Matt Cramer is an engineer with DIYAutoTune.com, an aftermarket engine electronics firm. He is the coauthor with Jerry Hoffmann of Performance Fuel Injection Systems HP1557.

Jerry Hoffmann is the founder/CEO of DIYAutoTune.com. With an IT background and being a lifetime car-guy hobbyist, he found a need for affordable engine management and education during one of his own projects when turbocharging a personal car and melded his computer career with his love for cars. His company specializes in equipping do-it-yourselfers to actually hand-build and implement electronic fuel injection systems in their own garage. And as such Hoffmann has installed and tuned EFI systems on numerous vehicles, street-driven classics, road-course- club racers, drag racers, and land-speed cars out at the Bonneville Salt Flats. His aim is to help others understand EFI in a practical hands-on manner, with less interest on the engineering ease and more focus on the practical need-to-know-how, and to empower people to affordably and knowledgeably build and implement their own EFI systems on their favorite automotive monstrosities.