My car is stage 1 with no mods to the airbox etc
I recently bought from another member a forge 007 to replace my standard valve.
Under normal driving there was no difference in sound, just the usual quiet pst, however under heavy throttle when lifting off to change gear the valve sounded louder and higher pitched, like a wheezing noise.
I therefore fitted the yellow spring, this made little or no difference.
Is this normal, should I fit one of the the spacers, or will it have a boost leak or something?