i had a problem with my tial q surging so i checked the engine vac at idle and had around 6-8 in. of vac with skunk 2 pro1's and pnp head. so i got the lightest spring tial had but now with the car parked the valve will stay 3/4 open at idle and will fully open with any throttle. now i cant see under the hood while driving but i cant really hear much of a "blow off" so im not sure its fully closed under load either. has anyone tried to put washers under the springs to raise the spring rate/pressure?

also how loud should this bov be? ive yet to hear it opperate correctly and am curious to know how noticable it will be over the sound of the full 3in unmuffled exhaust?

 

it is in vacuum so it will be open @ idle... When in boost it will close..

 

yup should be open at idle. i could never hear mine with a 3" open downpipe.

 

Its supposed to be open some but not fully at idle. You can try a stiffer spring.

We were getting surge on a SRT-4 so we went with a softer tial spring. But it was open full at idle so we shimmed it with 1 large washer. just drilled out the center.

 

go to tials site, there is a chart, pick your spring according to your engine vacuum.

 

if you have 6-8in/hg vac there is no way the -6psi spring is open at idle...it cracks at -12in/hg.

where do you have your boost/vac referenced?