Dual Piston Blow off Valve V2 (BOV) BMW N54 135I 335I 535I E90 E92 E88 TWIN TURBO

Carrot Top Tuning Dual-Piston Atmospheric Blow-Off Valve – V2

Designed for performance turbocharged vehicles equipped with a mass air flow (MAF) sensor, the Carrot Top Tuning Dual-Piston Atmospheric Blow-Off Valve V2 delivers fast response, reliable boost control, and the unmistakable “whoosh” sound enthusiasts expect — without the common drivability issues found in single-piston or diaphragm-style valves.

This valve is designed to connect directly to factory (OEM) charge pipes and is also compatible with most aftermarket charge pipes that accept a standard blow-off valve flange or hose-style connection.

Billet Construction & Improved V2 Design

Machined from high-quality billet aluminum, this Version 2 valve features a revised internal layout for improved airflow and durability. The updated design replaces the previous Delrin secondary piston with a fully billet aluminum piston for increased strength and longevity under high boost and heat conditions.

The valve is fully serviceable and easy to maintain, featuring a twist-off top hat that allows quick disassembly for cleaning or inspection.

How the Dual-Piston System Works

Unlike traditional single-piston blow-off valves that rely on a single spring and vacuum signal, this valve uses a counter-balanced dual-piston design with independent spring rates to improve drivability on MAF-based vehicles.

• Lower Primary Piston: Remains fully closed at idle and during light vacuum, preventing unmetered air from escaping.
• Upper Secondary Piston: Uses a lighter spring and responds instantly to throttle lift, allowing rapid venting under boost.

This design prevents the valve from leaking air at idle — a common issue with single-piston or diaphragm valves — which can otherwise cause rough idle, stalling, or inconsistent fueling.

Performance Benefits

• Faster throttle response between shifts
• More consistent boost pressure retention
• Reduced risk of idle and drivability issues on MAF vehicles
• 100% atmospheric venting for maximum sound and response
• Improved sealing compared to single-piston designs

Key Features

• Dual-piston, counter-balanced design
• Fully billet aluminum construction
• Version 2 internal redesign for improved airflow
• Billet secondary piston (no Delrin)
• Easy service and maintenance
• Aggressive atmospheric discharge sound

Built for enthusiasts who demand reliability, performance, and sound — the Carrot Top Tuning Dual-Piston Atmospheric Blow-Off Valve V2 is a proven upgrade for serious turbo setups.

What’s Included

• 2x Dual-Piston Atmospheric Blow-Off Valve
• 2x Inlet Pipe Plug
• 4x Hose Clamps
• 2x Silicone Adapter (BMW N54 applications only)