Purchase A GFB Boost Controller AND A Blow Off Valve In A Single Purchase, Receive A 5% Discount .
Purchase A GFB Boost Controller, Blow Off Valve AND A Wastegate In A Single Purchase, Receive A 10% Discount.
The Discounts will be reflected in the shopping cart.
GFB TMS valves are designed with maximum throttle response in mind first, followed by the ability to vent to atmosphere for noise (if desired) on cars that typically don’t allow atmosphere venting.
The piston-type valve design used by GFB satisfies the broadest range of design requirements and applications, which is why it continues to be used. For example, the dual outlet Hybrid design pioneered by GFB back in 1999 is only possible with a piston-type valve – dual outlets and 50/50 venting simply cannot be done with a factory poppet type valve.
Sealing a piston in a bore is simple, right? Use an O-ring and no air will be able to leak past – this is how hydraulic and pneumatic pistons and rams work. GFB TMS valves however, do not use an O-ring on the piston as is sometimes found on other brands, for two important reasons:
Friction in the piston travel can cause undesirable side-effects such as poor throttle response, compressor surge, idling problems, stalling and backfiring.For optimum throttle response, the piston must be able to move freely in reaction to very small changes in pressure (the forces involved can actually be very small). O-rings create significant friction, no matter how loosely compressed, and worse still, the amount of friction varies greatly depending on the amount of lubrication, temperature, and how long the O-ring has been stationary (they tend to take a “set” after a while of not moving, and require significantly more force to get moving again).It is simply not possible for a piston-type valve to operate properly with even the smallest amount of friction added by an O-ring
Instead of O-rings, GFB TMS valves have multiple design features that offer the bestbalance between lowest friction, longest service life and minimal leak. These features are:
GFB products are manufactured exclusively on CNC machines capable of holding tolerances to +/- 0.01mm. This is essential since the piston-to-bore clearance iscritical to ensure good sealing and low friction.
The piston is made from brass, which offers good corrosion resistance and machining properties for tight tolerances, and relatively low friction as it is often used in bearings and bushings. The bore is anodised aluminium, which also offers good machining properties and therefore tight tolerances, whilst the anodising results in an extremely hard and smooth finished surface that resists wear.
In lieu of an O-ring, GFB’s pistons use a low-friction Ertalyte™ piston ring, designed much like the rings used on high performance engine pistons to spring outwards against the bore to aid sealing.
If further proof of argument against the use of O-rings is required, consider that the cost of O-rings in bulk is minimal –usually cents per piece. GFB’s piston design already features a groove into which the piston ring fits, so no design change would be required to swap to an O-ring. Yet GFB choose the best performance by design, even though the Ertalyte™ piston ring and tight tolerances cost more to produce that O-rings.