SY4030-SY4035
Front 4-piston caliper with monobloc bracket for mini cars
Specifications
SY4030/SY4035 — front 4-piston caliper with a monobloc body and an integrated mounting bracket for mini cars.
OVERVIEW
SY4030/SY4035 are in-house calipers with a one-piece (monobloc) body: the mounting bracket (bridge) is forged together with the body. This eliminates installation errors, simplifies fitting and increases rigidity. The body is forged from aluminium alloy: forging delivers high rigidity, tensile strength, toughness and material density. Compared with cast aluminium calipers, body rigidity is about 50% higher, which reduces the risk of caliper failure in service. The built-in double oil seal (instead of ordinary external dust boots) makes the brake feel and reaction more precise. After anodizing and vacuum coating (CVD) the colour is locked in: the coating does not crack or peel and gives the caliper a metallic sheen and vivid colour. The two versions differ in fitment size: SY4030 — W211 mm, SY4035 — W230 mm.
HIGHLIGHTS
• Monobloc body with an integrated bracket forged in one piece — simpler installation, no fitment errors, higher rigidity.
• Larger piston area — a more linear pedal feel.
• After multi-stage testing, performance is about 45% above the stock caliper.
• With high-performance pads it confidently handles intense driving — from mountain roads to the race track.
CALIPER SPECIFICATIONS
• Weight: SY4030 — 3200 g/pc; SY4035 — 3200 g/pc
• Piston area: 45.49 cm²
• Piston diameter: 34 mm × 2 / 38 mm × 2
• Brake disc diameter: Ø190 mm–Ø260 mm
• Brake disc thickness: max 10 mm
• Caliper dimensions: SY4030 — W211 × D111.4 × H60.5 mm; SY4035 — W230 × D111.4 × H60.5 mm
• Distance from mounting plane to the top of the disc: 45.71 mm
BRAKE DISC
• Friction surface width: 54.5 mm
• Ventilation: Ø380 × 34/26 — 84 curved ducts, 7 slots, PCD 258 mm; Ø355 × 32/26 — 72 curved ducts, 7 slots, PCD 233 mm; Ø332 × 32/26 — 72 curved ducts, 6 slots, PCD 210 mm
• Heat treatment: 580 °C heating / 120 °C cooling, cycled for 72 h
• Mounting hole diameter: Ø8.1 mm
• Centring ring: Ø209 mm (for 355×32 disc); Ø190 mm (for 332×32 disc), petal step 2.5 mm
• Surface treatment: iron phosphating, ground friction surface
• Disc standard: GG20HC
BRAKE PADS
• Model: S66B
• Thickness: 14 mm
• Friction surface width: 50 mm
• Friction block area: 67.31 cm²
• Compound: F500 (standard) / F600 (street, optional) / S750 (street & track, optional) / R900 (track, optional) / S800 (for carbon-ceramic discs, optional)
QUALITY CONTROL
• Forged body tensile strength: Qb ≥ 320 MPa
• Body hardness: HV ≥ 400
• Low-pressure seal test: 0.4 MPa air, hold 5 s, pressure drop ≤ 100 Pa
• High-pressure seal test: 12 MPa air, hold 5 s, pressure drop ≤ 0.2 MPa
• Appearance: anodized surface free of damage, uniform colour and gloss
• Ultra-high pressure test: sampled calipers withstand 30 MPa oil pressure without failure
• Other characteristics per QC/T592.