(did search) in general, what do u guys mean when u say the car will die at top end with small (fast spooling) turbo's? does it mean its got a trap speed due to turbo maxing out or ....?

 

smaller turbos usually have high pressure, low flow , you want high flow

 

top end means like, top end of ur rpm band. if the turbo doesn't have "top end" it is too small and cannot provide enough air flow at high rpm's.

 

Exactly, CFM is where it is at.

..not a word. JFWY dude!

 

The whole point is to get boost, and boost only happens when the turbo is providing extra pressure.

With the motor at high rpm, the turbo must meet the motor's demand for air + more in order to create boost.

You'll know when you have too small of a turbo. The motor will work against it.. near to the point when cylinder vaccum is what's turning the compressor instead of the compressor pressuring the cylinder at high rpm.

nah, a bit exaggerated on the last note

 

Are these problems on your engine? I mean

1) Does this smaller turbo hurt your engine or

2) Do you just stop making extra power on boost and you just accelerate normally at high RPM?

 

to me it means dying at the top of your rpm band or not making power all the way to redline...