The Turbosmart Electronic StraightGate eSG40 External Wastegate is the most compact butterfly-style external wastegate in the StraightGate lineup, engineered specifically for tight engine bays and demanding packaging constraints. Despite its smaller footprint, the eSG40 delivers exceptional exhaust flow and near-linear boost control thanks to its zero-offset butterfly valve design and full electronic actuation.
Derived from the award-winning eSG50, the eSG40 eliminates traditional boost control limitations by removing reference hoses, springs, and diaphragms entirely. Instead, boost control is handled via an integrated servo motor and Turbosmart’s zero-backdrive gearbox, providing precise electronic valve control with reduced current draw and excellent stability under high exhaust drive pressure.
The zero-offset butterfly valve is centrally pivoted and exposed to equal exhaust pressure on both sides, making it inherently self-balancing. This design minimizes actuation force requirements, improves response time, and allows for a significantly wider tuning window compared to conventional poppet-style wastegates. The straight-through flow path further enhances efficiency by eliminating the 90-degree flow redirection found in traditional wastegate designs.
The eSG40 includes onboard actuator temperature and valve position sensors, available in both analog (0–5V) and digital (PWM) outputs, enabling advanced boost control strategies, real-time monitoring, and precise calibration. With appropriate exhaust manifold priority, the StraightGate40 can support control from near-zero boost to maximum boost with exceptional repeatability.
Manufactured from high-temperature stainless steel materials and validated in-house, the eSG40 is designed for extreme motorsport environments. Integrated liquid cooling provisions further enhance actuator stability and longevity in high-heat applications.
FEATURES
- 40Â mm (1.57") zero-offset butterfly-style valve
- Compact design for tight engine bay fitment
- Straight-through flow path for high efficiency
- Full electronic actuation (no springs, diaphragms, or reference hoses)
- Dual H-bridge electronic input
- Stainless steel (630) butterfly and shaft
- Stainless steel (347) wastegate body
- Heat-treated stainless steel (431) V-band clamps
- Self-balancing valve design for stability under high drive pressure
- Onboard actuator temperature sensor (0–5V analog)
- Onboard valve position sensors (0–5V analog and PWM digital)
- Clockable actuator position (3 × 120° orientations)
- 360° mounting options via V-band connection
- Liquid cooling provision for actuator stability
- 7-wire unterminated flying lead wiring loom
APPLICATIONS
- Tight engine bay turbo systems
- Advanced electronic boost control setups
- High-performance street, track, and motorsport builds
- Applications requiring precise, fast, and repeatable boost control
INSTALLATION INSTRUCTIONS
eSG Electronic StraightGate Instructions
IMPORTANT NOTE
This product requires compatible electronic boost control hardware and tuning strategy. Professional installation and calibration are strongly recommended. This product does not carry a CARB EO and is intended for race and off-road use only.
