I'm planning a build and i'm thinking about amp placement. I know that amps should be grounded around 18" or less but i've seen builds where the grounds are four plus feet, anyone care to shed light on this, is it ok if excellent wire is used?

BTW the build was from a person whos name that can't be mentioned.

Everybody chooses or cites arbitrary lengths of wire for grounds. None of them mean anything in reality. The increase in resistance from 4' of wire isn't going to be enough to matter in daily systems. It's more important that the wire is terminated to a good location in the vehicle than keeping the wire some arbitrary length.

the reason for the short runs is so that there is less resistance. the longer piece u have the more resistance that can come about. i have 3 grounds, i have front to rear and one on each side of the truck off my batts 52" apart

Ideally you want them short to prevent ground loops and the fact that the entire chassis of the vehicle is a ground pretty much facilitates no need for a long run of cable. All vehicles are different though and the path of least resistance may even be a direct cable back to the battery. It's pretty much just personal preference.

Best to keep the run as close to the amp as possible, but It does not seem to bother his set up tho, so go figure.

I have mine grounded to the batteries in back that are about a foot/foot-1/2 away from the amps and the rear batteries are grounded to the frame below. The frame is probably another foot foot-1/2 to the amp.

I have a Powermaster for the trunk. just double-checkin on that. The grounds from the amp to the battery are gonna be roughly 2-3 feet apart.