The OPM limited-slip is a patented clutch-type custom made limited-slip differential. We start with a stock diff and remove all the gears and shafts to inspect and clean them. Then machining of the case is performed and the clutch packs are fit. The diff is then re-assembled and a spring block is pressed between the spider gears to put pressure on the side gears.

It works extremely well and has a long operation life. We have units in use in Solo, Improved Touring, Rallye, Ice Racing and high-performance street applications.

In comparison, the Quaiffe LSD is a gear-type unit. It is heavier than the OPM unit (like a heavier flywheel) and also has to re-engage if one of the wheels loses contact with the street or racing surface.

The Phantom Grip LSD is an incomplete copy of an OPM unit. It has the spring block, but no clutches so it wears out the diff housing. Dollar for dollar, the OPM unit is your best bet.