When it comes to cars, most of us immediately associate the word performance with horsepower. The majority of modifications we make to our Fords is done to increase the power of the engine, and hence make the car faster. No one would immediately associate the term performance with making the car..gasp...slower. What we're talking about is the braking system. Unless you are an open track or autocross racer you probably have not paid serious attention to your brakes. Most people replace the pads and shoes as necessary, perhaps flush the master cylinder every couple years, and so long as the car eventually comes to a stop no more thought is put into the brakes. But when you think about it, the factory braking system is only meant to handle so much power. Once you've added a good 100 horsepower to your engine the stock braking system is simply not going to be able to haul the action down in a safe amount of time. Combine this with the fact that your stock brakes are probably worn and not functioning as effectively as they were when new, you're left with a mediocre stopping power at best, and a downright scary system at worst.

We decided to look into brake upgrades for our '88 Mustang, mainly because our stock brakes desperately needed some attention, but also because being able to slow down quickly is a big part of autocrossing, which is what we've got planned for the '88. We quickly found that our options were slim and expensive. We didn't want to drop a couple grand on a Wilwood or Baer four-wheel disc brake setup, and the fact is most people would rather spend their money to go faster not stop shorter.

Another popular option (for 88-93 mustangs) is swapping in a larger SVO master cylinder and 73mm calipers from a Lincoln or T-Bird. While this can be done for cheap, the results are not all that impressive -more clamping force on the stock 10" rotors only leads to quick lockup, which is not desirable under hard braking or panic stops.

What we wanted was an affordable brake upgrade that would significantly reduce braking distance, resist fade, but not require messing around with caliper and master-cylinder combinations. A fellow autocrosser suggested we looking to GTRotors by Grob-Till Industries, a company which sells modified stock rotors and drums, along with carbon-metallic pads.

David Grob, the "G" in GTRotors, has been in the high-performance brake business since day one. In fact he helped design the first disc brakes for Nascar. Needless to say he understands the complexities involved with designing powerful brakes. The concept behind GTRotors was to offer some of the benefits of the more expensive brake packages, at affordable prices and without the need to deviate from the stock hydraulics. Grob-Till came up with the "dimpled" rotor concept, which dramatically increases braking performance, resists fade, and increases pad life. Furthermore the dimples, unlike drilled rotors, do not weaken the rotor which leads to cracks and warpage.

The precisely placed CNC machined dimples serve several key purposes; first they increase the friction coefficient between the pad and disc. The pad "bites" on the leading and trailing edges of dimple, in addition the non-dimpled area experiences more pressure per square-inch which leads to increased friction.

In addition the dimples serve as a reservoir for spent pad material and gasses, which means resistance to glazing and fading. Brake fade is the most common problem during performance driving. Brake fade occurs for several reasons. All friction materials have an optimal working temperature where the coefficient of friction is the highest. When the temperature exceeds the point of maximum friction the coefficient of friction curve starts to decline. At a certain temperature, certain elements of the pad can melt or smear causing a glazed pad. At really high temperatures the friction material, as well as resins used to bind the material, can vaporize creating a gas. This phenomenon, knows as "out gassing" results in the pad hydroplaning on a layer of gas between the pad and rotor. The dimples serve to remove this material and gas from the friction surfaces, preventing dangerous fade conditions.

The GTDrums utilize a similar technology, but instead of dimples they are grooved. Two crisscrossing tracks are milled around the machined surface of the drum, and serve to increase friction coefficient between the shoe and drum in the same way as the dimpled rotors.

We decided to order up a disc and drum brake kit. We were truely impressed with the performance, quality and affordability of the products. For under $500 you get new dimpled rotors (high quality US iron), new slotted drums, and metallic pads and shoes. Installation took about three hours, and braking has improved dramatically. [more]