Brembo’s Sensify brakes are nothing short of a small revolution
It’s easy to gloss over some new braking technology called “Brembo Sensify.” On the surface, that name doesn’t mean much of anything. What this technology is for brakes in new cars, though, is nothing short of a small revolution.
When you fully depress the brake pedal of a modern car, brake pressure is distributed in the same fashion every single time. Fluid is pushed out by the master cylinder to all four corners, in turn compressing the calipers’ piston(s) and pressing the brake pads into the rotor, causing friction. On a surface level, that’s what’s going on — of course, things get a little more complicated when you introduce brake-by-wire technology, but even that is fairly normal stuff versus what Brembo Sensify is. As an indicator of how revolutionary this is going to be, brake fluid and brake lines become unnecessary with Sensify.
The best way to understand what Sensify does is to lay out an example. In an emergency stop situation involving new cars on the road today, you’re going to activate the anti-lock braking system, otherwise known as ABS. It’s a smart technology invented decades ago and has been improved ever since. The purpose is in the name. Instead of you needing to feel out and pulse the brake pedal under threshold braking to keep the wheels from locking up, the system takes care of it for you in a series of micro-pulses, applying and reducing brake pressure over and over all on its own, bringing you to the most efficient stop and allowing you to maintain some semblance of steering control. Anybody who drives, especially in wet or winter conditions, has likely felt this in action. As soon as you activate the ABS system, the pedal starts pulsing; the ABS system makes its customary noises, and you eventually grind to a halt. Hopefully.
That whole song and dance with ABS is entirely unnecessary with Brembo’s Sensify braking technology. In fact, cars with Sensify won’t even have systems like ABS or need to take advantage of traditional systems we’ve used to improve hydraulic braking systems over the years like electronic brake force distribution (EBD). To tell you why as succinctly as possible, that’s because this system is capable of applying and retracting brake pressure to any wheel independently of another with practically instantaneous response. It replaces all of these innovations — ABS, EBD etc. — we’ve made to improve hydraulic-based systems with a single new system that can do everything quicker.
To use an analogy, Sensify is like hub motors for electric cars, but instead of accelerative control, Brembo has total decelerative control. In the case of emergency stops that would otherwise use ABS, the Sensify system is able to bring you to a halt by utilizing a large array of sensors and a combination of new braking system hardware consisting of new caliper, brake “line” and brake actuation technology. In a full emergency stop, those sensors are able to suss out the maximum performance of the tire, and get the brakes to apply the exact amount of pressure that provides the quickest stopping distance without the ABS micro-pulses. It’s smooth, calm and silent sailing from whatever speed you’re at, to 0 mph.
The mechanics of the system are even massively different from brakes in new cars today, and there are multiple setups that Brembo is offering. The most advanced setup uses electro-mechanical calipers at all four corners. These calipers are actuated by tiny electric motors that squeeze the pads onto the rotor when you press the brake pedal. Your brake pedal is essentially just an electric button in this case, sending a signal out to an ECU that in turn tells the brake calipers what to do. There are no traditional brake “lines” here, and because an electric motor is used as the actuator, there’s no brake fluid either. You may be asking, where’s the backup system in this setup in case of a loss of power to the car? Brembo says that vehicles with a full electro-mechanical braking system will come with a backup power supply that will be utilized in such situations.
There’s a hybrid system available in the Brembo Sensify brake lineup, too. This system uses the electro-mechanical brakes for the rear, but the front brakes are hydraulically actuated. Even this traditional-sounding hydraulic front system is different than the usual, though, as each front caliper will have its own master cylinder. That creates two closed braking systems for each front wheel. Its mechanics are much more akin to the brake-by-wire systems found in cars today, but Brembo is still able to have full, independent electric control of each caliper because of the closed systems. As you’d expect, the front calipers use brake fluid.
We got to try this system out in a Tesla Model 3 Performance to see if all the work Brembo has put in over the past 10 years — yes, 10 years of development — was worth it. Brembo set up a number of events and obstacles on the Michelin Proving Grounds, then set us loose in both a Model 3 Performance using its current braking system, followed by time spent in a Model 3 Performance with the Sensify system installed. The difference was shocking.
