GFB DV+ (part T9352) - Manual (Page 3)

The DV+ difference
Whilst the DV+ might look pretty basic, there is a very significant difference in the way it operates compared to
the factory diverter valves, and other aftermarket products on the market.
The factory diverter uses the solenoid to directly actuate the valve. The problem with this method is the actuating
forces are very weak – the return spring is weak, and the solenoid coil is weak when the valve is fully closed
because of the long 5mm stroke (magnetic force diminishes significantly as distance increases). So increasing the
spring pre-load of the factory valve doesn’t help, since the solenoid coil will have trouble opening the valve.
The GFB DV+ uses the factory solenoid coil, but its role is to control the pressure signal used to actually open and
close the piston, which is known as “pilot actuation”. This means the forces that the solenoid coil deals with are
much lower, and its operation is therefore reliable at much higher pressure. The solenoid operates a plunger that
controls pressure to the back of the piston. When the solenoid is off, there is equal pressure on both sides of the
piston, but importantly, the area the pressure acts on is about 25% LARGER on the back of the piston than the
front. So there is 25% more force holding the piston shut than there is pushing it open. The bottom line is, it
doesn’t matter how much boost you run, the DV+ will never crack open.
When the solenoid activates, the pressure on the back of the piston is relieved, and it can then open. The benefits
of this system are reliable valve actuation at high boost, no leakage, and being all metal parts, no failures due to
increased temperature.
Because the DV+ has a higher closing force than opening force, it doesn’t actually NEED a return spring behind the
piston to work – it will open and shut, and hold boost, just as reliably with or without the spring.
However, using the spring means that unlike the factory diverter, the GFB DV+ will open in response to both
boost pressure AND the ECU signal operating the solenoid. That is, if the solenoid is triggered but there is no
boost, it won’t open. If the solenoid is triggered and there is boost, the valve will open only as long as there is
boost pressure pushing it open. It will close
itself as boost pressure in the intercooler
drops, even if the ECU is telling it to open. This
operation method results in less turbo lag,
because the valve is not opened unnecessarily.
This is the basis behind GFB’s TMS principle,
which is this; turbo lag is minimised when the
valve only vents just enough air to prevent
compressor surge – the graph opposite
illustrates the reduction in lag. To read more
about the TMS principle, visit our website:
www.gfb.com.au
This product is intended for racing use only, and it is the owner’s responsibility to be aware of the legalities of fitting this product
in his or her state/territory regarding noise, emissions and vehicle modifications. GFB recommends that only qualified motor
engineers fit this product.
Materials and workmanship of this product are covered by a lifetime warranty. Moving components subject to wear are covered
for a period of one year from the date of purchase. Warranty is limited only to the repair or replacement of GFB products
provided they are installed and used as intended, and in accordance with all applicable warnings and limitations. No other
warranty is expressed or implied.
GFB products are engineered for best performance, however incorrect use or modification of factory systems may cause damage
to or reduce the longevity of the engine or drivetrain components.