So full built 3.5 ecoboost with 6758 efr turbos got a base tune on it runs fine till about 10 lbs of boost then goes crazy. Like the wastegates and blow off valve start going off. Thought maybe something with boost controller so I put some extra springs I had in actuators to 26lbs and it went a little higher but same symptoms. Anyone got anything they can think to check?

 

Has it ever ran over 10lbs withut an issue?

 

It's a new build everything is new/different. The stock motor and upgrades I was peaking 22 lbs. It's a full forged short block with ported heads and a freak o boost full race kit now with 6758 efr BorgWarners. Full fuel system everything is done. Runs great at idle as far as motor everything seems great till it tries to build boost.

 

Who set up the tune for it? Sounds like it may be hitting a limit in the tune.

 

I was thinking something in the tune but I don't know what the computer could use to make it happen when I disabled electronic control over the boost and it still does it. And I didn't see any massive change in the afr. But I'm going to get my water meth injection installed then take it to a different tuner where they actually build cars. The last guy I took it to only does tuning. So I guess I'm just gonna have to wait and see what happens when I take it to them. I was hoping to get it running right first so I could get it broke in good and change the oil.

 

If this is a stock PCM deal there are a number of things in the PCM that need to be changed. This could be something mechanical as well, but it sounds like verifying the tune is a good place to start.