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Eaton M90 MP90 supercharger rebuild and modification


This is another custom project we did for a local customer. We modified an Eaton MP90 supercharger designed to fit a Toyota Tundra and machined it to fit a Lexus LS430 3UZ-FE V8 engine. The supercharger snout was too long for proper alignment of the belt drive system. The original TRD pulley was 2.3 inch diameter and too small for the boost pressure desired by customer. Customer wanted a boost threshold of 6psi. Using factory LS430 crankshaft pulley dimensions it was calculated that a 2.9 inch supercharger pulley will provide 5.9psi boost pressure. We chose to install a quick change supercharger pulley. This eliminated the need for custom pulley puller and allows for fast changes in boost pressure with a simple pulley replacement.

Supercharger was disassembled and all components inspected for wear and evaluated for replacement. Supercharger snout was welded to fill in an indent in the casting. This casting indent/dimple is not present on most Eaton M90 or MP90 superchargers. Great care was taken to ensure proper welding penetration as well as heat dissipation to ensure minimal component warping. Coaxial alignment of the bearing seating area is critical for supercharger performance. All component machining operations were performed using a lathe. Special fixture was made to ensure snout alignment during machining. Input shaft was shortened in the lathe ensuring all critical bearing and pulley seating areas remained accurate size and coaxial.



  1. Shorten supercharger snout
  2. Determine proper pulley size requirement for 6psi boost  pressure threshold
  1. Supercharger disassembly, component cleaning, and inspection. Bearings, seals, input shaft, and drive coupler inspected for wear and component replacement determined
  2. Supercharger snout and input shaft precisely measured and blueprints compiled
  3. Supercharger snout welded to remove casting indent
  4. Machining fixture made to mount snout
  5. Supercharger shout shortened as per instruction
  6. Supercharger input shaft shorted
  7. Dimensions verified after machining
  8. Snout reassembled
  9. New, low drag, supercharger seal installed
  10. Quick change pulley hub pressed onto the input shaft
  11. Supercharger reassembled and filled with fluid
Compilation of pictures before, during, and after machining modifications:

7 thoughts on “Eaton M90 MP90 supercharger rebuild and modification

  1. Hello, is this supercharger modification still available to purchase?

  2. Hello,
    We still offer similar service. Please email us at the address in the contact section for additional details.

  3. These guys did an excellent jog on this project for me! Neat to see these posted up. This custom kit was sold on Club Lexus years ago.

    I highly recommend these guys!

  4. hello i have a 01 lexus gs430 3uz fe want to add a super charger kit. same engine as the one you did on ls430. please let me know if you guys can custom make me one or if you can provide same parts that where custom made to make that kit work please let me know thanks

  5. Hello Ryan,
    We did this supercharger modification originally in 2011 on a kit made by a company that does not exist anymore. Unfortunately, I do not have any other information to help you. The customer brought in the supercharger and requested these modifications. Thank you for the interest.

  6. hi, im looking for a supercharger mp 90 for an 06 tundra 4.7

  7. Hello John,
    We do not offer superchargers or kits for your vehicles. This is our overview of a special job we did for a customer with that Eaton supercharger. I’m sure you can find a reputable vendor selling a kit for your Toyota Tundra.

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