PSI 8-71 hi helix supercharger. What is a PSI roots supercharger you may ask. Well it is one of the most innovative superchargers that have come out to racers in a long time. The PSI design, which went into production in early 2007 on 8-71 units, brings added elements of performance and safety to the racing world. On all the PSI units, the front bearing housings are made of billet material that are press fit into the rotor case and use precision dowel pins and push the rotors back in the case allowing the air to come and load the front of the rotors providing a smoother transition of airflow and providing more boost and cooler air as the air does not get so beat up entering the blower. This bearing plate design increases the strength considerably over the common dowel pinned bearing housings normal to most supercharger designs. The rear cover is also captured in the same way. This design also benefits repeatability of rotor location. As these units are overhauled, the doweled design tends to wobble out the bores and the rotors find themselves misaligned over time, which can cause supercharger malfunction. This blower uses precision bearings in the rear as well as rear gears to try and help keep rotor timing more precise and give longer life between restrips and precision ball bearings in the front as well as double lipped teflon seals for superior sealing. RBS is proud to offer the newest in PSI rotor design to help give you the winning edge. The rotors also incorporate a unique feature and that is a removable plate front and rear that have multiple advantages such as teflon retention which allows for quick teflon replacement and if a rotor is to gall to a bearing plate the end plates on the rotor can be replaced and not valuable rotor length lost and lots of costly time to machine all parts to bring the blower back to spec. The rotor end plates are also stripped with nylatron adding one more spot to help seal the blower up and keep the boost down in the manifold to help make more power. Blower snout is sold seperate and length depends on application and can be had in 4 or 5 or 6in. snout lengths. This blower can be ordered in a standard 60 degree rotor or a 120 degree hi helix rotor depending on the use. RBS can help the customer choose the best supercharger for your application. Please note magnesium cases are available at an additional cost and the purchase of a PSI shipping crate is required at purchase of supercharger. BLOWER WITH BLOWER SNOUT WEIGHTS 90 POUNDS.