SKU: 45292403332

Girodisc Rear 2-Piece Floating Rotor Set - F8x M2, M3, M4 W/ Blue Calipers

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Description

Girodisc Rear 2-Piece Floating Rotor Set - F8x M2, M3, M4 W/ Blue CalipersGirodisc is a Braking Technology Company dedicated to developing the best quality high performance braking components and solutions. The company has been in business since 2003 and is guided under the direction of company Principal Martin Meade, who spent five years as an Engineer with Porsche Engineering Services, where he played a role in developing current Porsche technology. PRODUCT INFORMATION The Girodisc system is a direct replacement for the

Girodisc is a Braking Technology Company dedicated to developing the best quality high performance braking components and solutions. The company has been in business since 2003 and is guided under the direction of company Principal Martin Meade, who spent five years as an Engineer with Porsche Engineering Services, where he played a role in developing current Porsche technology.

PRODUCT INFORMATION

The Girodisc system is a direct replacement for the OE disc. No modifications are necessary. The disc will bolt directly to the car and work with OE calipers perfectly. By upgrading your brakes with lightweight high performance replacements as opposed to a big brake kit, your factory bias is maintained as well as your ABS efficiency.

The central hat section of the Girodisc rotor is made from strictly U.S. sourced 6061-T6 aircraft specification aluminum.  The disc is made from Girodisc's own proprietary cast iron, poured in the USA and machined from start to finish in house at Girodisc.  The rotor utilizes a curved vane design, developed in racing to act as a centrifugal pump to force cooling air through the disc.

The rotor and hat have a floating mount system, which utilizes 10 high strength alloy steel drive pins, manufactured by Girodisc in the USA to their own specifications and cadmium plated for a long lasting corrosion resistance. These pins take the load from braking actions while maintaining the axial and radial float between the hat and disc. The pins are secured by class 12.9 cap screws with hardened washers. In order to keep the rotors from making noise when cold, the pins are mounted with anti-noise spring washers on the rotor side which allow the rotor to grow with heat expansion but eliminate the rattle and noise associated with floating rotors. This float also allows the rotor to self center between the pads.

Once the Girodisc system is in place, simply replace the cast iron rotor when needed.

Sold/priced per pair.


Fitment Information


This application is only for F87 M2 & M2 Competition Coupe, F80 M3 Sedan, F82 M4 Coupe and F83 M4 Convertible models, including Competition, CS and GTS, equipped with blue calipers and iron rotors. Not suitable for models fitted with silver/red M-Sport brake package (S2NH) or M Carbon Ceramic brake package (S2NK).

Girodisc Rotor Construction


The primary purpose of the Girodisc system is to reduce unsprung and overall vehicle weight. The secondary purpose is to increase the ventilation and cooling capacity of the brake disc while retaining it's original dimensions. This is accomplished by using two-piece disc construction. The central “hat” section of the disc is made from 6061-T6 aircraft specification aluminum.

The disc is made from cast iron, to the same specification and material as used by professional racing organizations. It is a curved vane design, developed in racing to act as a centrifugal pump to force cooling air through the disc. The rotor and hat have a floating mount system, which utilizes  high strength alloy steel drive pins, manufactured by Girodisc to our own specifications and cadmium plated for a long lasting corrosion resistance. These pins take the load from braking actions while maintaining the axial and radial float between the hat and disc. The pins are secured by grade 12 cap screws with hardened washers. In order to keep the rotors from making noise when cold, the pins are mounted with anti-noise spring clips on the rotor side which allow the rotor to grow with heat expansion but eliminate the rattle and noise associated with floating rotors. This float also allows the rotor to self center between the pads.


Important Questions Answered


What is required to install the Girodisc system?

The Girodisc system is a direct replacement for the OE disc. No modifications are necessary. The disc will bolt directly to the car and work with OE calipers and pads perfectly. Once the Girodisc system is in place, simply replace the cast iron rotor when needed. Some discs are larger in diameter and come with caliper spacers. If longer bolts are required, they are also supplied.

How does reducing weight of the braking system benefit the vehicle?

The Girodisc will generally weigh between 4 – 8 lbs less than the oe disc it will replace. This is due to the heavy cast iron hat section being replaced with lightweight, high strength aluminum. The mass of any vehicle requires energy to accelerate or decelerate. Reducing the vehicle mass improves acceleration, and requires less energy to be dissipated during deceleration. Rotating mass requires additional energy in order to increase or decrease its speed of rotation. Decreasing the mass of the disc has a great benefit due to reduction in rotational inertia. This will allow more of the braking force to be available to decelerate the vehicle, not the disc.

