d or valve

Hi, Been having a few issues with my lcr since the AmD rr day, been advised by quite a few people that the hose that runs from the metal charge pipe to the dump valve is really soft(really really soft), Just wondering if that would have an effect on boosting as the car is defo not running like...

right just fitted a new forge 007p dv as the bailys one that was on it was leaking and now my boost gauge is reading about 5 psi lower it use to boost to 16 psi then drop and hold at 15 psi but now it seems to boost up to about 12-13 psi and hold ther:confused: is this becouse it dont have to...