I've got a Forge Re-circulating dump valve fitted to my 2005 JDM STI that's running around 350bhp at 1.5bar.

My question is what colour spring should I have fitted? Also, what would happen if the spring fitted was too soft or too stiff?

Thanks in advance

 

normally the red spring at that boost, too weak and it can affect how it holds boost and too strong doesnt ever really cause a problem, just wont go off as often, red spring is the strongest as far as im aware

 

Check the forge website it tells u what spring for what psi

 

the red spring

 

Cheers lads. I'll get the red spring as I wasn't convinced the Blue spring I have now was stiff enough. Thanks again