Drag Illustrated Issue 181, March / April 2023 | Page 84

PARTNER PROFILE
The Sonnax Smart-Tech Drum Module for Turbo 400 transmissions offers a multitude of benefits , including improved performance , efficiency , and safety .
THE DRUM MODULE
The concept of a redesigned system was first put into use decades ago by noted transmission guru John Kilgore , who has been credited with a number of innovations over the years . Kilgore sought to make his Superlight Turbo 400 a viable option for Stock Eliminator racers . His design and use of smaller clutches accomplished many of the same goals . Angling the design towards those particular classes perhaps limited the ultimate capability of the concept , as did the manufacturing processes and materials of the time .
Fast-forward to today and Sonnax tackled the original problem with advanced engineering and modern manufacturing . The end result — the Smart-Tech Drum Module — is a monumental step forward in both performance and safety for all levels of competitive racing .
The Smart-Tech Drum Module replaces the factory style , two-drum design with a single drum module that houses counter-rotating components that are 3.3 lbs . lighter than an aluminum twodrum design . With that reduction in weight , it is 53 percent more efficient than an aluminum drum duo , and 68 percent more than an iron

SONNAX ’ S GAME-CHANGING TH400 SMART-TECH DRUM MODULE

BY STEVE BAUR

W inning a race often comes down to just fractions of a second . The new Sonnax Smart-Tech Drum Module for Turbo 400 transmissions could be a gamechanger for racers looking for those key , incremental improvements in on-track performance , and it offers many other valuable benefits as well .

Traditionally , the Turbo 400 internals are comprised of separate iron forward and direct drums , with lightweight aluminum options available for racing applications . Companies like Sonnax have manufactured these and other internal components to be stronger and more capable , but the inherent design of the 400 transmission does leave the door open for transmission failure , some of which can be catastrophic . Sonnax ’ s new
Here you can see the original two-drum ( froward and direct ) design on the left and the new Sonnax drum module on the right . The difference in cast-iron versus aluminum construction is easily noted , and it ’ s important to consider that the heavier internal parts are now more closely located at the centerline of the transmission . This requires less power to drive the components .
Smart-Tech Turbo 400 Drum Module is capable of eliminating that situation altogether by replacing the entire OE drum system with a unique combination of lighter and stronger components .
drum combination because the mass is more centered in the rotating assembly .
“ We intended it to be a system to bring more efficiency to the transmission for class racers ,” explains Sonnax High Performance Product Line Manager Gregg Nader . “ As it developed , we realized it would have a lot of capacity , too .”
Nader notes that the Sonnax Smart-Tech Turbo 400 Drum Module is capable of supporting anything from 500-3,500 hp .
“ That ’ s amazing unto itself , and then you have the whole safety side . Things can go badly when the drums explode . Within the Turbo 400 transmission the forward drum never explodes or overspeeds because it ’ s connected to the engine . The direct drum is connected to the geartrain that can hyper overdrive direct drums . With our system , there is no separate direct drum connected to the geartrain to overspeed or explode .”
Beyond that significant change in design , the
PHOTOGRAPHS COURTESY OF SONNAX
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