About CJTunes

At CJTunes, our mission is to provide our customers with top quality, race winning performance of late model GM cars and trucks, specializing in performance tuning on all GenIII and GENIV engines, spreading from the earliest LS1 to the most modern LS3, LS7, LS9's. CJTunes stands by its guiding principle – “EVERY CAR, EVERY CUSTOMER” – ensuring that the needs of EVERY CAR AND EVERY CUSTOMER will be met.

CJTunes is owned and operated by Carl Thomas, Shop Foreman, Lead Diagnostician and owner of Lancer Service Auto Care. Carl has been actively involved in the automotive industry since he was 15 years old; at age 19, he received his ASE Master Technician Certification with an L1 Advanced Drivability Degree, making him one of the youngest ever achievers. In the 2006 Technician of the Millennium contest, Carl qualified as one of the top 5 contenders in the North Central region and top forty in North America . His runner up finish at the Semi-Final contest prevented him from going on to the finals. However, Carl anxiously awaits the next Technician of the Millennium challenge.

All vehicles are tuned using HPtuners and logged using an innovate LM-1 portable wide band, in conjunction with a rail mounted fuel pressure transducer. At CJTunes we welcome any cars with existing performance/ check engine light issues as well.

For further information or inquiries, please contact us here. We look forward to working with you!

Intro to tuning

There are two primary modes in which to run your Gen3/Gen4 engine.

1. Mass Airflow Sensor

The first is with the mass airflow sensor enabled. In this mode your mass airflow sensor reads all of the air your engine ingests and in doing so sends a signal to your engine control module (ecm). Your ecm takes this reading along with many other sensors (intake air temp, coolant temp, throttle position sensor, engine speed, etc.) and controls two primary outputs. Spark timing and fuel control/injector on time.

To put it simply, your ECM is essentially a foreman or a company CEO, it takes input, uses a decision making process and commands components to operate.

Unlike your boss, your ecm is very consistent in making decisions because it looks at a series of base, adder and multiplier tables that it cannot deviate from.

It uses the inputs makes a calculation and provides outputs to many different systems.

2. Speed Density

Speed density is identical to the MAF mode other than instead of using the MAF sensor the ECM relies on your manifold absolute pressure sensor to determine the engine load. The manifold absolute pressure sensor (MAP) is located in your intake manifold and works off of vacuum to calculate engine load. Since the MAP sensor cannot actually read the amount of air that enters the engine your ECM uses multiple inputs such as engine speed, available vacuum, intake air temperature and barometric pressure readings to make calculations. In speed density mode, your ECM references a completely different set of base, adder and multiplier tables to make output decisions. What we do is step in and make required changes to the lookup tables in order to make the ecm perform operations correctly. This means that the power we extract through tuning is due to changes that improve efficiency. Improved engine efficiency promotes better combustion and more power and better fuel economy. If you have a modified car (anything from headers all the way to a twin turbo setup), you must get your vehicle tuned, if you don't you will be losing efficiency and, in turn, power.