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Big Brake Kit

XYZ Racing Hollow Front Brake Kit — Audi S4 C4 (HUB M14) (1991-1994)

SKU: XYZ-BRK-BKF-AU-21-A-FRONT

  • IncludesFront axle pair (2 discs + 2 calipers)
  • PositionFront
  • Disc Ø330–444 mm
  • Caliper pots6 / 8 / 12-pot
  • Lead time10–15 working days

Fits Audi S4 C4 (HUB M14) (1991-1994)

Brake pad compound

Street: quiet, low-dust, strong cold bite for road driving. Sport: higher temperature range and more bite for fast road and occasional track. Racing: maximum fade resistance for sustained track use (noisier and dustier cold). Match the pad to how hard you actually brake.

Disc size

Caliper grade

Hollow is the standard caliper: a lighter hollow-body forged caliper with a dust cover and a 5-year warranty. Hollow Racing drops the dust cover for sustained high-temperature use (rated to 1000°C, 2-year warranty) — the track-grade choice.

Caliper colour

Painted colours are included. Polished-forged finishes are mirror-polished forged calipers (Titanium, Gold, Silver); candy colours are a deep, mirror-reflection paint. Both are premium upgrades — fuller detail further down the page.

Painted — includedTell us the exact Pantone (PMS) code you want the calipers painted.Polished forgedCandy
Disc style

Drilled discs (cross-drilled holes) vent gas and water and look aggressive; slotted discs (surface grooves) wipe the pad face clean and resist fade under sustained hard use. Same price — choose on looks or how you drive.

Centre bell

The centre bell is the CNC-machined aluminium hat that joins the disc to the hub. Standard anodized is included; a two-tone bell adds an anodized accent ring in your choice of colour; titanium is the lightest, forged option.

Carbon-ceramic rotor

Carbon-ceramic rotors are a special-order track upgrade: far lighter than steel, fade-resistant at extreme temperatures and extremely long-lived. The price follows the disc size you choose above. The standard two-piece steel rotor is included.

Configured price£2,000.00Inc. VAT

Lead time: 10–15 working days from payment


£2,000.00

Made to order. Full payment is taken at checkout. Production begins once payment is confirmed.

Pay by card, Apple Pay, Google Pay — or Klarna on eligible orders.

Caliper render for this kit:

XYZ Racing Hollow Front Brake Kit — Audi S4 C4 (HUB M14) (1991-1994) — 330 mm
330 mm

The C4-generation S4 was always an exercise in contained aggression: a 2.2-litre turbocharged five-cylinder, over 1,600 kg of car, and a quattro system that disguised how quickly the speed was building. Original front brakes were adequate by early-1990s touring standards; by any modern track day benchmark, they are the weak link. Under repeated hard braking from three-figure speeds, fade sets in, and the nose-heavy quattro balance means the front axle takes a disproportionate share of the deceleration load every time.

This XYZ Racing front big brake kit is built for exactly that scenario on the 1991-1994 S4 C4 with M14 hub fitment. It fits as a matched pair of front calipers and two-piece floating discs across the front axle, with three pad compounds to match the kit to how the car is driven, from spirited road use through to sustained circuit sessions.

What this brake kit does for your 1991-1994 Audi S4 C4 (HUB M14)

Upgrading the front axle hardware addresses the C4 S4’s most persistent dynamic weak point. The larger rotor swept area and increased caliper clamping force reduce the heat accumulation that erodes confidence in repeated braking zones, extending the point at which fade compromises the car’s behaviour. The hollow-vane discs move heat out of the friction surface faster than the original solid rotors, the two-piece floating construction lets the disc grow with temperature without warping the bell, and the lighter assembly trims rotating and unsprung mass off the front corners. Braided lines come as part of the kit to firm up the pedal.

Three pad compounds tune the kit to use. Street is the quiet, low-dust default that holds consistent bite in the wet and cold of UK fast-road driving, relevant for a platform many owners run year-round. Sport adds bite and heat range for harder road and mixed road-and-track use. Racing sustains stopping power deep into a circuit session, well beyond where the original brakes began to fade. Included painted caliper colours are Red, Yellow, Gold, Black and Anodized Black at no extra cost.

About the front brake kit

This is XYZ Racing’s front big brake upgrade, supplied as a complete front-axle package with its own discs, calipers, and fitting hardware. The calipers are hollow-bodied as standard for strength without excess weight, with an optional Hollow Racing upgrade for committed circuit sessions where thermal endurance under repeated hard braking is the priority, dropping the dust cover, rated to 1000C and carrying a two-year warranty. The M14 hub configuration is specific to the C4 S4’s fitment profile and is not interchangeable with later Audi generations that carried different hub stud specifications.

