Originally Posted by Gary B
Todays dual ball-bearing turbos spool up crazy fast! You ever ride a turbo Hayabusa with over 500rwhp? Ain't much lag there!!! I bet you'll have positive boost before 2000 rpm.
Turbo's have come a long way in design. Along with ball-bearings, Variable geometry Turbo's utilise a set of vanes in the exhaust housing to maintain a constant gas velocity across the turbine, the same kind of control as used on power plant turbines. These turbochargers have minimal amount of lag, have a low boost threshold (with full boost as low as 1,500 rpm
), and are efficient at higher engine speeds (they are designed to operate in its optimum A/R Ratio at any RPM). In many configurations, VGTs do not even require a wastegate.