grounding wire

i've been told that particular cars can increase their performance by simply changing/adding a grounding wire to their battery. i know some civics are said to gain 1-2 horse by something this simple. anyone know if that's the case with a cavalier? any one possible get it dyno'ed or notice a difference?

Heh...What a crock. These guys are making a killing selling RG-58U CB coaxial cable as ground wires...You put any serious current thru that wire and it'll act more like a light bulb with no glass than a ground wire.

Good idea-wrong method.
That wire doesn't much have the current carrying capability for an automotive application.
Good, low impedance grounds make for true, accurate, noise-free sensor data communication with the ECM.
Trouble is, because your alternator produces an AC voltage (granted-it's chopped and polarized to a DC voltage at the rectifier/regulator)-very little is done to filter the AC harmonic frequencies produced by the AC part of the alternator. (A side effect of producing AC current is that the alternator acts like a radio transmitter).
Trouble with ROUND wires is that they tend to resonate at certain frequencies and multiples of the true frequencies. (Hence the alternator noise ya just can't get rid of no matter what kinda filtering crap ya hang offa yer wiring...)
Best ever grounding material to use is the flat, braided ground straps, like the ones that connect your engine block to the body/frame. The bigger/wider-the better!
Don't have any? Get some and add them on anyways!
No such thing as too good a ground connection.
The bigger the ground wire-the better the response from the circuits using them.
You don't ADD performance, but rather you make the whole system realize it's FULL potential by over-grounding.
Plus-the flat wire configuration tends NOT to be susceptible to the frequency harmonics problem you'd get if ya were using round wires.
Flat wires don't resonate so easily. (That's why they make good radio antennas out of ROUND steel stock-your antenna coax that goes to your radio is ROUND. It's meant to carry a radio frequency, unmodified to your radio.
Flat braided wires are used for ground straps because they're only meant to carry DC voltage and current-not RF noise.