Additionally, the mass of the brake system is also unsprung mass. Reducing the unsprung mass has the additional benefit of improved suspension performance, resulting in enhanced ride and handling. Rotating masses require additional energy to vary the plane on which they turn. The lighter the disc, the quicker the response of the vehicle steering due to the reduction in gyroscopic effect/rotational inertia of the disc. As an example, compare the weight of the Ferrari 360 OE disc at 18.2 lbs, and the Girodisc at 14 lbs. The Girodisc is 4.2 lbs lighter per disc. Replacing all four discs will save 16.8 lbs of rotating, unsprung mass.

Why slotted discs?

The edges of the slots continuously clean and refresh the pad surface. This will allow the pads to have a maximized friction surface always available. Additionally, they prevent containments from collecting between the pad and disc interface. The disc is lightened, decreasing its rotational inertia. Slots prevent the formation of a water film on the disc in wet weather, maintaining the best brake response.

A note on drilled discs

Girodisc does not recommend drilled discsfor high performance applications. The rapid heating and cooling cycles will cause cracking on the friction surface of a drilled disc. The use of high friction or racing pads will exaggerate this condition. Most pad manufacturers specifically recommend that their race pads not be used on a drilled disc for this reason. Girodisc can drill discs for an additional fee,  if the customer is aware of the potential hazards of drilling the discs.

Note as example the cracking in this OE Ferrari 550 drilled disc after one track day. Also note this custom front disc of a Porsche 993 Turbo after hard use (see photos).


Please see photos attached


Should new discs and pads be bedded in and if so, how?

The answer is yes, for optimum performance, any time different friction materials or discs are introduced, a bedding procedure should be carried out.

Which direction should the discs rotate?

For maximum airflow and superior cooling, the Girodisc system uses curved vanes. For a curved vane internally vented disc, the geometry of the vanes dictates the direction of rotation. A curved vane disc must be installed with the vanes running back from the inside to outside diameters in the direction of rotation. Your discs will come with labels indicating their correct placement on the vehicle. Orienting the disc in this manner creates a centrifugal pump. The rotation of the disc causes air to be pumped from the center of the disc, through the vanes, and out through the outside diameter of the disc. This greatly enhances the disc’s ability to dissipate heat. Discs installed backwards have very limited cooling.

Models
  • 2 Series / F87 M2 (2016-2021) / M2 Competition
  • 2 Series / F87 M2 (2016-2021) / M2
  • 2 Series / F87 M2 (2016-2021) / M2 CS
  • 3 Series / F80 M3 (2014-2019) / M3
  • 3 Series / F80 M3 (2014-2019) / M3 Competition
  • 3 Series / F80 M3 (2014-2019) / M3 CS
  • 4 Series / F82 / F83 (2014-2019) / M4
  • 4 Series / F82 / F83 (2014-2019) / M4 Competition
  • 4 Series / F82 / F83 (2014-2019) / M4 CS
  • 4 Series / F82 / F83 (2014-2019) / M4 GTS


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        Exchange/Return Notes
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        SKU: 45292403332

