Transmission shops that participate in automatic performance work find that most of the work is either street rods or pickup trucks, particularly diesel pickups. In February 2021, TD published a detailed article focused on diesel truck transmissions and converters with Blake Carter of Suncoast.
The first question that comes to mind are what effects the pandemic has had on performance work. Ken Kelly, president of Transmission Specialties, says business is good. Kelly’s company concentrates on units and components for street rod and drag racing applications and, most recently, diesel application converters.

“We kept busier than we’ve ever been, but during COVID they shut down a lot of racetracks, due to local laws. NHRA canceled national events as well. So COVID definitely affected the racing industry but from a business standpoint, guys, whether they were home or whatever, continued working on those cars and buying parts.
“The Powerglide and the Turbo 400 are the prominent drag racing transmissions to this day and they’re bigger and better than ever. As the vehicle power levels increase, people are moving to oversize in those units. You can put in big input shafts now, inch and a quarter input shafts in a Powerglide that normally had a three-quarter inch one. So, you can oversize that unit all the way out to the output shaft. The same is true with the Turbo 400. They’re oversizing all those shafts in those transmissions to handle even more power. That’s the new craze.”
A valuable profit opportunity comes in the form of upgrading flex plates. “If you’re going to be upgrading,” says J.C. Beattie, Jr., CEO of ATI Performance, “you’ve got your cooler pressure pushing and pulling on the converter. As you have more performance and need more line pressure, your pressure goes up, you get a stall converter. Maybe the Stater cap doesn’t have any big holes in it and your cooler pressure goes up. So, your flex plate needs to be able to handle the flex forward and back. At the end of the day, the flex plate is there to take up some of the tolerances that are stacked up from your crank to your bearing clearance, to the converter pad to the pump, to the transmission alignment. So, there’s going to be some tolerance that stacks up and needs to be accounted for. And the flex plate also sucks up some of that. It’s a pretty important consideration, even on a mild car.”

Beattie observes that the most demanding applications, those with very high horsepower, will call for a billet flex plate, a specialty in and of itself.
From a 30,000-foot view, there are profit opportunities for the shop that can acquire and install performance upgrades for its customers. And that business, addressing the hobby interests of drivers, remains less price sensitive than stock replacements.