Remember using Meth on a Centri or a Turbo is a bit different than using Meth on a TS/Roots blower. On a turbo or Centri you can spray post compressor to cool the intake air after it is compressed getting decent gains. On a TS/Roots spraying the intake system before the blower is almost totally nullified after it enters the blower and it is compressed heating the intake air back up. The only decent way to do Meth on a TS/Roots is spraying after the blower usually by installing ports in the lower intake manifold. On a TS/Roots blower E85 is really the better way to go.