Cars use a DC power system consisting of 12~ volts positive power and negative/ground. All devices have power wires going to them (after running through a fuse) and return wires that eventually get back to the negative battery terminal. The issue is that most of the devices in your car use small wires (not just gauge but small in physical length) to go from the device and then terminate at the chassis nearby. Then your power flows around your car chassis until it eventually gets to the battery. This is a very high resistance path to ground, not optimal at all for signal quality. Ground paths should always be less than a couple ohms, and in cars it is not when it has to flow through the chassis to get back. The reason this method is done is because it saves not only a couple hundred $$ per car to build (in actual copper wire costs for all the devices in the car) but also saves a lot of space not needed for basically doubling the wires in the car. Does it work? Sure. Is it good? Nope.Larz wrote: ↑Sat Nov 17, 2018 7:45 pmI have been researching grounding kits for over a year now. I can find NO actual data that supports using one in standard passenger cars. I HAVE seen documentation of 4-5 BHP gains, and slight improvement in performance of poorly installed aftermarket sound systems, etc. A gain of 4-5 BHP is like the difference between a 15w and 20w bulb - yes it's more, but hardly worth mentioning. Other than that, I can find nothing to support installing a grounding kit. There are no reports of widespread electrical failures on cars without grounding kits. No reports of safety issues, etc.
What am I missing here?
By adding real ground wires you are lowering the circuit resistance of various devices by a couple dozen ohms as well as providing a cleaner signal path and a faster signal path. [tangent]The faster signal path shouldnt matter much since electrical waves travel extremely fast. I have no way of doing the calculation for the car and it would really depend on how long the signal path is going through chassis, but providing a real path to ground from these wires would probably increase the speed somewhere between 1-2 million miles per hour over the current speed. Sounds funny, but considering Id estimate the speed of the current system to most likely be between 604-617 million miles per hour, increasing by 1-2 million mph isnt that much. [/tangent] So the main thing you are providing if not a "faster" signal path in pure speed is a cleaner signal path. By reducing the resistance of the ground side of the circuit by such a large amount you are letting the power flow more easily which produces less wasted energy, meaning less needs to be taken from the cars electrical system, but also lets the devices operate better. This cleaner power for instance can result in better audio volume, or slightly brighter headlights, cleaner sounding audio, less light dimming in aftermarket audio systems when the bass hits really hard and draws a bunch of current. For me it also resulted in slightly faster shift times in manual shift mode on the car when driving very aggressive.