Project Professional Awesome Time Attack Evo: Part 4 – Drivetrain
Today, boys and girls, we’re heading back into the technical side of the Professional Awesome Evo. For your reading and viewing pleasure, we’ll be showing all the secrets in the drivetrain of the fastest Limited Class time attack machine ever to compete at Buttonwillow Raceway.
When we had the Evo VII chassis, we started with the standard AYC (Active Yaw Control) rear differential and ACD (Active Center Differential) that came with the car originally, but after regularly having complications with various pumps and electronics, we decided to switch to the mechanical setup offered in the early years of USDM Evos. For us, this consists of the Wavetrac front differential we’ve had for some time, the standard OEM viscous center differential and the OEM, clutch type, rear differential. Since the switch, we couldn’t be happier with the reliability of the drivetrain and the balance it helps give the car. Diving into what puts the power to the ground, we’ll start with the clutch, head to the transmission, stop at the transfer case and work our way back to the differential.
The clutch is a special unit made for us by the fine folks at Exedy Racing Clutch USA. We had been running an off the shelf triple solid disc cerametallic unit that was purchased in a pinch many years ago. This clutch worked flawlessly for us, but we didn’t need a clutch with a capability of holding 923 wheel torques. Due to the massive load this clutch could handle, it also weighed more than needed and could potentially apply more stress during shifts than a twin disc.