488 GTB stage 3 after 6500rpm problem

Hello everyone


I have a 488 with hybrid turbos and a full exhaust system. It’s tuned to 1.6 bar.

Up to 1.3 bar, the car accelerates smoothly all the way to the rev limiter. However, when boosting higher, from 4th gear and above, after 6500 RPM, I hear a whooshing sound as if it’s losing pressure, and both power and boost drop—the boost gauge falls to 1.4-1.5 bar, and after a gear change, it drops even further. I have to let off the throttle and reapply it to regain power.

I’ve pressure-tested the system, and there’s no boost leak. I’ve replaced the solenoids with brand-new OEM ones, and I’ve also checked the vacuum system—everything seems fine.

I attached and a video.

Does anyone know what could be causing this issue?

 

Yes both of them…

 

Yes stock ECU with tuning

 

The boost pressure limits have increased with the ECU program. To clarify, the ECU provides 100% duty cycle after 6500 RPM..

 

Yes, without any pressure loss. The entire circuit has been pressurized to 3 bar.