just recently I've been having this problem with the car that wasn't there before .. i accelerate, boost builds, full boost is achieved, RPMs climb, no CELs ... and then ... car almost stalls, losses all its momentum and engine feels like I'm applying the brakes .. ?!!? .. I let go of the pedal, throw it in neutral and pull over, pop the hood, check things over, all vacuum lines still connected, boost controller line is not torn or melted, everything checks out good under the hood.
So I do it again, and the same thing happens, but this time I let go of the pedal for 2 seconds while still in gear and then punch it again and now it accelerates fine towards redline. This happens off and on.

Is there any chance that I keep hitting boost cut ? .. external wastegate and its vacuum line and source all check out good and in order .. what else could this be ??

no CELs, oil pressure good, fuel pressure good, plugs and wires good, tuned on 93 octane and running 93 octane ..

 

Sounds like your hitting boost cut. What kind of tuning software are you using?

 

Crome Pro

 

sounds like he has a stock map sensor and its reading to much boost

 

Does it sound a bit like bouncing off the rev limiter or speed limiter once? Or does it sound like the brakes are being hit while still having the gas pressed?

 

I'm boosting 14psi on a GM 3-Bar MAP.

^ yes, almost like the brakes are being applied while I still have the gas pressed .. no bouncing of rev limiter

 

I would bet money it's fuel starvation. I had the same problem a couple years ago and I couldn't figure it out for the life of me. My fuel pump would prime and all just like normal but it wasnt working to capacity. I replaced the pump, which was a walboro 255, and it ran perfectly!