By JET Performance

The CTS-V is a member of Cadillac’s V-series of cars, which means it has a whole bunch of high performance under the techno-styled exterior.
The CTS-V is powered by a Gen III V8, an LS6 up to 2005, and now the LS2 for 2006. The LS6 version cranked out over 320 horsepower to the rear wheels on the DynoJET chassis dyno at Finish Line Performance. That’s more power than most Corvettes ever made until the past couple years. On the track, the CTS-V runs low 13-second quarters all day long.
But that doesn’t mean it can’t be improved upon. We grabbed a 2005 CTS-V and a new JET Performance Products Programmer and headed out the Finish Line Performance to see if we could squeeze out more juice from this sled.
Our baseline runs netted us 328 HP and 315ft. lbs of torque. The JET Performance Products Programmer comes with 3 levels of tune built-in, with the ability to make various other modifications to the vehicle as you see fit. For example, you can disable the CAGS – the Computer Assisted Gear Selection, or “Skip Shift� which forces your hand from 1st gear to 4th under light acceleration for emissions reasons. We hate it, so we were glad you can turn it off with the JET box.
Other mods you can make include correcting the speedometer for modified tire sizes, disabling the top speed limited, and changing the rev limiter value. You can also use the JET Performance Programmer as a scan tool to check and clear OBDII diagnostic codes.

The first step is to remove the OnStar satellite navigation / vehicluar monitoring system fuse from the fuse panel located under the rear seat. You have to pull this fuse during programming so the car doesn't tell OnStar that there's a big problem. When finished, you can reconnect the fuse and everything should be fine.

We connected the Programmer to the car to upload the first tune, but we were greeted with a “NOT FOR THIS VEHICLE� message. We checked to see we had the right part number, but it turned out that some of the CTS-V’s came out of the factory without their VIN properly flashed into the computer, so the programmer couldn’t lock onto the car’s VIN. These programmers are set up so that they only work with one vehicle so that you can’t open up a tuning shop using one programmer; you have to buy one for each vehicle. We had the VIN hiccup fixed at the dealer… it turns out that there was a Technical Service Bulletin issued by GM that fixed it for free.
Now we could start our tune session. The Programmer asks you simple yes/no questions about the car and the level of tune-up you want to add, and you just hit the appropriate key to answer. It’s simple. After a couple minutes, your stock tune has been removed from the car and saved to the Programmer, and the new tune is installed in the car.
Our first run on level 1 didn’t really show much improvement, so we moved up to level 2. We experienced a mild 2 horsepower gain, with a slight increase in torque. The air/fuel ratio seemed to be cleaning up, so we decided to try the third tune stage.
The instructions warn that you should only run the stage three tuning if your car has a performance intake and exhaust system, which tells us the programmer modifies the values for the mass air meter in stage three. Our test car was totally stock, but we ran it anyway. The results? An increase of 12hp and 13 ft.lbs. of torque, along with a cleaner air/fuel ratio curve.
The JET Performance Programmer really helped find more power. In all honesty, we were pretty convinced that the GM engineers had the max tune in place from the factory, but the JET box showed us they left a little something on the table.
Check the JET Performance Products website for other applications.