Brembo GT Rotors: Drilled, TY3, TY3L and TY5 Compared
Most Brembo GT brake systems use two-piece floating brake discs. The friction ring (rotor), made of high-carbon cast iron, is a wear part and can be replaced on its own, while the aluminium hat is reused. This page explains which rotor versions are available, how they differ and how to find the right replacement rotor using the part number.
- Drilled: quick response even in the wet, classic look – for street and sport driving.
- TY3L (slotted): the current street-legal version with the Brembo logo on the braking surface – successor to the TY1.
- TY3 (slotted): many short curved slots, maximum bite – for track days and racing.
- TY5 (slotted): fewer, longer slots, less wear – for endurance and long stints.
- TY1: straight slots, officially discontinued by Brembo and replaced by the TY3L.
- Part number: engraved on the outer edge of the friction ring.
Design: Why Two-Piece Floating Brake Discs?
A two-piece Brembo brake disc consists of three components:
- Friction ring (rotor) – high-carbon cast iron, internally vented (straight vanes, pillars or curved vanes).
- Hat (bell) – aluminium machined from billet.
- Bobbins (drive bushings) – connect ring and hat. They transmit the braking torque from the rotor to the hat and let the rotor expand radially when it heats up.
The advantages:
- Less weight where it matters most – the brake disc is both unsprung and rotating mass.
- No warping: the ring can expand independently of the hat, so it stays flat and true even under high thermal load.
- Better heat dissipation and higher fade resistance.
- Lower running costs: when worn, only the ring is replaced, not the complete disc.
All Brembo GT rotors have 10 mounting points. Each rotor needs a matching Brembo hardware pack (one pack per rotor).
Rotor Versions at a Glance
As of 2026: TY3L slotted and TY1 drilled are available, TY1 slotted is discontinued.
Drilled (TY1 Drilled)
 |
The classic choice for performance road cars. The holes carry gases, water and debris away from the braking surface and give a quick, even response even in the wet – combined with the typical high-end look. Best for: street, spirited driving, occasional track days. |
Slotted TY1 (Type 1) – no longer available
 |
The former standard slotted version with straight slots (listed in Brembo catalogues as "T1 x 8" – 8 slots per side). The slots clean the pad surface with every rotation. Status: officially discontinued by Brembo – the successor is the TY3L. |
Slotted TY3L – the TY1 Successor
 |
The current slotted version for the road. The curved Type 3 style slot pattern gives good initial bite and keeps the pad surface clean. You can recognise the TY3L by the Brembo logo on the braking surface. Best for: performance road cars – the TY3L is the street-legal version, not a track-only version. |
Slotted TY3 (Type 3)
 |
Many short, curved slots across the whole braking surface. The pattern comes from motorsport: it cleans the pads continuously and delivers a particularly aggressive bite, especially at high temperatures. Best for: intensive track days and racing, when maximum bite is needed. |
Slotted TY5 (Type 5)
 |
Fewer but longer curved slots. Compared with the TY3 the response is slightly smoother, while rotor and pad wear are lower. That is why the TY5 is popular in endurance racing. Best for: frequent track days and long stints, when durability matters more than maximum bite. |
The Differences at a Glance
| Version | Surface | Character | Use | Status |
|---|---|---|---|---|
| Drilled | cross-drilled holes | quick response, also in the wet | street / sport | available |
| TY1 | straight slots | cleans the pad | street / sport | discontinued → TY3L |
| TY3L | curved slots + Brembo logo | good bite, clean pad | street (street legal) | available |
| TY3 | many short curved slots | maximum bite | track / racing | available |
| TY5 | few long curved slots | less wear, high durability | track / endurance | available |
Where Is the Part Number on the Rotor?
The Brembo part number is engraved on the outer edge of the friction ring – on the narrow circumferential face between the cooling channels, not on the braking surface. Depending on the production year it is stamped or laser-engraved. You usually don't need to remove the disc to read it: take off the wheel, turn the rotor and shine a torch along the edge.
The part number (PN) is on the outer edge of the friction ring. |
Laser engraving on the outer edge: Brembo logo and lettering. The part number is engraved in this area too. |
Identifying the Version from the Kit Number
If you still have the part number of the complete Brembo GT system (e.g. 1G1.9017A2), the third character tells you the disc version:
- 1 = drilled, two-piece
- 2 = slotted, two-piece
- 4 = drilled, one-piece
- 5 = slotted, one-piece
The first character is the axle (1 = front, 2 = rear), the fourth and fifth characters are the disc size family (e.g. 60 = 318–330 mm, 80 = 343–356 mm, 90 = 357–404 mm).
Important Installation Notes
- Left and right: All slotted Brembo rotors are directional, regardless of the vane design. The slot edge closest to the outer diameter must meet the pad first. Rotors with curved vanes are directional as well. That's why every size comes as a left and a right rotor.
- Wear limit: The minimum thickness is 2 mm below the nominal disc thickness (e.g. 32 mm → 30 mm).
- Hardware: Replacement rotors are supplied without mounting hardware. Please order the matching hardware pack as well.
- Instructions: Brembo GT rotor replacement (PDF) and Brembo GT installation manual (PDF).
Frequently Asked Questions (FAQ)
Which is better: drilled or slotted Brembo rotors?
It depends on how you use the car. Drilled rotors respond quickly, even in the wet, and are the classic choice for the road. Slotted rotors clean the pads continuously and give more consistent braking at high temperatures – usually the better choice for frequent track days.
What is the difference between TY3 and TY3L?
Both have a curved Type 3 style slot pattern. The TY3L is the street-legal road version and carries the Brembo logo on the braking surface. The TY3 has many short slots across the whole surface and is designed for maximum bite on track.
What is the difference between TY3 and TY5?
The TY3 gives the more aggressive bite. The TY5 has fewer, longer slots and causes less rotor and pad wear, which makes it popular for endurance racing.
Is the TY1 rotor still available?
No. Brembo no longer officially offers the TY1 with straight slots. Its successor is the TY3L.
Can I swap drilled rotors for slotted ones?
Usually yes, as long as diameter, thickness and mounting are the same – the aluminium hat and the hardware pack stay the same. Check the part numbers in our rotor overview or ask us.
Where is the part number on a Brembo rotor?
On the outer edge of the friction ring, on the narrow circumferential face – stamped or laser-engraved. With the rotor fitted, it is usually easy to read once the wheel is off.
When does the rotor need replacing?
At the latest when it reaches minimum thickness (nominal thickness minus 2 mm), or if there are cracks running from the holes or slots or reaching the edge.
Does a replacement rotor come with mounting hardware?
No. Replacement rotors are supplied without hardware. Each rotor needs a matching Brembo hardware pack.
Which Rotor Is Right for You?
All sizes and part numbers – drilled and TY3L slotted, left and right, including the matching hardware packs – are listed in our Brembo GT discs and replacement rotors overview. Not sure? Contact our technical team – we're happy to help you choose.
