HKS 71008-AN029 Super SQV4 Dual Blow Off Valve Kit for Nissan GT-R R35 VR38DETT

Vehicle Fitment

• 2009-present Nissan GT-R R35 (VR38DETT 3.8L twin-turbocharged V6, AWD - all trims including Premium, Black Edition, Track Edition, NISMO)

Fitment Notes

• This is the direct replacement ("REPLACE") kit - it mounts in the OEM bypass valve locations on the factory intercooler piping. It does NOT include new aluminum intercooler pipes. For the kit that replaces both the OEM bypass valves AND the OEM rubber intercooler hoses with polished aluminum pipes, see HKS 71008-AN027
• The R35 GT-R uses two turbos and two factory air bypass valves (one per turbo) - this kit includes two SQV4 BOVs to replace both OEM bypass valves simultaneously
• Each SQV4 unit includes both a triple fin section (for atmospheric/sound configuration) and a recirculation fitting (for return-to-intake configuration) - the owner selects which configuration to install
• Recirculating configuration is recommended when retaining the factory MAF-based engine management - routing blow-off air back into the intake preserves the MAF signal and eliminates the risk of rich stumble, idle hunting, or stalling on deceleration
• Atmospheric configuration (triple fin installed) is suitable for MAP-sensor (speed density) tunes where MAF output is not used for fueling calculations - delivers the full audible SQV high-frequency sound
• This product is not CARB legal and is not for sale in California or CARB states

Features

• Dual SQV4 kit for twin-turbo coverage - one SQV4 unit per turbocharger, replacing both OEM air bypass valves in a single installation and ensuring balanced pressure relief across both banks of the VR38DETT's twin-turbo system
• Sequential pull-type dual valve structure - a small primary valve opens first at any deceleration event for ultra-fast initial actuation, followed by the larger secondary valve for full-volume discharge. The pull-type design uses boost pressure to hold the valve sealed on-throttle, making it essentially boost-leak proof under load - sealing performance increases with boost pressure
• Differential pressure control system - monitors the pressure differential between the intercooler side and intake manifold vacuum to control valve opening with precision across the full operating range, from idle and light-throttle cruise to peak boost at high RPM. This allows stable operation on stock boost as well as significantly elevated boost levels without adjustment
• Nickel-plated die-cast metal secondary valve swaged to primary valve - the SQV4 generation upgrade; the metal die-cast secondary valve is swaged (mechanically deformed and joined) directly to the primary valve for superior structural integrity compared to previous-generation clip retention
• Stainless steel C-clip and spring - additional internal sealing retention hardware for improved durability and consistent sealing force across the valve's service life
• Silver-coated aluminum die-cast body - lightweight, rigid, and corrosion-resistant with a polished silver appearance that visually enhances the VR38DETT engine bay's already aggressive look
• Triple fin sound design - when the triple fin section is installed (atmospheric configuration), the three-spoke internal geometry produces the iconic HKS SQV high-frequency metallic blow-off sound - significantly louder than the near-silent OEM bypass valves, transforming the GT-R's audible character during hard driving
• Configurable recirculation or atmospheric operation - both the triple fin (atmospheric) and recirculation fitting are included, giving the owner full flexibility to configure each BOV for their specific tune and noise preference
• Block-off plugs and vacuum line filters included - vacuum line filters prevent contamination of the valve's vacuum signal reference line; block-off plugs are used to cap ports not utilized in the chosen configuration
• Direct OEM bypass valve replacement - mounts to the stock intercooler pipe bypass valve ports using factory locations, requiring no custom fabrication or pipe work
• Made in Japan by HKS

Specifications

• Part Number: 71008-AN029
• Series: Super SQV4 (Super Sequential Blow Off Valve, 4th generation)
• HKS Product Name: Super SQV4 GT-R R35 VR38DETT (Replace)
• Compatible Platform: Nissan GT-R R35
• Compatible Engine: VR38DETT (3.8L twin-turbocharged V6)
• Kit Configuration: Dual (2 BOV units - one per turbo)
• Installation Type: Direct OEM bypass valve replacement (no new intercooler pipes)
• Valve Operation: Pull-type sequential (dual valve - primary + secondary)
• Secondary Valve: Nickel-plated die-cast metal, swaged to primary valve
• Retention: Stainless steel C-clip and spring
• Body: Silver-coated aluminum die-cast
• Sound Design: Triple fin (atmospheric) or recirculation fitting (MAF-safe)
• Configuration Options: Atmospheric or recirculating (hardware for both included)
• CARB Legal: No - not for sale in California or CARB states
• Country of Manufacture: Japan
• UPC: 4957266265444

Included Components

• 2x HKS Super SQV4 blow off valve head units (silver aluminum die-cast)
• 2x Triple fin sections (for atmospheric configuration)
• 2x Recirculation fittings (for return-to-intake configuration)
• 2x Block-off plugs
• 2x Vacuum line filters
• 1x Vacuum hose

Product Description

The HKS 71008-AN029 is the Super SQV4 direct replacement kit for the factory air bypass valves on the Nissan GT-R R35 (VR38DETT). The R35's twin-turbo layout uses two OEM air bypass valves - one per turbocharger - and this kit replaces both simultaneously with a pair of SQV4 units, mounting directly into the OEM bypass valve ports on the factory intercooler pipes without requiring any new intercooler piping. This distinguishes it from the 71008-AN027 kit, which pairs the SQV4 BOVs with new polished aluminum intercooler pipes; the 71008-AN029 is the appropriate choice for owners who want the SQV4's performance and sound characteristics without replacing the existing intercooler pipe system.

The SQV4's dual sequential valve architecture provides the key technical advantage over the OEM bypass valves: a small primary valve opens first under any deceleration for immediate, low-threshold actuation, followed by a larger secondary valve that handles the full-volume boost discharge. The pull-type relief design holds both valves sealed by the action of boost pressure acting on the valve face when on-throttle - so the valve becomes more reliably sealed as boost increases, rather than requiring progressively higher spring tension. The SQV4 generation introduces a nickel-plated die-cast metal secondary valve swaged directly to the primary valve for improved structural integrity, plus a stainless steel C-clip and spring for enhanced sealing retention and long-term durability under the sustained high-boost cycling characteristic of the GT-R's aggressive power delivery.

Each SQV4 unit in the kit is supplied with both a triple fin section for atmospheric configuration and a recirculation fitting for return-to-intake routing. In recirculating mode (recommended for vehicles retaining the factory MAF-based tune), the blow-off air is returned to the intake upstream of the turbo inlet, preserving the MAF signal and eliminating the lean condition, idle stumble, or stalling that can occur when metered air is vented to atmosphere on a MAF system. In atmospheric mode - appropriate for MAP (speed density) tunes where MAF output is not used for fueling - the triple fin section produces the signature HKS SQV high-frequency blow-off sound, a dramatic and audible upgrade over the near-silent OEM bypass valve operation. Block-off plugs and vacuum line filters are included for a clean, complete installation in either configuration.