HKS Super SQV4 Blow Off Valve Recirculation Kit (Normal Box) - 2020-2023 Toyota GR Supra

SSQV4 Blow Off Valve Recirculation Kit for the 2020-2023 GR Supra

The HKS Super SQV4 Blow Off Valve Recirculation Kit for the 2020-2023 Toyota GR Supra is the factory airbox compatible recirculation version of the SSQV4. Where the AT022V is designed for use with the HKS R/S intake, the AT021V is calibrated for use with the factory airbox or equivalent setups. It routes vented pressure back into the intake tract to maintain the ECU's air mass metering, preventing the fueling stumble that occurs when boost pressure is vented to atmosphere on a MAF-based system.

Specs & Highlights

• SSQV4 blow off valve with recirculation routing
• Calibrated for use with OEM airbox
• Maintains ECU air mass metering
• Prevents fueling stumble on throttle re-application
• Includes all hardware and adapters
• Fitment: 2020-2023 Toyota GR Supra

25mm Return Outlet, Factory Intake Routing

The AT021V uses the same 38mm SSQV4 valve body as the atmospheric version but with a recirculation outlet port sized at 25mm diameter. The recirculation routing on the normal airbox (OEM) application returns to the intake pipe between the airbox outlet and the throttle body inlet, where it enters the charge air path approximately 200mm upstream of the throttle. This location ensures the returned air is re-measured by the MAF sensor on the next intake cycle, maintaining ECU air mass accounting.

Maintaining ECU Air Mass Accounting

The AT021V sits between the stock blow off valve and a full atmospheric setup in the HKS Supra BOV lineup. It provides the SSQV4 valve mechanism. With its superior construction, progressive sequential action, and distinctive sound relative to the factory valve, while maintaining the closed-loop fueling behavior the stock ECU requires. For Supra owners running the stock intake who want the HKS BOV upgrade, this is the correct version.

This Version is for the OEM Airbox Only

The choice between AT021V (normal box / stock intake) and AT022V (HKS R/S intake) is determined entirely by your intake configuration. Both use the same SSQV4 valve mechanism. Both are recirculation systems. The difference is the adapter geometry for the intake pipe connection. Ordering the wrong version means it will not connect correctly.

The FT Breakdown

Most street Supras running stock or light bolt-on setups will want the AT021V. The AT021 atmospheric version is for builds with aftermarket ECU management where atmospheric venting is acceptable. When in doubt, recirculation is safer for stock and near-stock ECU setups. The 200mm upstream return connection point is far enough from the throttle to allow complete mixing of the returned air with the incoming charge before it reaches the MAF sensor. That mixing distance is what prevents the MAF from seeing a pressure pulse and mistaking it for an airflow measurement — the AT021V return routing is calibrated, not arbitrary.