GFB SV52 blow-off valve 52.5 mm

The GFB SV52 is an extremely compact, high-flow blow-off valve (BOV) for high-performance turbocharged engines.

With the weld-on adapter, it is only 86 mm high, which is 10 mm less than the nearest competing product, while also providing greater flow.

Key questions when choosing a blow-off valve for a forced-induction engine:

• Will it withstand the pressure? Yes – the rated pressure is up to 300 psi.
• Does it provide sufficient flow? Yes – according to the manufacturer, it outflows other valves in its class.
• Is it compact enough for the engine bay? Yes – at 86 mm high, it is 10 mm lower than the nearest competing product.

High strength

The SV52 is designed for use in high-boost environments and has a rated pressure of up to 300 psi.

The kit includes two springs and a spring preload adjustment system. This allows you to optimise the valve for optimal throttle response and faster boost pressure recovery after shifting, without purchasing additional springs.

It is suitable for engines with intake manifold vacuum from 5 to 22 inHg (17–74.5 kPa or 2.5–11 psi of vacuum).

BODY

High pressure resistance is provided by a one-piece body CNC-machined from a single piece of aluminium. This construction provides high strength without unnecessary weight.

PISTON

The anodised piston bore creates an extremely hard, low-friction surface along which a one-piece 52.5 mm aluminium piston slides. It is designed for long-term operation through numerous operating cycles and uses a special arrangement of Viton O-ring seals.

DESIGN

Compared with a conventional diaphragm design, the SV52 uses a piston mechanism that provides greater strength and reliability at high boost pressure. A blow-off valve is exposed to frequent pressure changes – every time the engine accelerates and the throttle is lifted.

Under boost pressure, the diaphragm repeatedly collapses in on itself, then stretches under vacuum, which can eventually cause it to fail. The piston, on the other hand, is not sensitive to this type of load and can operate at very high pressures, temperatures and through numerous operating cycles.

The special mounting method of the SV52 valve reduces unnecessary dimensions. The V-band mounting has been eliminated, so the piston and discharge openings are positioned lower, while the valve’s total height is only 86 mm.

Suitable for: universal use (not vehicle-specific).