dboonem

just recently noticed i no longer build boost while accelerating, psi will push to 0 to 3 psi then drop back to zero while in high rpms, this is in all gears. When purchased i could hear a defined whine from the supercharger which is no longer present.

I also recently started to notice a depressurization noise ? when turning off the car seems like its coming under or near the air filter/box, attached is a vid of said noise.

stock 2010 gt500

kenthicken

Sounds like belt slip. Tensioner?

jwog666

the noise you hear from the air box is normal, its caused by cylinder pressure escaping back into the intake and air inlet system past a partially open intake valve after the engine has been shut off. if you are using factory gauge to determine your boost, remember they arent very accurate, to be sure you would need an actual boost gauge to verify