CTS-eV3 is a Lego replica of the 2010 Cadillac CTS-V. With Rear Wheel Drive, lots of speed, and more than adequate torque, this motorized creation is like the real car. Having been over half a year in the making, there has been many trial-and-errors (including chassis, drivetrain, and exterior redesigns). But I am quite satisfied with the final outcome! CTS-eV3 has a 4.5:1 gear ratio (minus the differential), accomplished by driving a 36 tooth gear meshed with an 8 tooth gear in a unique setup. Actual speed is a few tenths under 4 Kph! This two door coupe has been relatively replicated, including the visible V8 piston engine along with the Corvette inspired supercharger!
CTS-eV3’s drivetrain consists of two Large Motors and one Medium motor. The Medium Motor drives the steering (it is programmed return-to-center), and the two Large Motors drive the rear wheels. Motor B drives forward at 100% while Motor C drives backward at 100%. Perpendicular knob gears are used to transfer drive to the main knob gear on the driveshaft. At the opposite end of the driveshaft is a 20 tooth gear. The 20 tooth gear drives the differential, which apportions appropriate axle speeds to each side. Connected to the half-shafts of the 28 tooth differential housing are two 36 tooth gears on each side. These 36 tooth gears drive an 8 tooth gear via a unique setup (and follows Technic geometry). This results in a 4.5:1 gear ratio; the differential meshed with the 20 tooth accounts for a 1:1.4 gear reduction. The final gear ratio ends up being approximately 3.2:1, which is quicker than even a 3:1 setup minus a differential. This causes CTS-eV3 to have some serious speed while at the same time torque not being an issue.
Since this is a replica, it only makes sense to capture the spirit of the actual car. Here are some resemblances of both, starting with the headlights. I recreated the iconic shape, making sure to include the halo projector (light-blue 1×1 round transparent piece). It isn’t perfect, and the front angle is a bit too blocky, I must admit. However, this is LEGO 🙂
I had to create some complex shapes to get this part as close as possibly correct, and I like how it turned out. I used cross blocks and angle connectors to get the fog light respectably in the fascia where it is noticeable. The grilles were recreated using the intake pieces from the 42000 Technic Grand Prix Racer. The Caddy badge has been proudly replaced by a LEGO badge 😉