How to avoid or solve re-occurring supercharger problems:

A supercharger, if properly cared for with regular oil changes, will give many years of trouble free service. Just like an engine, it can be made to fail by overheating, over revving, engine detonation, and poor care, which all contribute to many supercharger problems.

  • Heat: Supercharger heat related failures are the result of excessive heat, boost and/or rpm, overfilling with oil, “hot air” filter systems that pull air from inside the engine compartment, an inoperative bypass valve and low vacuum cams.
  • Hot air underhood filter kits: Some styles of hot air filters are sold deceptively as “cold air kits.” The higher inlet air temperature from heat passing over your radiator and engine is consumed by these hot air filter kits due to lack of a heat shield. Air entering your supercharger will be approximately 185°. With superchargers adding around 10 degrees for every pound of boost, a vehicle with a hot air filter and 10 pounds of boost would see a temperature of 285° versus a vehicle pulling outside air on a 80 degree day would only see 185°. This is the difference between detonation and heat damage versus making reliable power.
  • Overfilling of oil level: Overfilling a supercharger dramatically increases the oil temperature. The excessively high oil temperature (400°+) can also melt and dissolve the drive coupler which “cushions” the drive from the supercharger and harden the seals. Anyone who is melting down the coupler, needs to investigate the cause. Replacing the coupler will not solve the problem.
  • No oil or low oil levels: A lack of oil results in excess heat which turns the gears black or blue black. The gear teeth will then wear off from lack of oil. And if the heat from the gears running without oil is sufficient, the coupler can also melt and destroy gears.
  • Wrong type of oil: Always use the correct supercharger oil in a gear drive supercharger. Never use transmission, hydraulic, aircraft, or engine oil in your supercharger unless instructed to by the manufacturer. This can cause premature seal softening, coupler softening, oil foaming, and higher oil temperatures. JB Performance oil is compatible with all supercharger drive types except for friction drive superchargers.
  • Contamination: Be sure to keep dirt and debris away from the supercharger at all times. Debris as small as a piece of sand can cause major problems. Be sure to clean gasket areas away from where it can enter the intake track. Allow gasket material to cure the correct amount of time before starting vehicle. Use of silicones requires 12 to 24 hours to cure to prevent ‘sucking’ into the supercharger or ‘blowing out’.
  • Blow By: Oil blow by problems can recirculate through PCV systems as well as be caused by engine detonation, or worn/damaged rings.
  • Race applications and or severe use: High rpm or high boost racing conditions always create more heat in any supercharger. A sign is that only the front (hottest) area of the rotors will be scored. Also, the air is hottest at the front of the supercharger. Scuffing the full length of the rotors indicates LOTS OF HEAT from oil, boost, rpm or inoperative bypass valve.
  • Detonation: Aggressive tunes, poorly maintained engines, wrong fuel types, no tune, and more can all lead to early supercharger failure. Twin screw and roots style are more prone to failure from engine detonation. ALWAYS have a proper tune on your vehicle.
  • RPM: Exceeding the maximum supercharger RPM will lead to early failure of components, excess heat and possibly the inability to rebuild the supercharger. Just because the supercharger can deliver 1-3 pounds of more boost, does not mean it is delivering more volume of air. Hotter air takes up more space than cooler air which provides one with the impression that there is more boost when in fact the air density volume may be the same. Rotor flex and impeller flex damage can occur.
  • Nonfunctioning or disconnected bypass valve: The bypass valve lowers the supercharger temperature at idle and part throttle/cruise. The supercharger will run hotter at idle, cruise and all non-boost conditions if the bypass is disconnected. Never allow a tuner to disconnect the valve for higher HP readings on the dyno. Periodically check operation of the bypass valve. Always check the vacuum/boost control line to the bypass valve for leaks. Use zip ties to clamp small vacuum lines in place. The valve will be “open” at idle (vacuum) and close under boost (pressure). Bypass valves should always be connected to the intake side of a supercharger. The vacuum side of a bypass valve should never be connected to a vacuum line that will see boost pressure!
  • Low vacuum cams or lengthy valve overlap: Low vacuum cams can cause loss of bypass function. For low vacuum cams, JBP offers different types of bypass valves that are fully open at 5” vs. 14”. Cams with lengthy valve overlap can cause low boost numbers and hot exhaust temperatures.
  • Incorrect internal supercharger parts: Use of incorrect replacement components can lead to early component failure or engine damage. Bearings and seals must be rated for the correct RPM, heat, load, and component materials. Failure to comply will result in supercharger damage and even possibly engine damage.
  • Belt tension: Let’s face it. Belt slip can be a common problem with a supercharger. Twin screw or roots style models are more prone to belt slip due to the higher rotational weight inside these units. Adding more belt tension to an already tight belt puts more stress on the bearings within the drive snout or supercharger. It can lead to early failure of the supporting bearing. If belt slip is occurring, always check belt wear first. Gates has a free tool that they can send you for checking belt wear. Always use a belt tension tool to check tension. Using the internet method of grab and twist half turn is a sure way to damage the input shaft bearings.
  • Poorly made supercharger pulley: Aftermarket supercharger pulleys with incorrect v-groove channels will accelerate belt wear and increase belt slip. Check shaft and keyway size for fitment issues as well.
  • Incorrect installation of pulleys: Never use an impact wrench to remove a pulley bolt or hub. It will knock the timing off of the rotors on twin screw and roots style superchargers. There are special tools to remove pulleys. We have also seen many cases where pulley bolts are too long on pulley hubs and hit drive snout housings. Never hammer a keyway pulley into place. If a keyway pulley will not slide on, something is not machined correctly or is damaged on the shaft.
  • Cold temperatures: When temperatures are below 25 degrees F, always allow the supercharger to warm up 2 to 3 minutes before wide open throttle. This allows tolerances of bearing and seals to set in properly.
  • Blown motor: If you have blown your motor, your supercharger and intercooler can trap debris. Your supercharger should be inspected for damage and the intercooler should be thoroughly cleaned with a visible inspection of all fins for debris. You wouldn’t put a dirty intake back on a new motor, so why would you put a supercharger holding engine debris back on