In the race to create the most compact and highest flowing blow-off valve, GFB’s SV52 pulls ahead of the pack.

Standing only 86mm tall (including the weld-on adaptor), the GFB SV52 is 10mm shorter than the nearest competitor, AND flows more!

Consider these questions when you’re looking for a BOV for your high-powered, forced induction engine:

Will it handle the pressure?…………………………….. YES! Is 300psi enough?
Will it flow enough?…………………………………………   YES! It outflows everything else in its class!
Is it small enough to fit my engine bay?…………..YES! 10mm shorter than the nearest competitor!
Will it last?…………………………………………………………. YES! It comes with a lifetime warranty!

Strength is important;

Realizing that a high-flowing valve like this will see duty in some high-boost environments, we made sure the SV52 tops the class in that category as well, giving it an astonishing boost pressure rating of 300psi!

The GFB SV52 50mm BOV also includes 2 springs PLUS a spring pre-load adjustment system so you can dial it in for optimum throttle response and boost recovery after gearshift, without resorting to the costly hit- and-miss approach of purchasing extra springs.

**Suits engines with manifold vacuum ranging from 5-22inHg (17-74.5kPa, 2.5-11psi vacuum)

» BODY

The GFB SV52’s unparalleled pressure capacity starts with a monobloc body design, CNC machined from a single aluminium billet that ensures strength without adding unnecessary bulk.

» PISTON

The anodized piston bore creates an extremely hard and low-friction surface on which the single piece aluminum 52.5mm piston glides, and will continue to do so over countless cycles. It features an arrangement of Viton o-ring seals unique to GFB.

One is positioned on the face of the piston to seal incoming boost pressure, the other rides in a groove on the piston that engages the specially shaped cylinder wall with varying amount of compression, to ensure optimum sealing when the valve is closed, and low friction during the opening and closing movements.

» DESIGN

Why do we use a piston instead of the more common diaphragm design?

Strength and reliability is the primary factor, something that a diaphragm simply cannot match in a high-boost BOV environment. Diaphragms have their place (we use them in our wastegates), as they offer low friction and good sealing capability. However, a rolling diaphragm is only designed to receive a net pressure on one side, which essentially “inflates” it against the walls of the chamber in which it resides, exactly how it is used in a wastegate.

However, a BOV is exposed to frequent pressure reversals – every time you accelerate and lift off.
For a diaphragm, this means it is repeatedly collapsing on itself under boost, then inflating under vacuum. Eventually, this leads to diaphragm failure. A piston on the other hand is immune to this issue, and will continue to operate under the most extreme pressure, temperature, and cyclic conditions.

The unique mounting method of the SV52 is one of the ways we’ve been able to save unnecessary bulk.
By eliminating the v-band style mount, the piston and its venting ports can sit much lower, which reduces the overall height to a number others can’t match.

GFB SV52 50mm BOV