Project GD STI- Getting it Slowed Down with Stoptech


The Stoptech STR caliper has a bridge assembly, (the black part in this picture) which greatly increases the stiffness of the caliper. The steel bolts holding the bridge together also greatly contribute to stiffness. The silver things bolted to the bridge are anti rattle clips.  They preload the brake pads, reducing noise and brake squeal.  Note the CNC milling of the caliper that reduces weight making the STR caliper weigh about 20% less than the standard Stoptech ST-60 caliper.
Unlike most race calipers STR calipers are equipped with special high temperature silicon piston dust boots to protect the seals from brake dust during extended street use.  Normally race calipers don't have dust boots because they usually end up getting oxidized and hardened from heat and race calipers are maintained frequently.  Unfortunately street calipers are usually not maintained as well and corrosive brake dust, dirt and debris often get to where they can abrade the seals and corrode the pistons on a racing caliper causing leaks. The STR calipers are equipped with stainless steel abutments that the brake pad backing plates can ride upon to prevent them from gouging into the softer aluminum caliper body in long term use.  The smooth hard stainless also makes the brake action smoother with a more consistent pedal as the pads can move more freely when the brakes are applied.

Due to some odd factors, like the integral parking brake built into the rotor, it is very difficult to upgrade the STI's rear brakes, we will explain about that a little later.  Since we could not go big, we decided to use heavy duty Powerslot OEM replacement rotors.  These are high quality, high performance rotors of the stock dimensions.  You can see here that the stock rotors have an integral brake drum for the parking brake. Powerslot rotors are made with high quality dimensionally stable, wear resistant iron alloy with a high carbon and molybdenum content.  The rotor's friction surface is slotted to disperse vaporized brake pad material under hard braking.  The slots also help evacuate water making them work a little better in the wet.  The non friction surfaces of the rotors are e-coated for rust resistance.  The Powerslot rotors have radial vanes to pump air through the rotor helping it cool effectively.  The e-coating extends into the deepest parts of the rotors to prevent rusty water from dripping out. The Powerslot rotors are completely machined on all surfaces for better balance and dimensional accuracy.  The rotors are mill balanced to 2 ounce inches.  This makes for smoother operation and less NVH.  We also chose Powerslot's optional cryogenic treatment. Cryo treating is an extension of the heat treat process and converts the austenite in the iron to martensite greatly improving wear. 

To complement the brakes we went with Stoptech's braided steel brake lines and Street Performance brake pads.  The braided lines are teflon coated and resist expansion when pressure is applied.  By not ballooning under pressure, they make an improvement in brake pedal feel and firmness.  They also improve ABS operation. The street performance pads are semi metallic for better high temperature operation while being low noise, wear and dusting.

Technosquare's Howard Watanabe started our brake system install by removing the stock parts.
The Stoptech rotor dwarfs the stock Brembo part.  Amazingly the big rotor weighs 4 lbs less than the stock rotor!
We had to remove the factory dust shield to clear the bigger rotor.  In the front it was super easy, it just unbolted.


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