In The Race To Create The Most Compact And Highest Flowing Blow-Off Valve, GFB’s SV52 Pulls Ahead Of The Pack.

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

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 SV52 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 SV52 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.

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.

Patent Pending