Pad compound is chosen at order. Beyond the included painted finishes, a Custom Color in any Pantone is available, along with premium polished-forged Titanium, Polished Gold and Polished Silver and candy Teal, Blue, Red and Orange. Discs come drilled or slotted at the same price, and centre-bell upgrades, two-tone in five anodized colours or in titanium, are selectable at checkout. For a platform now approaching its mid-thirties, the complete-kit format removes the need to source and match components separately; discs, calipers, and hardware arrive together, ready to fit.

Fitment for the Audi S4 C4 (HUB M14) (1991-1994)

This kit is confirmed for the Audi S4 on the C4 platform, covering 1991 to 1994 in M14 hub specification. Verify that your car carries M14 hub studs before ordering; C4-series Audi models were produced with different hub configurations, and this kit is matched to the M14 variant specifically.

What buyers also search for

  • Audi S4 C4 front brake upgrade for track day and fast-road driving
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  • Audi S4 C4 front brake fade fix for sustained high-speed use
  • C4 S4 front caliper upgrade in multiple finishes including custom Pantone

Confirm your hub specification and choose your compound and caliper finish from the options above, and we build it to your spec.

What’s in the kit

Front axle kit — supplied as a complete bolt-on assembly.

  • 2×Two-piece floating discs — 330–444 mm: you pick the exact diameter with the "Disc size" option
  • 2×Lightweight aluminium centre bells
  • 2×Forged aluminium calipers — 6 / 8 / 12-pot
  • 2×High-stiffness mounting brackets
  • 2×Braided stainless steel brake lines
  • 4×High-performance brake pads (1 set)
  • 1×Fitting hardware & tools pack

Choosing your spec

Every kit is built to order around the choices you make above. Here is what each option actually changes, so you can spec yours with confidence.

Brake pads — Street, Sport or Racing

Every kit ships with a full set of high-performance pads; the compound is your call.

Street is the right default for fast-road driving — a strong, progressive cold bite with low noise, low dust and long disc life. Sport raises the working temperature and adds bite and fade resistance for hard road use and the occasional track day, while still behaving on a cold morning. Racing is a track compound built for sustained abuse: huge fade resistance and bite once heat is in it, at the cost of more noise and dust when cold. Match the pad to how hard you actually use the brakes — there is no benefit to a race pad that never gets up to temperature.

Caliper grade — Hollow vs Hollow Racing

Hollow is the standard caliper on every kit: a hollow-body forged caliper, lighter than a solid one, fitted with a dust cover and backed by a 5-year oil-leak warranty. For most fast-road and spirited track use it is all the caliper you need.

Hollow Racing is the track-grade upgrade. It runs the same hollow body but without a dust cover (so there is nothing to melt at sustained high temperature), uses a twin-metal piston that isolates heat travelling from the disc to the oil seal, and is rated to 1000°C. Available 286–380mm (front). Warranty is 2 years on oil leaks and 10 years on appearance. Built for professional racing and repeated track days.

Hollow Racing caliper

Caliper colour & finish

Painted colours (Red, Yellow, Gold, Black, Anodized Black) are included at no cost. Want an exact match to your car? Custom Color (+£150) paints the calipers to any Pantone code you supply (15–20 day lead time).

Polished Forged finishes are the flagship: a forged caliper given a mirror-polished surface treatment that shifts colour with the viewing angle. Beyond the looks, the polished surface dissipates heat better, resists rust and stands up to the weather. Choose Titanium (neochrome, +£350), Polished Gold (+£300) or Polished Silver (+£250). They look their best paired with a titanium centre bell. Care: clean only with a dilute neutral cleaner or water.

Candy colours (+£200) use a deep candy-paint and polishing process for a mirror-reflection, boutique finish — pick Teal, Blue, Red or Orange (shown below right).

Polished forged caliper finishes
Candy caliper colours

Centre bells

The centre bell is the CNC-machined aluminium hat that joins the disc to the hub. The standard anodized centre bell is included. The Two-tone bell (+£200) adds an anodized accent ring — choose Red, Yellow, Orange, Purple or Silver right here at checkout. The Titanium centre bell (+£500) is a forged titanium bell (bolts not included) that finishes off the polished-forged look.

Two-tone anodized centre bells
Same car

Other products that fit this vehicle

Front & rear brake kits, coilovers and more for this car

  • More XYZ products for the Audi S4 C4 (HUB M14) appear here as the rest of the range publishes.