i ordered a big blue spring that is 14.5 psi sapposedly and installed it. car only hits 9psi with the spring. the 9psi spring i had in the gate is the exact same one i ordered as a 14.5psi spring. anyone know anything about this? now i instal my boost controller and try to get the car to 15psi where it was tuned to and as soon as i hit about 11psi the car starts backfiring reallly realllly loud. boost cut is set at 16.5psi and i dont think it is hitting that. Unless the boost gauge is reading way off. i am thinking bad map sensor? i have a GM3bar. I want to drive this thing i just got my 3" d/p and exhaust all finish, changed the oil, new plugs and new gaskets whereever they were leaking. so car runs beautiful other than this problem i am having.

 

What manifold do you have? You may have a hairline crack around a weld if your using a crummy manifold. This happened to me. I couldn't increase boost much at all. Good Luck.

 

the spring was wrong. they sent me the right one and now sometimes it backfires between 5k and red line. it is very strange. boost gauge only reads 10psi but it definitly is hitting 15psi. it is a drag gen III manifold btw. Sometimes it will pull real hard all the way to redline but sometimes it will start backfiring like crazy now.

 

are you sure they sent you a 1bar spring. If your gauge is reading 10psi. If you have a electronic boost controller what is it saying?