won't hold more than 14psi

[Jdizzle659]

I have an 07 mazdaspeed 3 and I can't get it to hit more than 14psi on any tune. 0.0 knock, afrs running high 12's(usually high 11's to low 12's)
Mods: Cobb Short Ram, Cobb Inlet Pipe, Tubular Turbo Manifold, TurboXS Downpipe (Catless), Test Pipe (Catless), Custom 3inch cat-back, Rebuilt Fuel Pump, Meth injectors, Spec Cluthc Kit Stage 3+, and Fidanza Lightweight Flywheel

Assuming there is no boost leak, what should I look for?

 

[AutoEuphoria]

Find the boost control solenoid and disconnect it. Then take it out for another spin and see if you notice anything different. If not, the solenoid is probably done for.

The solenoid can be found by locating your wastegate (back of the engine compartment) and tracing the vacuum line coming out from the top. It should go to a small black part that would have another vacuum line going to/coming from it as well (this one goes to the intake).

This would be my first guess. 14psi sounds about right for a free-flowing motor (intake, manifold, catless DP/MP) with a non-functioning BCS. I think in stock form things max out at about 10-12psi with that solenoid unplugged/not working.

 

[Jdizzle659]

Find the boost control solenoid and disconnect it. Then take it out for another spin and see if you notice anything different. If not, the solenoid is probably done for.

The solenoid can be found by locating your wastegate (back of the engine compartment) and tracing the vacuum line coming out from the top. It should go to a small black part that would have another vacuum line going to/coming from it as well (this one goes to the intake).

This would be my first guess. 14psi sounds about right for a free-flowing motor (intake, manifold, catless DP/MP) with a non-functioning BCS. I think in stock form things max out at about 10-12psi with that solenoid unplugged/not working.

Thank you. Will definitly try this and update tonight

 

[Jdizzle659]

Find the boost control solenoid and disconnect it. Then take it out for another spin and see if you notice anything different. If not, the solenoid is probably done for.

The solenoid can be found by locating your wastegate (back of the engine compartment) and tracing the vacuum line coming out from the top. It should go to a small black part that would have another vacuum line going to/coming from it as well (this one goes to the intake).

This would be my first guess. 14psi sounds about right for a free-flowing motor (intake, manifold, catless DP/MP) with a non-functioning BCS. I think in stock form things max out at about 10-12psi with that solenoid unplugged/not working.

I unplugged the solenoid and the boost acted the same, so i replaced it with a manual boost controller but even with the manual on i can't get it to hold more than 14psi... i've already done a boost leak test and i'm not leaking.

 

[moll88]

Check ur wastegate function on ur ap if it's maxing out rapidly ur WG maybe doomed just a thought

 

[AutoEuphoria]

Well, I'm not sure then, sorry...could have sworn that would be the cause.

 

[Darth Vader]

Sounds to me like your wastegate actuator has a leak and the spring is giving you boost control.

 

[mortimersnerd]

This is likely a dumb question, but isn't clarified in your original post. Is this a change, or have you just now been able to measure it? I ask because I live in Denver and 14psi is pretty good here at 5500 feet. Not sure if this would impact you.