heres what I read tho on ka-t.org about the same concept and what some one posted about it....any one have any arguements against what he is saying?
"a centrifugal blower builds boost exponentially based on the speed of the turbine. You have to determine your max boost level at redline and set the pulley size accordingly. Since boost builds exponentially you end up with little boost or none at idle, maybe a little bit in the mid range, and a whole bunch at redline. The turbo has the impeller speed independent of the motor speed so it can spool up to max boost relatively quickly at low rpms and then stay at max boost with regulation from the wastegate. This is actually the only real advantage that a turbo has over a supercharger. So with the centrifugal supercahrger you still have the parasitic drag of the supercharger but you also have a lot of lag because it can't make full boost until redline. The worst of both worlds. With a roots style blower you have instant boost with no lag and theoretically a wider power band with more area under the curve. A roots blower does have parasitic loss but that could be argued as close to equal with the power loss from the turbo's exhaust restriction." -----I just dont understand then why people use a centrafugial supercharger if what hes saying is right.......on another note, could you use a small turbo to create boost at low rpm till the SC had time to creat more boost? do a twincharged type of deal.