Hello friends!!

I have a little question. My turbo is working at 1.35-1.4 bar.(with stage 4 FC) At that pressure should be adjusted wastegate actuator , 0.8 ,0.9 or 1 bar? the turbo is a journal bearing gt2871

All depends what you want your base opening pressure to be without a boost controller switched off. If you don't have any boost controller and the actuator is connected straight to the boost source then the preload has to be set to the desired boost as possible but I doubt that is the case, and that you have an actuator as strong. Remember to set it in 4th gear at full engine load. However, I bet that you do have some sort of a boost controller either MBC or EBC. In this case the controller can double the the opening pressure by venting some of it to the air, cheating the actuator, to allow you hit your desired boost levels. So, in theory it can be set to as low as 0.7b, thou, you need to verify it on the road. Personally, I would set it up as close to the desired boost as possible leaving some overhead and let the MBC or EBC so its job. Otherwise you might experience some nasty boost spikes.

if I have a MBC .

the turbo is working to 1.35bar . So, if I set the wastegate 0.8 - 0.9bar , would be no problem ?

What benefits would have an actuator 1 or 1.1bar or more?

With stronger actuator you have less chances of dropping or fluctuating boost. For your turbo I would go with 1b actuator and set the preload to about 0.8b.

I don't know if 0.8b won't be a problem with your current actuator. Do you know its max preload pressure?

PS - when you will change the preload to a higher value remember to adjust the MBC or you will be boosting over the efficiency of the turbo and or blowing more air, and you will fccuk up the AFR.

my actuator begins to open up to 0.9 bar , then it takes almost 2 bar to open at all.

This is a proper fit ?

It makes no sense at all. Do you have a Chinese gt2871 and so you are using the actuator that came with it? Most likely it is 1 bar like it was in my case. Set it to 0.8b, adjust the MBC and forget.

Having said that, why would you want to mess with it if you got it mapped by Leighton? If you make changes then most likely whole map will require tweaking.

mainly because I have never verified , and wanted to know what was the right fit.

Thank you very much deannn_20vt

although I'll try it on the road, to really know what pressure opens the actuator and tell

Don't forget to turn your MBC all the way down to verify the actuator opening pressure,

I finally set the actuator to 1 bar . Thanks for everything