though; we’ll keep you updated on our 350Z’s performance as we daily drive it, autocross it, and track it. A lot of good stuff is coming up for this build, so stay tuned for a lot of updates over the next few months.