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Talking Drag Racing Transmission Technology With Stanley Poff

With multiple competition-level transmissions and countless aftermarket drivetrain essentials in the company’s product line, TCI is at the forefront of drag racing transmission technology. Both the Powerglide and TH400 transmission from TCI have established themselves as the benchmarks in competitive drag racing. Each transmission, however, is best suited to specific applications.

The GM Powerglide is 29 ½ inches long; it weighs between 95 and 115 pounds when built in the OE stock case and its reciprocating weight takes about 18-20 horsepower to operate depending on the components installed. As a result, the Powerglide is more commonly used in lighter race cars and in applications where traction can pose a problem due to limitations in tires and suspension when compared to power. TCI also suggests that any car making over 1200-1500 horsepower utilize an aftermarket case. If not, the OE bellhousing and rear piston portions of the case can be over stressed and fail. The 1.82 OE planetary has a limit of about 500 horsepower, while the 1.76 in the OE carrier can manage 600 to 700 horsepower.

The GM TH400 is 31 ¼ inches long, weighs between 140 and 150 pounds, and takes about 32-36 horsepower to operate depending on components installed. The TH400 is best suited for heavier race cars, those that have substantial traction capability and those that need an extra gear to keep a narrow power band more in sync.

The aftermarket components for each transmission are made of higher grade materials and increase both friction and steel clutch capacity to hold more horsepower. The weight variations in the aftermarket components are little to none, and sometimes even weigh less, thereby cutting down on horsepower consumption.

Furthermore, lightweight aluminum drums, planetary and die cast pans all are used in order to reduce weight without compromising strength in drag racing transmissions from TCI. While these components require a little extra maintenance, they are crucial in reducing weight. TCI also takes special care to make sure friction and steel clutches release properly and do not drag.

Many of the heavy-duty gear sets and shafts are made from 9310 and VASCO materials, both of which belong to the vaccumelt family of metals. VASCO materials come in various grades, with some being better for gear purposes and others best suited for input shaft. TCI engineers choose the best material for each individual piece.

Where drag racing transmission fluid is concerned, the frequency of change is all relative to heat. Engineers at TCI tell customers that it’s always best to run a temperature gauge. If the transmission temperature is staying between 160 and 180 degrees Fahrenheit, TCI recommends that the fluid be changed every 40 to 50 passes. If at the end of a run the transmission reaches the 200 to 230 degree mark, measures should be taken to reduce temperature and fluid changes must be more frequent.

In applications where the transmission temperature stays low, a thinner fluid can be utilized. Racers competing in Stock, Super Stock, and Comp Eliminator classes will use thinner fluids for ET purposes. However, a thicker fluid needs to be used when temperatures run high. Big horsepower engines with automatic transmissions, some of which produce 3200+ horsepower, usually run thicker fluids. MAX SHIFT™ transmission fluids from TCI are available in several different weights and formulations that cover all applications.

TCI provides transmissions for racers of all classes and levels. Entry level bracket racers need a transmission that will leave the starting line and run the target number every time. Class racers need something with lightweight components and less reciprocating mass. The high horsepower, heads up classes provide the biggest challenge. These classes feature heavy race cars that harness 1500-3500 horsepower, all with limited tires and suspension. As a result, TCI constantly goes back to the drawing board to create the best applications for its customers.

The build your own TCI Powerglide chart provides the informed racer with the opportunity to choose all optional components for their transmission from case, pump, drum, planetary and beyond. More transmissions than ever are built completely new today, from tail shaft to input shaft.