Need Help!! Turbo guys

[jassoom55]

Hey guys

I have an EDP Turbo kit with MPR Built engine, L&M Custom cams, earlier today the car was on the dyno being tuned. the wastage's has the 10psi springs in it and G-force boost controller but for some reason when it reaches 5k rpm the boost just drops rapidly to 4-5PSI. I could not make any numbers or power either, we tried 15psi also same on 5k RPM the car just start to drop boost to 4-5PSI. for example I have the 10PSI springs it reaches the 10psi but as soon as it hits 5k or so RPM it start dropping boost. we could not continue tuning it because it was doing the same thing over and over, did more than 8 pulls tweaks in between.. nothing. any thoughts what that would be? or what's the problem here?

 

[hitmix300]

My boost controller is the same one and it's very flakey. I have tried multiple plumbing setups for it and it still doesn't work properly. Currently i am just running spring pressure and using the gforce as a gauge lol

 

[usmc320]

Try unhooking the boost controller so only the wastegate spring has control. Then try making a pull again. That will tell you for sure whether its a boost controller issue or something else.

 

[CPRsm]

Boost drop is not abnormal on a coyote. It will drop a few psi, but be pretty constistant. So if it drops 2, you can set it for 10 and it will drop to 10. 12 drop to 10, etc. It's back pressure that causes it. So the drop will increase slightly as boost goes up, and back pressure follows. But if you raise the boost more and more and it falls to the same boost level, that tells you you have a flow restriction somewhere that's keeping boost down.

 

[jassoom55]

Yes the boost is reaching up to to 10 and then drops to 4. we increased that to 15 and still drops to 4-5... I have no idea whats going on, I'm going to try remove the boost controller and see what happens tonight.

 

[CPRsm]

Just turn it off or duty cycle to 0. Won't tell you too much w this problem.

 

[jassoom55]

Im getting crazy over here, I have tried to unhook the boost controller, same thing, I changed the wastage springs to 12psi and run the turbo on wastage, same thing is happening. WHAT COULD IT BE, I'm loosing my mind here.