grounding kit, big 3, etc.

Hello, Im from Brazil, i have read some topics, and i have questions:

Recently, more attention has been paid to the benefit of providing multiple ground points to an engine.  There have been plenty of articles in enthusiasts' magazines that show small but significant increases in horsepower by simply adding additional ground or "earthing" wires.  Here in the United States, "grounding" is the term used.  Practically every other English speaking country in the world calls it "earthing."

Conventional thinking used to be that grounding was an "all or nothing" phenomenon.  Either your car battery was grounded, or it wasn't.  The amount of electrical current running through the negative battery terminal is equal to that running through the positive end.  The battery represents part of a giant, complete circuit for everything electrical in the car, no matter how far away that component is from the battery, or more precisely, the battery ground.  

Doesn't grounding to two spots on the body and or motor cause potential ground loops? I thought you were only supposed to ground to one location (one spot on the body and one spot on the motor)... so wouldn't replacing the factory 8 guage ground wires with 4 guage be a better solution?

thank you for reply my friend;

but, if one wire or ground point have a lower resistence than other, this doesn't sufficient to cause a ground loop?

i have read this on http://www.k0bg.com/loops.html

"The term Ground Loop in itself isn't very descriptive, but here's a stab at it with credit going to Mr. Webster: An unwanted electric current path in a circuit resulting in stray signals or interference, occurring, e.g., when two earthed points in the same circuit have different potentials. Please pay particular attention the last few words: ...when two earthed points in the same circuit have different potentials. Another way to look at this is, one is a better ground than the other. Or, one has a lower resistance path back to the power source; the battery in this case."

i worried about the two or more ground points in the negative of battery to the chassis, can cause ground loop;  it do the big 3 and maintain the original wires

i have adding one more wire to the negative battery terminal at another point in the chassis

I could be wrong on this but I though that a ground loop was when the ground signal could travel across two paths back to the battery with varying resistance (I'm certainly no expert on this and this could be totally wrong, I just though this was the theory.)