Mark and Gina Chapple, owners of TST Products, Inc. in Columbus, IN. promise "more power in about an hour" for several makes of diesel engines.

TST designs, manufactures, tests, and markets power upgrades for turbo diesel engines used in many Dodge, Ford, and GM pickup trucks, motorhomes and medium trucks, plus heavy trucks with Caterpillar and Cummins electronic diesels. Products offered includes: gauges, filters, exhaust brakes, transmission parts, and clutches for the diesel pickups. Brand names offered include TST, Bosch, Cummins, Pacbrake, Fleetguard, Holset, ATS, Autometer, South Bend, Smarty and many others.

"We extensively test all products before adding them to our product line, we do not want to sell anything that does not perform well for our customers."

The business was founded in 1995 by Mark Chapple, a former Cummins engineer with 33 years of service. Mark and Gina sold their first parts at a diesel rally in July 1996.

TST markets mainly by mail order and internet, but has about 500 dealers worldwide.

Gina Chapple worked part time until April 1997 when she became fulltime. Others joining the company since then include Natalie, Annette, and Sara.

Business hours are 8 am to 5 pm Monday though Friday.