http://www.350z-tech.com/zwiki/Tutorial ... stallation
Automotive electrical and computer systems are designed to tolerate up to 100% noise on their input lines. Meaning, if the ECU is expecting a 12-volt input signal, the signal may vary in the range of 0 to 12 volts.
Fluctuations in signal are due to noise and resistance in the system. Noise is generated by spark plugs firing, discharges through the tires to the road, alternator turning on/off, etc. Resistance is the inability of the system to conduct electricity properly.
One of the best-proven ways to compensate for noise and resistance is with proper grounding. Engine grounding has been used in the racing industry for years. The benefits have been proven and documented.
The Custom Engine Grounding Kit allows for cleaner data transfer to the ECU. The result is more accurate measurements by the ECU and therefore more accurate performance, smoother idle and better acceleration.