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