Which cars use the GiroDisc 390x34mm Front Replacement Rings?

Bulletproof Automotive lists the GiroDisc 390x34mm Front Replacement Rings for the Alfa Romeo Giulia Quadrifoglio running GiroDisc 390mm front hats. GiroDisc names the part by size alone, so check that the hats on the car are GiroDisc 390x34mm before ordering.

Are hats included with the 390mm rings?

No. The set is two iron rings with replacement mounting hardware. The rings bolt to GiroDisc hats already on the car and are not designed for factory two-piece hats or hats from other brands, so a car needs GiroDisc hats in place first.

What do the dimensions 390x34mm mean?

The first figure is the outer diameter of the ring, 390mm, and the second is its thickness, 34mm. Both match the GiroDisc front hats these rings are made for. Replace the rings at the minimum thickness marked on the hat and the ring edge.

How are the 390mm rings cooled?

Each ring uses curved internal vanes that work as a centrifugal pump. As the wheel turns, air is drawn in near the hub and forced out through the disc, carrying heat away from the friction faces during repeated hard stops on track.

Do these rings differ from the D1-224 Quadrifoglio rings?

Yes. D1-224 is the GiroDisc ring set for its A1-224 Giulia and Stelvio Quadrifoglio front rotors, while these D1-163 rings are a 390x34mm size listed on their own. Match the ring to the hats on the car, and ask Bulletproof Automotive if unsure.

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Description

GiroDisc 390x34mm Front Replacement Rings for Alfa Romeo Giulia Quadrifoglio

GiroDisc’s 390x34mm Front Replacement Rings for Alfa Romeo Giulia Quadrifoglio cars are large-diameter iron rings for owners already running GiroDisc 390mm front hats on the twin-turbo sedan. They come as a pair with replacement hardware, cast from GiroDisc’s proprietary high-carbon iron, poured in the USA and machined in Bellingham, Washington. At 390mm across and 34mm thick, they suit a Quadrifoglio that sees regular track time, and the hats they bolt to are reused, not replaced.

Fitment and Installation

These rings bolt to GiroDisc hats only; they are not designed for factory two-piece hats or other brands. Unbolt the worn rings, fit the new pair with the supplied hardware and keep the cap screws at or below 60 in-lb, or 7 Nm, so the ring can float. Each ring is labeled for its side, and minimum thickness is marked on the ring edge.

Features

390mm outer diameter, 34mm thick, per GiroDisc
Sold as a left and right pair
Replacement mounting hardware included
Proprietary high-carbon iron poured in the USA
Curved internal vanes for cooling
Slotted friction face

What’s Included

Front replacement rings (L/R)
Replacement mounting hardware

Applications

Alfa Romeo Giulia Quadrifoglio: with GiroDisc 390x34mm front hats | 2.9L twin-turbo V6

Notes

The 390x34mm Front Replacement Rings fit GiroDisc hats only; hats are not included
GiroDisc lists these rings by size, so confirm your car carries GiroDisc 390x34mm front hats before ordering
For cars on GiroDisc A1-224 front rotors, the GiroDisc Giulia and Stelvio Quadrifoglio front replacement rings are the matching set
Replace the rings at the marked minimum thickness or if a crack reaches the edge
Stock photography may not depict the actual product

Frequently Asked Questions

Which cars use the GiroDisc 390x34mm Front Replacement Rings? Bulletproof Automotive lists the GiroDisc 390x34mm Front Replacement Rings for the Alfa Romeo Giulia Quadrifoglio running GiroDisc 390mm front hats. GiroDisc names the part by size alone, so check that the hats on the car are GiroDisc 390x34mm before ordering.
Are hats included with the 390mm rings? No. The set is two iron rings with replacement mounting hardware. The rings bolt to GiroDisc hats already on the car and are not designed for factory two-piece hats or hats from other brands, so a car needs GiroDisc hats in place first.
What do the dimensions 390x34mm mean? The first figure is the outer diameter of the ring, 390mm, and the second is its thickness, 34mm. Both match the GiroDisc front hats these rings are made for. Replace the rings at the minimum thickness marked on the hat and the ring edge.
How are the 390mm rings cooled? Each ring uses curved internal vanes that work as a centrifugal pump. As the wheel turns, air is drawn in near the hub and forced out through the disc, carrying heat away from the friction faces during repeated hard stops on track.
Do these rings differ from the D1-224 Quadrifoglio rings? Yes. D1-224 is the GiroDisc ring set for its A1-224 Giulia and Stelvio Quadrifoglio front rotors, while these D1-163 rings are a 390x34mm size listed on their own. Match the ring to the hats on the car, and ask Bulletproof Automotive if unsure.