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        Robin
        Carnegie, US
        ★★★★★ 4
        Fast paced romantasy you will not want to put down!
        Format: Kindle
        4.25 stars! I LOVED this book with similar vibes to Hush Hush, Fourth Wing, and The Serpent and the Wings of Night! It was fast paced with easy world building and will keep you turning the pages late into the night because you will not want to put it down! Huntyr is a fierce bad@ss FMC trained to kill vampyres her entire life. She is sent on a mission to go to the academy and earn her spot into The Golden City. Upon arrival, she is forced to room with the delicious fallen angel, Wolf, who is the only one who knows about her assassin identity. The romance, the plot twists, the secrets revealed, the battles, and the tantalizing training scenes had me hooked! And that ending…. I’m holding my breath in need to know hell! Read if you love: 🪽 Fae, Vampyres, Fallen Angels 🪽 Academy setting with magical trials 🪽 Forced proximity and slow burn 🪽 Rivals to lovers 🪽 Hidden identities and secrets 🪽 Tend your wounds “𝘖𝘧 𝘤𝘰𝘶𝘳𝘴𝘦 𝘐 𝘸𝘢𝘴 𝘸𝘢𝘵𝘤𝘩𝘪𝘯𝘨 𝘺𝘰𝘶. 𝘐 𝘤𝘰𝘶𝘭𝘥𝘯’𝘵 𝘭𝘰𝘰𝘬 𝘢𝘸𝘢𝘺 𝘧𝘰𝘳 𝘢 𝘮𝘰𝘮𝘦𝘯𝘵, 𝘦𝘷𝘦𝘯 𝘪𝘧 𝘐 𝘵𝘳𝘪𝘦𝘥.” “𝘐𝘧 𝘺𝘰𝘶 𝘸𝘢𝘯𝘵 𝘮𝘦 𝘰𝘯 𝘮𝘺 𝘬𝘯𝘦𝘦𝘴, 𝘏𝘶𝘯𝘵𝘳𝘦𝘴𝘴, 𝘢𝘭𝘭 𝘺𝘰𝘶 𝘩𝘢𝘷𝘦 𝘵𝘰 𝘥𝘰 𝘪𝘴 𝘢𝘴𝘬.” “𝘠𝘰𝘶 𝘥𝘰 𝘯𝘰𝘵 𝘬𝘯𝘰𝘸 𝘵𝘩𝘦 𝘷𝘪𝘰𝘭𝘦𝘯𝘤𝘦 𝘵𝘩𝘢𝘵 𝘳𝘶𝘯𝘴 𝘵𝘩𝘳𝘰𝘶𝘨𝘩 𝘮𝘺 𝘷𝘦𝘪𝘯𝘴, 𝘣𝘦𝘨𝘨𝘪𝘯𝘨 𝘮𝘦 𝘵𝘰 𝘰𝘣𝘭𝘪𝘵𝘦𝘳𝘢𝘵𝘦 𝘢𝘯𝘺𝘰𝘯𝘦 𝘸𝘩𝘰 𝘭𝘢𝘺𝘴 𝘢 𝘩𝘢𝘯𝘥 𝘰𝘯 𝘺𝘰𝘶.”
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        Reviewed in the United States on June 12, 2024
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        Excellent Rivals to Lovers!!
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        Reviewed in the United States on August 15, 2025
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        ❈ Elizabeth ❈ | Breakawayreads
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        ★★★★★ 5
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        Rating: 4.5 | Spice: 2 (but a good slow-burn) • Main Characters: Huntyr and Wolf • I couldn’t wait to read this book; there was so much hype about it! And there was no doubt why. I fell in love with the characters and the plot itself. This book is mainly plot driven more than friction driven but it’s easy to follow along with. The characters are fun, easily understood. The main setting is at an academy where both the main characters are going through trials and building strength for the final test, The Transcendent. There are fantastic side characters as well. I loved the camaraderie between Huntyr and her friends. But we don’t like Lanson. 😆 We do have some plot twists that come into play throughout the book. Secrets and betrayal to be seen. I did adore Wolf and Huntyr’s relationship. It was a classic slow burn trope. They didn’t hit it off fast, but in time their feelings grew. I loved their banter, so sexy. Wolf is your next book boyfriend; Huntyr is your next vampire assassin independent bad-a*s female. Themes include loyalty, trust, self-discovery, a true slow burn romance. Side note: book ends on a angsty cliffhanger! • Emily, thank you for writing this awesome novel and I cannot wait to devour Book 2, Blood So Brutal! 😍 • Happy reading, my lovelies! xo
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        Reviewed in the United States on January 21, 2024
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        MelsABookworm
        Draper, US
        ★★★★★ 4
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        3.5 🌟 This book popped up in my KU recommended reading suggestions and the synopsis sounded like what I was in the mood for. I'm so glad I took a chance on it. I went into this knowing absolutely nothing about it and ended up really liking it. I love when this happens. The main characters are likeable and I easily found myself rooting for them. There is a mystery element to each of their backstories that I enjoyed watching unfold and can't wait to get more of. Wolf, in particular, has me fixated. Love him. I found this to be an entertaining, addictive read with a plot that moves along at a good pace. It reads so easily I found myself very reluctant to put it down. Lots of twists and turns and the angst is there. A good set up for the next book to come, for sure. My issues with this book....the dialogue feels a bit juvenile at times and there is a repetitive over use of a particular word phrasing that I found myself giving the ole eye-roll to. There are, without a doubt, some pretty cliche moments that gave me a bit of the cringe. I think this could've certainly 100% benefited from more depth regarding the world building. Perhaps the world building was sacrificed to keep the pacing quick? Just a guess. Also, the lack of consistency of character for the FMC was really evident and so she feels quite illogical at times. Overall, this was a fun and enjoyable read that hit the spot well enough for me. That ending certainly has me impatiently pining for book 2!
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        Reviewed in the United States on June 18, 2024
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        Amazon Customer
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        Reviewed in the United States on May 12, 2024

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