17Z brake caliper installed on BMW E90 M3

The Ultimate Budget Big Brake Kit for BMW E46 & E90 M3 (17Z / 18Z Setup Explained)

🏁 Intro

When it comes to upgrading your braking system, most BMW owners assume you need to spend $3,000 or more for a serious big brake kit. But there's a proven alternative that delivers OEM-quality performance, custom style, and bolt-on simplicity; all for a fraction of the price.

Meet the 17Z and 18Z big brake kit conversion. It’s one of the most popular and cost-effective brake upgrades available for the BMW E46 and E9X M3 platforms.

In this post, we’ll break down why it works so well, what’s included, and how you can build one to spec.

🔍 What is the 17Z / 18Z Big Brake Kit?

The 17Z and 18Z calipers are OEM Brembo units originally found on high-performance Audi and Porsche SUVs. These aren’t budget knockoffs, they’re genuine Brembo 6-piston front calipers with serious stopping power and long-term reliability.

  • 17Z calipers typically use 330–360mm rotors
  • 18Z calipers work best with 355–380mm rotors
  • Both pair well with 18–19" wheels depending on your barrel clearance

With the right brackets and hardware, they can be adapted to BMW platforms like the E46 and E9X with no modifications required.

⚙️ Why BMW Owners Love This Setup

1. Performance Without the Premium Price

You’re getting a full front and rear Brembo setup. 6-piston fronts, 4-piston rears, high-quality rotors, pads, and lines for less than half the price of most aftermarket kits.

2. Total Customization

At PRSTG, we let you build your kit to match your needs. You can spec your caliper color, rotor type, rotor size, and more to fit your build the way you want it.

3. Bolt-On Fitment

No guessing, no fabrication. Each kit is designed to work with your chassis, using CNC brackets and hub-centric rotors to ensure a direct bolt-on install. Pedal feel stays tight, ABS works normally, and nothing is compromised.

📦 What's Included in the Kit

Every PRSTG kit includes the essentials; nothing skipped, nothing pieced together. Here's what you get:

  • Refurbished OEM 17Z or 18Z Brembo calipers (rebuilt, refinished, and performance-ready)
  • OEM Brembo pads
  • Two-piece hub-centric rotors
  • Braided stainless steel brake lines
  • CNC-machined caliper brackets custom-made to your platform

This isn’t just a parts list. It's a complete system designed to perform as one.

🤔 17Z vs 18Z — What’s the Difference?

17Z 18Z
Caliper Size Compact Larger profile
Rotor Range 330–350mm 355–370mm
Wheel Clearance More flexible Usually needs 18"+
Ideal Use Street / mixed builds Aggressive / track-focused builds

Not sure what fits your wheels? Reach out and we’ll help you dial it in.

🛠 Built to Order by Enthusiasts

Every kit is made to order with an average turnaround of 8 to 10 weeks. That means your calipers, brackets, rotors, and pads are spec’d and built for your car, not pulled from a shelf.

Ready to get started? Build your custom kit here

Back to blog