Your valve tuning kit you will find four springs.
The strongest spring is the red, followed by the blue, yellow and finally the green which is the weakest.
Forge Motorsport normally supplies our valves, unless requested differently, with a spring that will match the tension of the manufacturer’s original fitment valve. However, as many owners undertake tuning modifications some may wish to re-tune the valve characteristics to suit a given application.
If you are finding that the valve is dumping more than required or you are loosing boost pressure it is normally an indication that a stronger spring is required. Conversely if the valve is failing to dump it may be necessary to install a weaker spring.
Valve Spring color coding
Green - 5-15 PSI
Yellow - 15-23 PSI
Blue - 23-30 PSI
Red - 30 + PSI
The above figures are estimates only and should only be considered as a guideline