have got the fm dv on my01 wrx it comes as standard vwith the red spring , i have got the blue spring as well is it much of a job to change over? or do i just undo all the allen bolts and change over, any thing that i should watch out for?? is the blue spring that much noisier ?
cheers Darren

 

the red spring is a bit hard but at high boost it does make a chatter noise. I swapped over for the blue which gives a much nicer thskkkkkkkk at lower revs. It is as easy as undoing the allen bolts but be carfull not to let bits go flying everywhere when you undo it.

It's an easy job though

 

Forgot to say, the thskkkkkk gets longer and louder the more times you *dump* so to speak, it's getting the spring worn in a bit first.