Can twin discs stop close shaves?

I Have a Razor Like That

True, Delphi's Maximum Torque Braking (MTB) concept does look like the auto industry's version of the multi-blade razor. But the concept is more akin to splitting a ventilated disc brake in half, gutting the fins, and placing a pair of pads in the void. This increases the cooling and friction surfaces from two to four, reduces thermal stress on the wheel hub and brake, and increases the options for tuning or enhancing the performance of the braking system. Which means you can run a brake similar in size to what you have on your vehicle today and get 1.7 times the torque output, or substantially downsize the whole system and match the performance of your current design.

What Else Does It Do?

Delphi's engineering team in Leamington, U.K., say MTB requires about half the application pressure of a conventional design. Which means the brake booster can be downsized such that it would liberate precious under-hood space, and cut about 1 kg in weight. Conversely, retaining a larger booster would allow engineers to reduce pedal effort and travel. Also, disc diameter could be reduced by as much as 25 mm, so smaller, less expensive wheels could be fitted. For SUVs, this also means using higher aspect ratio tires wouldn't necessitate larger fender wells. And, because the discs float on the hub, lateral run-out isn't a problem. Judder and squeal from tolerance stack-up is eliminated, and stability programs can be retuned because MTB doesn't struggle as much against engine torque as do conventional brake designs.

Where Would I Use It?

One place would be a high-performance SUV or sport sedan. Delphi claims MTB greatly reduces brake fade, including during Europe's 12-stop fade test. And its lower brake application pressure means shorter stopping distances should the booster fail. Testing also indicates a 100[degrees]C reduction in maximum brake operating temperature. Further, if the current brake booster is retained, pedal travel can be cut by 25 mm. If downsizing is needed, 40 mm can be taken out of the booster size. Depending on brake system specification and the level of integration, Delphi says an MTB system can be made up to 7 kg lighter than a current braking system.

[ILLUSTRATION OMITTED]

Nice Idea. Does It Work?

Twenty vehicles have covered over 1.5 million kilometers in testing, and two fully engineered systems have been shown to OEMs. The first is a small European B-class car with the caliper piston integrated into the suspension knuckle. The second is a high-performance SUV with a stand-alone piston architecture that shows what an OEM could do for a mid-cycle upgrade. Delphi stresses the system uses conventional materials and processes, and that cost and complexity can be reduced even further by using a one-piece wheel hub with a press-fit wheel bearing. Delphi has an analysis program that models whole-vehicle tests to cut optimization time.

By Christopher A. Sawyer, Executive Editor