AW11 MR2 Battery Relocation
  - Battery Relocation: Moving the battery to the front of an MR2

The MR2 is unique in that it is a mid-engined car.
Nothing unique, however, is the placement of the battery.
This hunk of weight sits in the engine compartment, in the rear of the car. Ideally, we should move it to the front to help the weight distribution, and clean up the engine bay a bit.
Similarly, with front engined cars, we will want to move the battery out of the front, to the rear of the car.
There are multiple ways to accomplish the Battery Relocation mod. This is just one of many.
We highly recommend picking up a Dry Cell Battery (Optima Brand, for example, as seen in this article), as lead-acid batteries are quite heavy, along with a few more notable issues.

Let's give it a go.

Alan

DANGER

Any information presented or implied is for entertainment purposes only. A car and related parts can be very dangerous to work around. Please exercise extreme caution when performing any kind of repair or modification. Neither I or any affiliated parties can be held responsible for any problems or accidents which may occur.

Battery Wiring Schematic
You will need the following:
  Battery (Dry Cell Recommended)
  4AWG Wire (25Ft.)
  Battery Box
  150A ANL Fuses + Inline Fuse Holder
  Electircal Tape
  Wire Connectors
  Distribution Blocks (2+)
  Assorted Tools		 This is a crude schematic of how the Relocated Battery will be wired.
Note the addition of multiple grounds over the stock design.

Begin by removing the Negative Lead, followed by the positive.
Do not let them come into contact with each other or with metal.		 Remove the Battery and set it aside. Notice the distance between the disconnected terminals here.

Determine where and how you will position the battery to calculate the required lengths of wire. Side view

Begin wiring the positive lead (4AWG wire) from the front of the car. There is a passthrough located under the fuse block. Once you have passed a decent length through, go to the passenger side of the cabin and locate the wire.

A very tight fit. Pull the wire through, and route it to the driver's side of the cabin, and behind the driver's seat.
Pull the interior liner back to expose a passthrough which leads to the engine compartment. Thread the wire through this opening, then locate the exit in the engine compartment and pull the wire through.

Remove the original bettery terminal from the positive lead. Strip the insulation to expose the ends of the wires.

We will use this distribution block to attach the new lead to the old positive lead. Wrap the connection with an excessive amount of electrical tape to prevent exposed contact surfaces (exposed contacts can lead to shorts and possibly fire when they come into contact with the ground).

Return to the Front where the battery is located and get ready to install the Fuse Holder.
Photo: Fuse holder and fuses		 Attach one end of the fuse holder to the wire that leads to the engine compartment. Attach the other end of the fuse holder to a short lenghth of wire.
Proceed to attach the old (+) battery terminal connector to this wire.

This is how it should look like (You may wrap the lead with electrical tape to color code it like we have). Locate a suitable ground point on the chassis, and attach the (-) ground lead to it. Proceed to attach the (+) positive lead to the battery, followed by the (-) ground lead. This ordering is extremely important; never attach the ground first. Secure the battery And proceed to attempt to start the car.

After you have confirmed that the car will start without problems, shut off the car, go back and remove the negative terminal. Since we have all of this wire available, we will ground multiple components in the engine compartment, as seen in the photo. Locate and re-ground stock grounds; create new grounds. You can do as many as you wish.

Like the grounding we have just completed in the engine compartment, we will now do to the front.
(*Ignore the lack of the battery box, we are testing an alternative mounting method here.)

Attach a distribution block to the ground terminal, and proceed to run multiple leads to any number of chassis ground points in the area.
Once satisfied, reattach the Ground lead/connector to the battery, and fire it up.

Hopefully you will notice a difference in handling after completing this modification. If not, you have at least created nice grounds and have cleaned up the engine compartment.

Comments from Satoshi: After completing this mod, refer back to the schematic at the top of this page. If it confused you earlier, you will be surprised to find that it is now quite easy to understand. Enjoy your Battery Relocation Mod!