running a ground wire.

hi, i got a question about running negitiave ground wire from the battery.

ok someone on another forum says that because our cars have an aluminion(sp) unibody that running and grounding wire from the battery is better then just connecting it a peaice of bare mental for voltage drop reasons. and he thinks that because some guy from batcap told him to and also talked him into buying like 7 batcaps for roughly about the same rms that my system is going to be ( roughly around 2700 to 3300 rms)

He was lied to. The car is not entirely aluminum or palstic for that matter. There is still steel in the car. Even if it was entirely aluminum, its still metal and its conductivity should be close to steel. Most houses use aluminum grounding posts/wire anyways so its not a problem. If this was the case then cars like the corvette and NSX would not be able to have their batterys grounded to the chassis due to the fact that they are aluminum. On all cars the engine, battery, alternator, and all other grounds are connected to the chassis at some point.

He was lied to. The car is not entirely aluminum or palstic for that matter. There is still steel in the car. Even if it was entirely aluminum, its still metal and its conductivity should be close to steel. Most houses use aluminum grounding posts/wire anyways so its not a problem. If this was the case then cars like the corvette and NSX would not be able to have their batterys grounded to the chassis due to the fact that they are aluminum. On all cars the engine, battery, alternator, and all other grounds are connected to the chassis at some point.

thats what i was trying to tell him, even better argument is that alot of compnays like knukonceptz are mixing aluminon and copper for there power wire. and to make it even wrose for him is that when i take a dmm to my amps i get a higher voltage then what my battery has ( both when the car is off)

running a ground wire from the battery up front to the amps in back will just increase the odds of having engine noise. Sounds like batcap salesman must have stock in the cable industry.