After reading this...I think you even more right !!
http://www.v6performance.net/forums/showthread.php?t=32515&page=1&pp=20&highlight=ground+wire
What does a ground cable kit do?
A ground cable kit is a ground… which in this case prevents spikes in electrical signals. Our cars have electrical signals that go from all of the sensors to the ECU and then from these signals the ECU sends out signals that control the engine, air fuel, … When a good ground is not provided it allows for a spike in the electrical signals that are being received and sent out by the ECU. When this happens the signal is slightly modified causing the car to not run the way the ECU intended it to.
It is like when you are trying to talk to someone on a cell phone when you are in a tunnel and the reception is bad. The signal cuts in and out and you cannot fully understand what is being said and neither can the other person. A ground cable kit will give a full and clear signal and remove most if not all of the impurities in the signals being sent and received. This will allow your car to run more efficiently which will allow for better performance.
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It is the spikes I'm feeling when keeping a certain RPM on.
How I can do my own custom ground kit ?? Where to connect in the trunk (seems to not have a good spot for it in the trunk)....