TiAL blow off valve spring to suit either a TiAL 50mm or Q-Style blow off valve.

50mm

Engine Vacuum Reading                        Colour                          Use Spring

-22 and -23 in/HG                           Pink                      -12 PSI (-24 in/HG) 

-18 and -21 in/HG                           Un-painted            -11 PSI (-22 in/HG) 

-14 and -17 in/HG                           White                    -9 PSI (-18 in/HG) 

-10 and -13 in/HG                           Black                     -7 PSI (-14 in/HG) 

Q-Style

Engine Vacuum Reading                        Colour                          Use Spring

-20 and -21 in/HG                           Pink                      -11 PSI (-22 in/HG) 

-16 and -19 in/HG                           Un-painted            -10 PSI (-20 in/HG) 

-12 and -15 in/HG                           White                    -8 PSI (-16 in/HG) 

-8 and -11 in/HG                             Black                     -6 PSI (-12 in/HG)