Boost problems

[snipersixx]

Anyone here having problems controlling boost, I have been fighting to keep boost down I have a precision 70 gtq turbo with a heavy duty adjustable actuator. Just can't seem to keep the boost down below 30lbs. I've tried adjusting the arm on actuator longer no change. Anybody have this kind of thing happen to them and how to fix it ?????

 

[2QUIK6]

Wow can't control it below 30#!! This is still using the stock internal wastegate? What size is the WG hole in the exhaust side housing?
I had a similar problem, but I couldn't control it below 20# on a PT6131. WG hole was 1 1/8", so I openened it up to the max I could with the 1 3/8" puck size that was in my THDP, with only about 1/16" of an inch left I also put a smooth radius curve on the inside of the exhaust housing around the WG hole to better the airflow exiting the WG, and now it works like a charm down to 13#.

 

[snipersixx]

Originally posted by 2QUIK6
Wow can't control it below 30#!! This is still using the stock internal wastegate? What size is the WG hole in the exhaust side housing?
I had a similar problem, but I couldn't control it below 20# on a PT6131. WG hole was 1 1/8", so I openened it up to the max I could with the 1 3/8" puck size that was in my THDP, with only about 1/16" of an inch left I also put a smooth radius curve on the inside of the exhaust housing around the WG hole to better the airflow exiting the WG, and now it works like a charm down to 13#.

I did that first when I recieved the 3.0 thpd I guess I may be the only one with problem. Just can't under stand why there is not more people with same problem.

Anyone have any clue to stop this.

 

[snipersixx]

One more thing is it because I have heavy duty actuator with a 18 lb. spring.

 

[azgn]

sounds like your wastegate is stuck/binding...I ASSume you are just looping the wastegate and actuator and not using the stock solenoid?

 

[2QUIK6]

Try running tuner-style as Woody suggests, just run a vac hose from the actuator to the compressor side of turbo to remove any boost controller or solenoid, this should make the max boost psi the same as the spring tension in the actuator, a HD WG actuator is 18#. If your boost climbs above that with the rod out all the way then something is binding or the WG hole still is not big enough. Most recommend to open it up to 15/16", but the THDP puck is 1 3/8", so if you only opened it up to 15/16" there is still plenty of room left.