JR Boost Upgrade Kit, :: 90-91 1.6 no PS no AC up to VIN#209445

The Jackson Racing Boost Upgrade gives your supercharged Miata a healthy shot of adrenaline! By spinning the supercharger faster, boost pressure is increased. The result is up to a 15-20% increase in horsepower and torque! All kits include boost crank pulley, high flow fuel pump and belt. 90-93 kits include additional fuel management electronics. 90-91 1.6 no PS no AC up to VIN#209445