I have a 96 turbo maped to 300BHP with as light flywheel and we have jsut rebuilt the engine. I have a boost control problem so have plumbed the wastegate to the turbo outlet without any of the electronics as itis overboosting past 5Krpm. i have found that by unplugging the boost solenoid it wont overboost. anyone got some ideas to the problem. i am coming to the conclusion that it is a problem with the ecu map. i have also changed the map sensor and solenoid that it is plumbed to and the boost solenoid. if the map sensor is plumbed directly into the manifold it still overboosts

 

probably the cold weather?

 

As above - Boost valve duty is probably a bit high for the fairly cold weather we're experiencing

What ecu are you using? - Is this controlling the boost solenoid or are you using a boost controller?
What is the boost set to? - What are you hitting?
Is it overboosting by a set amount through the rev range, or does it creep higher and higher as the revs increase?

 

normaly it boosts at 9 psi but at about 5kish it will sputter and over boost to 20psi when the solenoid is bluged in. But when it is unpluged then it is pritty much 100% ok as far as i can feel. im not sure about the ecu i can find out if it helps? oh and i have changed the solenoid and the map sensor. i cant understand why the weather would do that because when the car is ok wen the solenoid is not pluged in only is a problem wen it is connected??