[CUSTOEM]

Fellas,
If I'm looking to purchase a 50mm Tial BOV... running 550-650rwhp - - what size spring should I be interested in?

 

[mitulparmar787]

How much boost are you going to run to make that power? It's all dependant on that .

 

[IGGYWOOWOO]

you guys have this all wrong! To select BOV spring size, you must know how much vacuume you pull at idle.

Here : http://www.tialsport.com/documents/w3_tial_bov50_sp.pdf