Many builders choose a Lotus vehicle as a great foundation for a build because of its lightweight construction and great handling characteristics. The owner of this project was thinking the same thing when building his own amazing track day car.
The project started in April 2014 when the owner was looking at a Mk1 Esprit with an engine failure. The plan was going to swap the engine out for an Audi V8, Chevy V8, or a turbo V6 but after realizing the cost and weight the plan changed. The owner then found what he was looking for in a Lotus Exige S1 which was almost 700 lbs lighter than the Esprit.
Once the car was home it went through the process of completely stripping it down. One really nice thing the owner did was weigh everything that came off the car and published those weights on his website. A lot of people starting a project like this always want to know how much something weighs for possible weight reduction.
The owner never set out to purchase a Ferrari engine. Instead he had set a power-to-weight ratio he wanted to obtain and the Ferrari engine came up for sale at the right time. He purchased a 3.5 L F355 V8 that had already gone through a race prep and had previously powering a single seat race car. The engine came with a PACE six-stage dry sump system, flat plane crank, 5 valves per cylinder, titanium rods, and produced 380 horsepower and an incredible sounds at 8,250 rpm.
Before installing the drivetrain the owner modeled everything in CAD. Here he laid out everything such as the engine, transmission, and the subframe supports. After everything was completed he found out his CAD designs were within +/- 5mm. He even used CAD to design the custom aluminum 34 liter fuel tank.
The rest of the drivetrain consists of a F355 transaxle controlled by a shifter with an aftermarket “slick-shift” open gate. This changes the gear shift shaft angle from 30 degrees to 51 degrees. Driveshafts were custom made by Mac Props with 108 mm Lobro inner CVs and 28 spline Astra outer CVs.
Other interesting modifications were exhaust headers made from BMW E92 M3 V8 headers, dry sump tank made from an Audi A8 air suspension canister, Cosworth Pi Omega D1 digital dash, and a CNC machined support from billet 7075 aluminum.
The project is nearing completion and only needs a few things before it can start singing its wonderful melody around the track.
Source: S1Elige (s1elige.blogspot.fr URL no longer valid) via ESD reader Ben