What spring to use

[1quickturbosix]

So I just purchased a Forge BPV. I know it comes with a couple different springs. Could someone shed some light as to which one works the best. Im currently stock besides the Cobb AP and a K&N Drop in filter. And what are some of the advantages and disadvantages of the different colors?

[coyfish]

Do a search for forge BPV. Lots of info on springs.

Basically most people use blue spring with 1 or 2 shims. The red spring is only if you push 20 psi (aka upgraded turbo with boost controller).

Start with the blue spring and add shims. See which feels best for you. I use blue with 2 shim.