After it became very clear that the boost tapered off poorly the next course of action was a boost controller and also to check the condition of the factory Fuel Pump
Below is a statement by Martin Musial of AMS (President, Head tuner and Engineer)
"Well we quickly bypassed the factory boost control system, which oddly enough has two boost control solenoids. We set boost to peak at the same factory level of 22psi but this time it held to 16-17psi at redline. Peak power now climbed to 265-270whp, that’s more like it! So now we’re holding roughly the same boost or 1psi more than an EVO IX and we’re making 10-15whp more, looking good"
While we were tearing things apart we thought it would be a good idea to test the limits of the stock EVO X Fuel Pump
Again a statement from Martin:
"We pulled the fuel pump and threw it on fuel pump test rig. Running the voltage supply at 12V and then 14V we measured flow rates at various pressures, from 40psi up to 100psi. The results where a little surprising as the stock EVO X fuel pump flows about 15%-20% more than a stock EVO IX pump. Depending on what the stock injectors are rated at the EVO X could have a stock fuel system that is capable of handling over 350whp."
Stay tuned guys, we are not slowing down anytime soon LOL
Eric
Below is a statement by Martin Musial of AMS (President, Head tuner and Engineer)
"Well we quickly bypassed the factory boost control system, which oddly enough has two boost control solenoids. We set boost to peak at the same factory level of 22psi but this time it held to 16-17psi at redline. Peak power now climbed to 265-270whp, that’s more like it! So now we’re holding roughly the same boost or 1psi more than an EVO IX and we’re making 10-15whp more, looking good"

While we were tearing things apart we thought it would be a good idea to test the limits of the stock EVO X Fuel Pump
Again a statement from Martin:
"We pulled the fuel pump and threw it on fuel pump test rig. Running the voltage supply at 12V and then 14V we measured flow rates at various pressures, from 40psi up to 100psi. The results where a little surprising as the stock EVO X fuel pump flows about 15%-20% more than a stock EVO IX pump. Depending on what the stock injectors are rated at the EVO X could have a stock fuel system that is capable of handling over 350whp."
Stay tuned guys, we are not slowing down anytime soon LOL
Eric