Now you can fine tune your Blow Off/Diverter Valve to the exact needs of your engine with this complete tuning kit. The strongest spring is the red, followed by the blue, yellow and finally the green which is the weakest. We normally supply 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 losing 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. Please note - fitting a stronger spring into a valve will not increase boost pressure unless existing pressure is being lost. Failure to allow the valve to operate by installing a spring which is to strong may cause damage to the turbocharger. Please note - the red coded springs should not be installed in the DVR or DV007 diaphragm valves. This kit is not suitable for the FMDVMSP02, FMDVSPLTR, FMRSR, FMRSA,FMDVFSITV/FMDVFSITVR, FMFSITV/FMFSITVR. Please contact us if you are uncertain whether this kit is suitable for your valve