I think the older stage one kits had a flaw in the intake piping ....too much restriction to the supercharger and not getting over 8 lbs regardless of pulley size. If that's the case the 90mm will be more matched to the charger. The smaller ones may be spinning the charger but the restriction is choking it out through ing the tune off ... the flaw was corrected by new filter location straight back close the transmission the old design location was 2 filters in the front left area with 90 degree bends ......where are yours located?
|