Getting my first real-time, EFI Dyno tune today for $500

On a slightly related note, I just got back from Sacramento where I had my 2008 GMC 2500HD 6.0/6-speed auto dyno tuned. I added a cold air intake and a Corsa catback exhaust to the 74k mile truck.

The baseline run showed 273hp at the rear wheels. The motor was only burning at 14.5 to 1 AFR. After some tuning, the motor spun out 310hp. A nice gain on California pump REGULAR.

The biggest improvement was in how the guy tuned the computer controlled transmission. He set it up like they are in the ZL1 cars. The truck has been transformed into a completely different animal now. It's like night and day in how the truck daily drives and runs at full throttle. I highly recommend this upgrade if you have a newer vehicle.