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Many of our customers use their trucks with the TRD Supercharger for off road desert racing.  We were asked by them to come up with a solution for the chronic problem of the supercharger belts breaking in this racing venue.

URD investigated this problem and what we discovered why the belts where breaking at an alarming rate.  What is happening is that when the rear tires leave the dirt at full throttle they spin up rapidly and so does the engine, then when the tires make contact again the suddenly slow down. 

When the tires are in the air the supercharger is sped up to a very high RPM, much faster than the engine's speed.  The supercharger rotors have a lot of mass and store energy like a flywheel.  When the engine suddenly slows down the supercharger is still spinning very fast.  This pulls the slack side of the supercharger belt tight and pulls the spring loaded tensioner out to its full extension.  The next thing that happens is that the engine speeds up again and speeds up the supercharger and the spring loaded tensioner cannot react fast enough to keep tension on the slack side of the supercharger belt.  This allows the belt to lose contact with the tensioner pulley and the belt rolls off the side of the pulley and gets trapped between the pulley and the tensioner arm and locks the belt.  Engine torque now snaps the belt and boost as well as the race is lost.

The key to fixing this problem was to keep the belt from rolling off the side of the tensioner pulley.  The simple fix was to develop a pulley with tall ears on it to prevent the belt from rolling off the side it and getting locked.

The URD Tensioner pulley for the TRD 5VZ-FE Supercharger system has tall ears on each side to keep the belt on the pulley in racing conditions.  The URD pulley solves the chronic belt breakage problem in off road racing.

You do not have to be an off road racer to install this upgraded pulley.  Most off our customers that install them don't even drive their trucks off road. 

The pulley is finished in URD red anodizing to match the other SuperGrip performance pulleys that are available and looks very nice under your hood.