Alright,
I am moving my battery to the trunk while I still can. I am planning on going SR-20 in the future or even KA-T (either way, I have to move the battery) I also have a Yellow Top Optima.

Currently I am working on putting in a fiberglass Kenwood system in my car, so, I NEED to move the battery before I start doing that, so i know its location with the rest of the work.

I understand how to run the positive to the back with a connector and all

I have 3 questions:

I have a 180SX and I need to ground the negative side of the battery. Where is the BEST place to ground the battery in the trunk?

I am also going to have to ground the amps for the sound system, should I ground the amps to the same place as the battery or what?

Also, is there some sort of grounding box I can install in the trunk if I can just ground it all to the same place?

 

there should be bolt holes somewhere in ur trunk. all i did was took a sander and sanded the paint off to expose the bare metal. and took a threaded bolt and nut and bolted the strap to the body. if u want u can use the part where the spare tire was bolted down to. a ground is a ground

???? Do u have a box for the battery u will need one if u are going to the track and stuff.

and u have a real 180sx or coverted 180sx?

 

ANYWHERE!!!!
Ground it anywhere that its actually the car. Don't ground it to a shock or somethign :P . If you really want a good ground go as follows:
choose a confortable place, since you'll have to acces it when you put the amp and stuff.
Grind a litle metal with a dremel or a sand paper
drill a whole about 1/4 of an inch
buy stainles steel bolts, 2 washers and a nut
put them trough the hole and screw them in, with the negative cable in between them. Screw tight as hell
paint over with rustoleum paint, make sure its really clean before you paint.

Or you can use a bolt from the seatbelts area.

I have a 93 240 and I used the bolt that holds the cover for the fuel pump. I recognize using the closest bolt to a fuel pump for a 500W system is not smart, I shall reconfigure soon.

There are these hook up joints they sell, if you have many litle amps, you can use a huge wire, then screw it in one end and on the other side has many holes where you put the small wires and they are held in by a screw from the top of the wire. they look very profesional, you might want to put it where's is visible since they look hot too. you can use them fro the positive or negative cables, don't matter. now one thing, do your math. Remember to add a thicker bable everytime you join two into one ( like the hook up place) and put fuses in the line. One last thing, don't forget to ground the front negative of the batery, or make sure that its really correctly. Good luck

 

mine is just on the floor... grind off the paint so it touches metal and put it anywhere.

 

Drill into the chassis, use a large bolt, and if you can try to ground all of your aftermarket audio stuff to the same point to eliminate any ground loops and possible speaker hum.

 

Keep your Fiberglass install clean by getting an Oddysey Battery and leaving it under the Hood. It's small enough for Intercooler Pipes to not have clearence issues. Closer to ECU the better.

 

The vacinity of battery placement has no type of influence on the ECU. I have no clue as to where you got that idea from.

If the install and wiring are done correct, you will actually be improving conditions by removing worn and corroded terminals and replacing with new ones, using high conductive copper wiring, improving overall weight distribution throughout by moving the weight of the battery to the rear, opening up room in the engine bay, ect...

He has a yellow top Optima battery, which isn't cheap and does more than enough to supply power to the car and his sound system. I highly doubt he wants to replace it.

Just move the Optima to the back. Use a marine battery box that you can pick up at Autozone for about $15. Pick up some 4 gauge copper wire (power), about 15 feet of red and 3 or 4 feet of black (ground). Go to Car Toys or somewhere of the sort and pick up a distribution block, 60amp fuse and fuse holder, and that's about all you need.

Here are a few pics of my relocation that I did in my CRX:







You can see that I used the chassis for the ground, as a few people have recommended here. Also, the distribution block is pictured by the intake in the last pic. You'd be suprised how the handling characteristics change by moving the battery to the back. My terminals and stock electrical connections were really worn and/or corroded on my CRX. After replacing everything, I noticed brighter lights, easier starts, and a better sounding system. I'd recommend doing the relocation.

 

Well than let me give you a clue where I got that Idea from. Put a Multi-meter on Ecu, and MAF and test Voltage and Ohms before and after moving Battery to the back and you will see that the Ecu sees less Voltage, and the added length of cable puts more Resistance on the Charging System, I don't care what gauge wire is being used. The Alternator in the 240 cycles on and off its not charging the car 100% of the time it's actually less than 50%. So if you car is Fuel Injected and youre running accessories and what not Your Ecu, Charging, and Starting system is seeing less voltage and more resistance. Some might think the difference is Negligible but when trying to squeeze every bit of Power and having a system at the same time I just thought I'd give BarnDog another option. BarnDog said he was doing a Fiberglass install in the trunk. I've been there before and the time and effort saved not incorporating it it the rear could make up for the cost of a smaller Battery. And I'm Sure that Handling is tops on his list when he's putting a System in his ride. Plus anyone would see in Improvement in Light Brightness, etc.. with basic Charging system Maintence even in a 4 foot long CRX.

 

To retain maximum voltage over longer DC power cable you just need to use thicker cable (resistance is higher so you need to increase current capacity). There is a formulae - have a look at this page
http://www.epanorama.net/documents/w...esistance.html

 

I got a little off topic but you guys are right but there are advantages and disadvantages just wanted main man to know.