The first emergency stop — and every stop thereafter — we made in the Sensify car was almost serene. Going from 0-100% brake pedal pressure in a car with traditional brakes always results in some tire screeching, ABS racket and maybe a little drifting to one side or the other as you try to bring the car to a halt. With Sensify, Brembo’s sensors aim to keep brake pressure at the point where you’re using as much grip as the tires can afford you, without locking the wheels up for even a fraction of a second. You’re simply hauled down from highway speeds to 0 mph like you’re going for a leisurely stroll. When Brembo showed us the computer data afterwards, the brake pressure graphs didn’t lie. Instead of constantly micro-adjusting brake pressure like an ABS panic stop would induce, brake pressure in the Sensify car was even and consistent from the beginning to the end of the stop. This was the case on both dry and wet pavement.
Jamming on the brakes mid-corner is a recipe for disaster in many cases, and while the ABS system in the Model 3 Performance handled this obstacle with ease, the Sensify system did it even better. We were able to continue tracing our line in the corner without any issue, and the computer did an excellent job of ensuring the car remained steady and predictable under heavy braking. Even when you’re going quickly enough that a touch of understeer is the car’s first direction, you can quickly remedy that with steering force that is helped by the braking patterns. Brembo even had us intentionally upset the vehicle by applying full brake force at 75 mph in a curve, then jerking the wheel left and right. There wasn’t even a hint of an out-of-control feeling. After that stop, Brembo presented the data explaining that the car would oscillate brake pressure on the left rear and right rear brakes individually with each yank of the wheel to one direction or the other in an effort to keep the car under control. We’ll also note that all of these maneuvers were done with stability control completely defeated and in the Model 3 Performance’s “Track Mode.”
The final maneuver Brembo threw at us was a quick left-right that was to be completed under heavy braking from fairly high speed. Once again, the Sensify car outperformed the traditional-braking Model 3 Performance in both maneuverability and control. Depending on the severity of the steering angle you apply under braking, the system will even aid you with the smallest dab of oversteer to help guide the rear end around controllably through a corner.
Brembo isn’t throwing any quantifiable improvements in braking distance at the wall yet, but engineers say that’s largely because the system is still in testing. An easier way to get better stopping distances out of a car is to just upgrade the tires. Sensify comes with lots of other positives outside of extra-smooth stops and independent brake control, though. For one, it’s a big win in packaging, as it gives OEMs more freedom with their platform and electrical architecture design. You no longer need to run brake lines throughout the car, and the ABS system can be trashed. Similar to today’s brake-by-wire systems, you can also adjust the braking feel and response. A “comfort” brake mode would leave you with a soft and progressive pedal, while a “track” brake mode could provide a super-stiff and sensitive pedal feel.
There are some big innovations here when it comes to efficiency, too. Brembo designed a new spring for its electro-mechanical brake calipers that it calls “Enesys,” which is able to more fully remove the pad from the rotor when you’re off the brakes, thereby decreasing drag. This reduces rolling resistance, which is of paramount importance for EV range. On top of that, your pads will last longer. Another plus for EVs is the regenerative braking potential — Brembo says it’s able to recuperate more energy with the Sensify braking system than a traditional one. However, that energy recuperation is not without energy use, because you’ll need to use battery energy to run the caliper motors.
Total weight of the system is another zero-sum game. The added weight of the motors, sensors and other components cancel out the lost weight of deleting brake lines, the master cylinder and other traditional braking system parts. That added weight is also in a place where you really don’t want it — hanging off the wheel. This extra un-sprung poundage from the electro-mechanical brakes is exactly why Brembo believes that the best application for sports cars and supercars will be the previously described hybrid setup that keeps un-sprung weight similar to what a traditional braking system would be.
Lastly, and here’s where some skepticism is necessary, Brembo claims its electro-mechanical calipers are a lifetime part. Anybody with older vehicles will tell you that they’ve gone through their fair share of calipers over the years, but Brembo says the only parts you’ll ever need to replace are the pads and rotors. Of course, the hybrid setup that uses brake fluid and short brake lines in front will require servicing of the brake fluid, too. Brembo says you can use any pad or brake fluid you desire.
Once the Sensify braking system is out there and on production cars, Brembo says it can update and “improve” it via over-the-air updates. We asked why a braking system would need to be updated, and Brembo reps told us that it gives OEMs an opportunity to sell access to a towing brake package or racetrack braking software package (or any package they can dream up) as an after-sale item. If you thought we were entering subscription hell already, just wait and see what will come next. As for when you should expect Sensify to show up in production cars, Brembo says it’s working with a number of OEMs right now, and the earliest examples of it are scheduled for 2024 sale. As for which OEMs and which models, Brembo is remaining tight-lipped about as it finalizes Sensify tuning.
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