About GiroDisc

GiroDisc designs, manufactures, and sells 2-piece, fully floating brake rotors for a wide range of performance vehicles. Every major component, including the hats, rotor rings, and drive pins, is manufactured in-house at their facility in Bellingham, Washington, from domestically sourced materials. GiroDisc rotors use a proprietary high-carbon iron ring formulated for superior metallurgy and thermal performance, paired with reusable machined-aluminum hats that reduce the long-term cost of maintaining a high-performance brake system. The 2-piece floating design sheds unsprung and rotating mass while remaining street-friendly, delivering race-proven braking for track and street use alike.

Additional Information

The Bulletproof Automotive website contains many thousands of products purchased in multiple different currencies. All of the prices are entered manually and accurately at the time of entry. Due to the consistently fluctuating international exchange rates, at times prices may not be able to be honored at their original intended rate. We apologize for any inconvenience this may cause, unfortunately our website is unable to compensate dynamically for what can at times be volatile changes in the cost of items due to currency values fluctuating, changes in prices from suppliers, changes in shipping and import duties, and other factors. Rest assured that any order you place on line will be at zero risk to you in this area. If in the event your order cannot be fulfilled at the original intended website price we will offer you a 100% refund, no questions asked. We will continue to do our best to maintain updated prices and we will always continue to offer our price match guarantees as well to ensure our prices are always the best for you. In short, prices may change without notice. It is always advised to give us a call prior to placing your order online to confirm availability and to confirm current pricing.

Shipping Policy

Items that are in stock in the US, either at Bulletproof’s warehouse or at a supplier’s warehouse, are generally delivered within 7-10 days. Special order items from overseas take considerably longer. As a courtesy Bulletproof offers delivery estimates to our customers which take into consideration manufacturer availability and shipping schedule. These estimates represent our best guess based on previous orders from the manufacturer and do not in any way imply a guaranteed delivery window. Many manufacturers work in a “just in time” inventory system and often take 2-20+ weeks to produce an item once an order is submitted. All deliverable items are then sent to our Japanese warehouse. Bulletproof ships a minimum of one full ocean freight container every month from Japan, oftentimes more than one a month. Ocean freight takes an average of 4 weeks. Typically it breaks down to one week in Japan for paperwork and customs, two weeks by boat and one week in US customs/clearance. Due to the wide number of variables between manufacturer and shipping schedules, delivery estimates are simply just that – estimates. We attempt to estimate conservatively and we usually deliver faster than our estimates suggest. It is not Bulletproof’s policy to guarantee delivery time of any special order item, this is impossible for us to do. By ordering you acknowledge that there is no required delivery ETA and an order may not be canceled or altered due to manufacturing or shipping delays, all ETA’s are provided as a best guess only. Please review the full Terms & Conditions here.

BP Pricing Difference

We do pricing a little differently on our JDM brands and we believe in making things simple and clear. No hidden fees or surcharges. Every price you see includes the shipping cost to our office in Los Angeles, California and all the associated taxes/duties/fees for bringing the products into the US. The only shipping you ever pay is from our facility in the US to your location. Be wary of resellers that don’t include the cost of international shipping in their pricing on JDM parts. While we believe we’ll always have the lowest all-in price on JDM products, we offer a price match guarantee for all authentic parts purchased from authorized dealers as well. For many international customers, it’s much more affordable to ship from the USA than from Japan directly, as the air freight and ocean freight costs are typically much less. However, for customers looking to ship directly from Japan outside of North America, or domestically in Japan, we can provide pricing specifically for that scenario. Please do not hesitate to contact us with any pricing questions or concerns. Please email us at sales@bulletproofautomotive.com with any inquiries.

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GiroDisc 390x34mm Front Replacement Rings for Alfa Romeo Giulia Quadrifoglio [D1-163]

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GiroDisc 390x34mm Front Replacement Rings for Alfa Romeo Giulia Quadrifoglio

Fitment and Installation

Features

What’s Included

Applications

Notes

Frequently Asked Questions

About GiroDisc

Reviews