Have you ever heard of Gear Vendors? If not, and you’re running a high-horsepower car, you should definitely check them out. Their drag racing Under/Overdrive offerings are legendary in the industry, found in the transmission tunnel of many Hot Rod Drag Week winners and competitors over the years.
The Gear Vendors Under/Overdrive is a planetary gearbox that adapts to the output shaft of your existing transmission and adds an additional 0.78:1 gear to your existing ratios. The advantages of adding the unit are many – the high gear will now have an overdrive ratio of 22 percent, but you can engage the Gear Vendors unit in any gear, allowing you to split your existing transmission ratios and doubling the number of available gears. Your three speed transmission (Turbo400, etc.) will now become a six-speed transmission, while a four-speed will become an eight-speed.
How does this help your car, you might wonder? By engaging the Gear Vendors unit, you split the current ratios and keep the engine solidly in the power band for a longer period of time. It will help to improve acceleration, drop your sixty-foot times by allowing you to run a higher rearend gear ratio, yet keep the engine from overrevving in top gear through the traps. As the unit is powered up through a 12-volt connection, installation and wiring is simple and the control switch can be mounted on the steering wheel or somewhere else within easy reach of the driver.
Another advantage is that your torque converter will not need to have nearly as much stall, keeping the car streetable if you should choose to do so. They offer units compatible with nearly any automatic transmission on the market and even most four-speed manual racing transmissions like Lenco and Jerico. The planetary design uses a cone-style clutch system, which negates parasitic loss and is incredibly efficient, losing approximately only one horsepower per 400 applied to the unit. Check out their website or give them a call and see if they can help you achieve your goals.