V8R NA & NB Miata XRZ4R Brake Kit

As used on the Grassroots Motorsports LFX enduro race car

The original 11.750" big brake kit! We designed our own BBK after testing many others. We start with a 11.750" rotor for maximum thermal capacity under a 15" wheel and designed our own hats. CAD designed and FEA tested, our hats weigh just over 1lb and are designed with cooling reliefs and max offset for better wheel clearance. We machine our hats and brackets in house true run out and proper alignment with the OEM uprights. Our kits are direct bolt-on, unlike cheaper kits that require hub rings and alignment shims. Hats use a motorsports grade bolt through hardware kits and do not require safety wire.

What’s Included:

• Wilwood   XRZ4R Radial Mount – 20mm pad(10420)
• Rotor of your choice - fixed or floating - Floating rotor installation guide
• V8R billet 6061 caliper brackets with stainless steel helicoils & mounting hardware
• DOT approved stainless steel brake lines
• Type-III black hard coat anodized plated hats
• Can be upgraded to a four-wheel BBK using one of our rear kits

Calipers

XRZ4R Radial Mount - Wilwood’s next-generation XRZero race calipers combine decades of race experience, computer finite element analysis (FEA), and state-of-the-art machining into a race caliper that is lighter and stiffer, with zero drag. The unique shape of the high surface area body creates a caliper with superior brake fluid cooling and allows more airflow through the rotor. Optimized profile high-temperature seals provide better piston retraction resulting in less drag. The unique center X-bridge strengthens the caliper body without adding mass or obstructing airflow to the brake rotor or pads. Computer FEA design and precision CNC machining of the stress-flow forged aluminum body results in a caliper weighing just 4.66 pounds - 1/2 pound less than a comparable sized Wilwood Superlite caliper.

Rotors

Available with the standard Wilwood Ultralite32 straight vane or with upgraded V8R Directional or PFC slotted rotors. Floating kits are standard with V8R directional floating rotors.

Brake Pads

Our kits are sold without pads to allow the end-user to select the pad type that best suits their needs.. This kit uses the Brake Pad Plate # 10420 (20mm). That means there are already a huge amount of compatible brake pads for this kit. Pads are readily available for this brake kit from the following manufacturers:

• Hawk Performance
• Porterfield
• Stoptech
• Wilwood
• Performance Friction
• Ferodo
• Raybestos
• G-Loc
• Carbotech
• Cobalt

Wheel Fitment

This kit is HUGE! Most aftermarket 9" wheels will require a 5mm spacer. All 10" wheels that have fitted in house clear without a spacer. There are many different wheel options and we recommend checking your wheels with the template below before purchasing.

Design

All V8R parts are CAD designed, FEA tested, and machined in house using today’s latest CNC equipment. This kit has been tested extensively in the harshest conditions, both on the street and at the race track, to insure the absolute best performance.

Spare Parts

Like any kit destined for years of abuse, a ready supply of spare parts is incredibly important when considering whether or not to buy an aftermarket braking system. We took this into consideration when designing this kit, and as such are able to keep the price of consumables lower than almost any other brake kit on the market today. Rotor rings replacement start at $32, brake pads from as low as $48, and replacement hardware are all readily available through us, as well as many online vendors. Because this caliper uses a pad shape that has been in production for over two decades, and a rotor size and bolt pattern shared with many off-the-shelf brake solutions, parts will always be affordable and readily available.