boost....

[mpampis_]

hello my friends, i read a lot of threads but i guess i am the only one that i have this problem. recently i change my turbine because my old one was broken and i lose pressure. i tried to regulate the base pressure (the old one was about 0,45 bars) but after 5000 rpms the boost is rising to 1,5 bar that it is a lot. i tried to change the wastegate with the garret's one that my old turbo had but the same problem, after 5000 rpms i have hign boost. i am ragulating the base pressure by connecting turbo and wastegate together as i did in the past, just for regulating the base pressure. Any idea please? it is like the wastegate, can't decrease all this pressure

[AlfaJack]

You may need to use a manual boost controller - are you using the standard electronic pier-burg valve?

[mpampis_]

i'm using a boost controller, but you have to set the base boost from the wastegate first. if the wastegate is boosting up to 1,5 either you have a boost controller you can't boost less than this pressure

[jimnielsen]

if you are connecting the hoses from the WG actuator and the turbo pressure and still seeing 1.5 bar THEN the wastegate is not opening. Remove the wastegate from the car and test its opening pressure with an air compressor and a simple pressure gauge.

with the wastegate connected how you have it - the actuator is the sole controller of boost - so it needs to work. The shaft may be sticking..

jim..

[mpampis_]

When I disconnect the hose and I am pressing air direct to the wastegate I see that it is opening, tomorrow I will disconnect the wastegate and I will see it on the road. Thanks by the way guys

[jimnielsen]

yes, but at what pressure is it opening.. it is very easy to produce a lot of 'boost' with an air compressor, you need to put a pressure gauge on that line with a T piece and measure the opening pressure..

[mpampis_]

when i make bypass the turbine and the actuator i have 0,6 bars, the problem is that even in that way, after 5500 rpm the pressure rising to 1,50 bar. the only i can thing is that the wastegate can't hold the pressure and is closing the port, but i tried 2 different actuators. the stock one of the turbine, and my old one as the garrett had and i knew that after 0,45 bar stayed open. it is like the turbine can't send away the rest pressure. i will try to disconnect the wastegate today to see when the port is always opened if i have boost. the normal is to have no boost. the other think is if the solenoid of the wastegate to have a leak, so when you are boosting the wastegate is opening and because of a leak loosing pressure there and is closing again

[mpampis_]

well i guess i found the reason. i just open the cap of the turbine (exhaust side) and the hole of the port is very small to put out the gas at high rpm. tomorrow i will enlarge it and i will make a flange for enlarge the distance, so the wastegate will open the port a bit more....thank you anyway guys

[jimnielsen]

do you have any pictures of the problem and its solution?

[mpampis_]

I have not pictures but I will try to explain you. My new turbine has bolts in the end (at the place that connect the turbine and exhaust) when you put out this part there are 2 holes. The big one with the wheel and a small hole that is the wastegate taping it. This hole was 190 mm diameter and at high rpm the gas could not get out of this hole, so the boost keep rising to 1,6 bar (this turbine is made for 1,6-2,4 boost). I open this port from 190mm to 220mm and the pressure is now 0,6 bar. With the boost controller I can Boost up to 2,5 bar