Non A*E* Roots Numbers

[Walter Sherwin]

>One of the more significant things to observe in the numbers posted here is
>how LOW the VE for a Roots is at low engine/blower speed--these low VE
>numbers at low speed translate to not much boost there until the revs are
>up a bit!! A VATN turbo will actually get the boost up a LOT SOONER than a
>Roots or a Screw huffer!! Get it up rates for VATN turbo/
>Roots/conventional turbo are prolly sorta comparable to the same rates for
>a 15 year old boy/ 30 year old man/50 year old man!
>
>Another point to consider--Don't even THINK about running a Roots or a
>screw in "blow thru" configuration!





I agree completely with your comments regarding the "Roots" blowers.   On
the other hand, "Screw" compressor technology has come a long way over the
years.  You might be surprised by the performance figures for an optimized
screw unit, no matter whether you want to examine  1)Dry Discharge
Temperature   2)Adiabatic Efficiency   3)Volumetric Efficiency   4)Parasitic
Power   5)Internal Compression Ratio...........etc.  Sized correctly,  a
screw(s) can nearly match the peak efficiency of a good turbo system, but do
so over a much broader range, with near instant response (wet or dry).

Do you have a URL for the VATN turbos?



Walt.