StopTech 328mm Big Brake Kit - 4-Piston ST41 - Mk5 GTI / GLI, Mk6 GTI / GLI

StopTech Big Brake Kits improve aesthetics and exceed stock brake performance in three areas. First, larger rotors increase heat capacity. Second, improved brake cooling dissipates absorbed heat. Third, stiffer calipers and stainless steel lines reduce system compliance.

The key, however, is to increase heat capacity and reduce compliance without upsetting the stock front to rear brake torque ratio, also referred to as brake bias. Regardless of rotor diameter, brake pedal ratio, brake pad material, or number of pistons in your calipers, your maximum deceleration is limited every time by the tire to road interface. If the brake upgrade you select adds too much front brake torque (as many do), it will drastically shift the brake bias too far forward and reduce your car's ability to utilize the maximum traction of the tires at all four corners (even on ABS equipped cars), increasing stopping distances dramatically. In addition, too many pistons or pistons that are too large will make the brake pedal much more difficult to modulate, which limits a driver's control of brake input.

Advantages of the StopTech ST-41 Big Brake Kit over other brake upgrades:

• StopTech Balanced Brake Upgrades™ with optimum brake bias offer the shortest stopping distance with the best pedal feel
• StopTech offers the stiffest aftermarket calipers available, their patented bridge results in better clamping under hard braking and less pad taper
• StopTech Sport Rotors offer excellent airflow available which results in better cooling, less fade and longer rotor and pad life
• StopTech Stainless Steel Brake Lines are resistant to expansion which offers better brake modulation and a firmer brake pedal
• StopTech Brake pads combine the benefits of premium street brake pads with aggressive friction formulas suitable for track day and autocross use. 

StopTech ST-41 4 Piston Calipers

StopTech's ST-41 calipers are fully forged, this produces a beautifully finished solid part without porosity. StopTech does all finish machining (such as piston bores sized correctly for the application), assembly and test in California. Calipers that are cast can have major issues with porosity which can even cause calipers to leak. Dust boots are standard on StopTech calipers to keep the pistons clear of contamination and extend the service life of the calipers. Competitors calipers designed without dust boots require rebuilding every two years.

Advantages of StopTech's ST-41 4 Piston Calipers:

• Pistons sized to match brake kit to vehicle application
• ST-41 caliper uses standard FMSI D608 brake pad
• 100% leak down and pressure tested to 2,500 PSI
• Differential piston sizes minimize pad taper
• Made of forged aluminum alloy
• Weight: 7.94 lb (3.6 kg) unloaded
• Dust boots are standard 

StopTech's Patented Caliper Bridge

Using finite element analysis (FEA) modeling software, StopTech has designed a bolt-in bridge strong enough to stop distortion without sacrificing cooling through the top of the caliper. The air channel in the bridge helps air flow through the retainer, resulting in better cooling.

Advantages of Stiffer Calipers:

• Better performance with no vibration or noise
• No radial pad taper
• Better pedal feel 

StopTech Caliper Brackets

StopTech caliper brackets are machined from AeroSpace billet aluminum on the latest active tooling CNC machines at StopTech's California manufacturing facility.

StopTech's Sport Rotors

StopTech's Sport Rotors are cast at Pilenga S.p.A., the second largest rotor manufacturer in Europe. Pilenga is ISO9002 and Vision 2000 certified and has been casting brake rotors for over 50 years. StopTech developed a proprietary cast iron formula for the Rotors after extensive testing to ensure high durability under extreme use. The ability to absorb and dissipate heat is essential to brake system performance. The StopTechSport Rotor features uniquely designed curved vanes with innovations on leading and trailing edges to optimize airflow through the rotor. This improved directional design minimizes turbulence and flows more air than any rotor tested. The result is up to 80% better airflow over original equipment rotors and 10-30% better airflow than directional vaned racing rotors currently available.

Advantages of StopTech Sport Rotors:

• Enhanced durability for decreased lifetime costs
• Superior airflow for increased heat dissipation
• Consistent and predictable performance
• Extended rotor life
• Increased pad life
• Less fade 

StopTech Performance Street Brake Pads

StopTech makes their own stainless steel brake lines in California from the highest quality parts available. StopTech brake lines consist of a Teflon® inner line that is covered with a layer of stainless steel woven braid. The Teflon® tube is very resistant to expansion under pressure and will not degrade from exposure to brake fluid. The stainless steel braid provides support for the Teflon and the weave is extremely durable against incidental impact and abrasion. Lines feature a clear abrasion-resistant cover for maximum protection against chaffing and particle intrusion. Every fully assembled StopTech Stainless Steel Brake Line is tested to a pressure of 4,500 PSI. StopTech is a DOT (U.S. Department of Transportation) registered supplier of brake lines.

Advantages of StopTech Brake Pads:

• Wide operating temperature range improves stopping power hot or cold
• Consistent and predictable performance
• Excellent pad life
• Longer rotor life
• Reduced dust
• Low noise

Please download and print the correct wheel fitment template for your vehicle here. This template will allow you to see if your wheels will clear this brake kit properly. If you have any questions regarding fitment, please feel free to contact us.