Supertech B58 Conical Valve Spring Kit with Titanium Retainers – BMW M340i, 540i, 440i, Z4 M40i and Toyota A90 GR Supra – Part No. SPRK-B58B
Upgrade your B58 valvetrain with the Supertech Conical Valve Spring Kit SPRK-B58B. Engineered for the BMW and Toyota B58 platform, this conical dual spring and titanium retainer package delivers rock-solid valve control at high RPM, outstanding durability and proven reliability for tuned road and track cars. We run this Supertech kit on our own B58 builds and customer cars, and feedback has been consistently excellent.
Made from Supertech’s premium Superclean Chrome Silicon Vanadium Steel Alloy and paired with CNC machined, military certified titanium retainers, this kit is designed to maintain valve control, reduce the risk of valve float and improve valvetrain stability under sustained high load. Computer-optimised wire stress keeps the springs operating safely within limits for long-term durability.
Why choose Supertech valve springs for your B58
- B58 valve spring upgrade for high RPM stability and reduced valve float
- Conical dual spring design for superior control and harmonics management
- Titanium retainers reduce valvetrain mass for sharper response
- Superclean Chrome Silicon Vanadium steel for strength and longevity
- Computer designed to keep wire stress within safe limits
- Ideal for performance tuning on BMW M340i, 540i, 440i, Z4 M40i and Toyota GR Supra A90
Specifications
- Type: Conical Valve Spring
- Coil bind: 27.00 mm
- Max net lift: 12.20 mm
- Outer spring outer diameter: 26.50 mm
- Outer spring inner diameter: 18.70 mm
- Inner spring outer diameter: 21.60 mm
- Inner spring inner diameter: 13.80 mm
- Rate: 10.30 lbs/mm
- Open pressure: 180 lbs at 10 mm
- Seat pressure: 77 lbs at 40.10 mm
What’s included
- 24 dual conical valve springs
- 24 titanium retainers
Compatibility – BMW and Toyota models with the B58 engine
- 1 Series F20 F21 M140i(x) B58 2016–2019
- 2 Series F22 F23 M240i(x) B58 2017–2020
- 3 Series F30 F31 F34 340i(x) B58 2016–2017
- 3 Series G20 G21 M340i(x) B58 2017+
- 4 Series F32 F33 F36 440i(x) B58 2016–2017
- 4 Series G22 G23 M440i(x) B58 2017+
- 5 Series G30 G31 540i(x) B58 2017–2020
- 6 Series G32 640i(x) B58 2017–2019
- 7 Series G11 G12 740i(x) B58 2016–2020
- 8 Series G14 G15 G16 840i(x) B58 2020
- X3 Series X3 M40i(x) B58 2017–2020
- X4 Series X4 M40i(x) B58 2018–2020
- X5 G05 X5 40i(x) B58 2018–2020
- X6 G06 X6 40i(x) B58 2019–2020
- X7 G07 X7 40i(x) B58 2019–2020
- Z4 G29 Z4 M40i B58 2017–2020
- Toyota A90 GR Supra B58 2020
Part number
SPRK-B58B
Fitting and support
Professional installation is recommended for all valvetrain work. For expert fitting, choose Nforcd in Warwickshire. Request a fitting quote at Sales@nforcd.com.
Images are for illustration purposes.
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