During the development of the X3 BOV, we had 15 different springs made to optimize throttle transitions in on/off/on/boost situations. During the spring selection process, it was determined that there was a razor thin line between having good on/off/on throttle response from the valve and having the valve closed at idle. On most X3's, the BOV piston will sit on or slightly above the sealing ledge of the valve body with our standard X3 spring and the adjustment cap tightened all the way. This is normal. A few X3's with nearly perfect engine compression may pull the valve open more. The reason is these engines will usually produce more vacuum and therefore overcome the spring preload. If you find that your EVP BOV is open at idle and are concerned about it (generally this is a non issue) we have alternate springs with more preload to choose from. A stiffer spring may sacrifice some responsiveness.During the development of the X3 BOV, we had 15 different springs made to optimize throttle transitions in on/off/on/boost situations. During the spring selection process, it was determined that there was a razor thin line between having good on/off/on throttle response from the valve and having the valve closed at idle. On most X3's, the BOV piston will sit on or slightly above the sealing ledge of the valve body with our standard X3 spring and the adjustment cap tightened all the way. This is normal. A few X3's with nearly perfect engine compression may pull the valve open more. The reason is these engines will usually produce more vacuum and therefore overcome the spring preload. If you find that your EVP BOV is open at idle and are concerned about it (generally this is a non issue) we offer this springwith more preload. A stiffer spring may sacrifice some responsiveness.
- Part Number(s):
- 100RC0005
