Koyo (Koyorad) Performance Radiator: Toyota GR Supra A90 / BMW Z4 G29 B58 2018+

Koyo Performance Radiator – Toyota GR Supra A90 / BMW Z4 G29 B58 2018+

Application: Toyota GR Supra (DB41/DB42) & BMW Z4 (G29) | B58B30C / B58 3.0L Turbo Inline-6 Petrol RWD

Part Number: HH423660 / KH423660

The A90 GR Supra is the return of an icon — and with the BMW-sourced B58 inline-six under the bonnet, it's a genuinely capable platform straight from the factory. But the B58 is also one of the most popular engines to tune right now, and as power levels climb, so does the demand on the cooling system.

Koyorad's all-aluminium radiator is a direct bolt-in performance upgrade for both the A90 GR Supra and the BMW Z4 G29, engineered to the same factory fit and mounting points as the OE unit. Nocolok furnace brazed, precision TIG welded by hand, and triple pressure tested — it retains all OEM connections with no modifications required.

Why Koyorad?

• Precise Tube & Fin Alignment — Strict quality control ensures optimal coolant flow and maximum heat transfer efficiency across the entire core.
• Nocolok Furnace Brazing — All tubes, fins, headers, and brackets are bonded in a state-of-the-art Nocolok furnace, creating a structure that resists vibration, road debris, and the elements.
• Billet Filler Neck — Precision-machined billet filler necks are fitted to every unit for superior strength, durability, and a reliable seal.
• OE-Specific Mounting — Application-specific mounting points ensure a pain-free, no-modification install.
• Hand-Crafted Heliarc Welds — Each radiator is individually Heliarc welded by hand, creating the strongest possible aluminium-to-aluminium bond across all components.

Specifications

• Part Number: HH423660 / KH423660
• Core Thickness: 48mm
• Core Dimensions (H × W): 175 × 231/247mm
• Tube Pitch: 64/64 × 249mm
• Overall Width: 186mm
• Construction: All Aluminium, Nocolok Brazed, Heliarc Welded
• Fan Shroud: Retains OEM mounts
• Fitment: Direct bolt-in, no modifications required

Cross Reference

• Koyorad: HH423660 / KH423660
• Toyota / BMW OEM: 16400 WAA04 / 17118672237

Fitment

• Year · Make · Model · Chassis · Submodel
• 2018+ · BMW · Z4 · G29 (2D Roadster) · M40i – B58B30C 3.0L Turbo Inline-6 Petrol RWD (250kW)
• 2018–2020 · Toyota · GR Supra · DB41/DB42 (2D Coupe) · GTS – B58 3.0L Turbo Inline-6 Petrol RWD (250kW)

Sold individually. Lead times may apply — contact us for availability and shipping estimates.