Sizing and Placement of Components

After most of the cuts on the chassis were made and the differential assembly was ready, the team proceeded to make some rough mock-ups of the motor and inverter.






After the electric motor was delivered, a mock-up of the coupling between the differential and the motor was placed between them.

(Christophe take another look at the assembly)

The differential coupling was designed with simplicity in mind. After the mock-up was built in a CNC router, the stress analysis was executed and the piece outsourced to a nearby professional machine shop.

Differential Assembly

The original Haldex LSD of the TT was removed from the powertrain since it was not designed to handle the high torque of the electric motor (more than twice) and the final gear ratio was too high for out single-gear powertrain.

(Original differential of the TT Quattro)

After some careful research (based on a simulation done at the laboratory), we knew we needed a differential capable of handling up to 500 lb-ft with a final gear ratio between 3:1 to 3.2:1. It turns out that a 1998 BMW E32 differential suited our needs.

(BMW differential placed inside of the subframe)

Since the differential had to be placed at an angle, the top bar of the subframe assembly was trimmed, and a new rear support was made.



A stress analysis (Von Mises) for worst-case-scenario was performed and proved well below the maximum strength of the steel.

First Cuts on the Chassis

Once the car was moved to an area where hot work was permitted, the first cuts to remove some of the sheet metal in the trunk compartment were done.


Look at Christophe (gray t-shirt)... he knew there was no ticket back once the first cut was made...



After the spare-tire well was cut, some rough markings indicated the areas to be trimmed. Caution was taken so no parts of the shell affecting the subframe supports (or any other important structural items) were unnecessarily cut.


(we also made a cardboard mock-up of the AC motor and inverter)

(Peter making a cut with the grinding wheel)

(Keith making some fire)