TCI Circlematic Transmissions are specifically designed for use in oval track racing applications. Featured inside each transmission, you'll find high performance clutches, bands and a steel clutch hub. The Powerglide transmissions contain a modified planetary gear set. On average, lightweight Circlematic Transmissions are 50 to 60 pounds lighter than manual 4-speed transmissions, and cost $500-$600 less for a basic automatic setup. These track-tested automatic Circlematic Transmissions are more responsive off the turns, have quicker engine picks, and have excellent throttle response in corners and on restarts, resulting in consistent performance improvements over a standard 4-speed setup. This consistency eliminates the need to have the clutch adjusted before each event. Each transmission is triple tested including the valve body, static hydraulic pressure, and final dyno testing to ensure the best performance for your circle track needs.