GFB Deceptor Pro II (part T9507) - Manual (Page 5)

When powered up the volume dial rim will glow red, and will automatically dim 3 seconds after
the last adjustment to reduce unnecessary glare. The position of the dial is directly
proportional the venting bias - turning the dial fully anti-clockwise sets the valve to 100% recirc,
fully clockwise results in 100% atmosphere venting, and any ratio is possible in between.
The controller also features a program button on the rear of the casing. This can be used to limit
the range of the atmosphere-venting bias of the Deceptor Pro II. For example, if you find
through experimentation that your car does not like more than 60% atmosphere venting, you
can program the controller so full travel on the dial gives you only 60% movement at the valve.
To use this feature, set the dial in a position that you want as your maximum atmosphere-
venting limit, then press and hold the program button until the dial flashes. The unit will now
record this position as the maximum atmosphere-venting limit. Now when you turn the dial fully
clockwise, the Deceptor Pro II will only open as far as the point which you have just set. For
example, if you pushed the button with the dial set in the middle (50% atmosphere venting), full
travel of the dial will now move the valve from full recirc to 50% atmosphere-venting only.
Every time the button is pushed and held, the position of the dial will determine the maximum
venting bias of your Deceptor Pro. So to re-set the controller to allow the full range again,
simply turn the dial fully clockwise and push the button.
Typically, most un-modified engines will allow 100% atmosphere venting with no problems.
However, some combinations of modifications can result in backfiring if high proportion of
atmosphere venting is used, in which case the solution is simply to dial back the amount of air
vented to atmosphere until the problem is resolved – this is one of the key benefits of the
venting bias adjustment feature.
Do not be afraid to experiment with the spring and noise settings, no harm will come to the
engine if wrong setting is used.
GFB blow-off valves are designed to be as maintenance-free as possible. In most cars the
small amount of crankcase and rocker-cover oil vapor that is directed into the intake system is
enough to keep the piston well lubricated indefinitely. However, if you notice the sound of the
valve changing over time (e.g. slow response time, intermittent operation), or if you can see
that the piston is not moving smoothly, it may require a clean and re-lube.
Cleaning Procedure: Remove the four screws holding on the cap, taking care as the spring will
try to push the cap off as the last screw is removed. Remove the spring and the brass piston,
and wipe any grime from the inside of the valve and the piston with a rag. Apply normal engine
oil to the piston and the inside of the bore, and re-assemble.
Adjusting the sound
mAINTENANCE
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 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/drive-train components.
GFB recommends that only qualified motor engineers fit this product. Warranty is for the period of one year
from the date of purchase and is limited only to the repair or replacement of GFB products provided they are used
as intended and in accordance with all appropriate warnings and limitations. No other warranty is expressed or
implied.