View Full Version : Relocating the battery to the trunk

08-07-2004, 02:36 PM
I was considering relocating the battery on my 04 Cobra to the RH side of the trunk. The Cobra is fairly nose heavy with a weight distribution of 57/43. The battery is located in front of the front axel which means it's cantilevers the weight off the rear end. By moving the battery behind the rear axel whould have the oppisite effect taking weight off the front end and planting over the rear wheels giving better rear wheel traction and better chassis balance. I did this on my 72 Dodge Challenger using "00" gauge wire (the guage of the wire needs to heavier due to the longer run to the starter). I have not done the math but I bet this would change the weight distribution to 56/44 or better.

Wudda ya think?


08-16-2004, 07:08 AM
I did this on my 2000 GT and now on my 2003 Cobra. I whole-heartedly recommend anyone relocate their battery; especially if they want to do any road racing and/or autocrossing.

Yes, the Mustang is a front-heavy pig. The biggest problem with the SN95 is it's weight and weight distribution.

It's not an easy job relocating. It's a purely custom job and increases with difficulty depending on how nice you want it look. The toughest part is deciding where the cables exit the car to the engine bay...unless there's a existing hole I'm not aware of.

It's not terribly cheap if you want a top-rate job either. An aluminum box and the right cables (I recommend large gauge Taylor cables) will run you 200-300 bucks. But, you have $34K car, so a few hundred is worth it I think.

Don't get fancy with connecting the cables to the starter or frame or where ever. Just bring them to the OEM battery cables and connect them there. There are a host of smaller cables coming off the OE battery cables (at the battery) that you don't want to overlook. I brought my cables to the factory points and the car starts fine.

No word on how the 18-plus feet of extra battery cable affects the alternator; we'll have to see on that one. I did upgrade the battery strenght a bit too. I went with a Optima since the OEM battery didn't fit into my battery box and I did want to risk any leaks or cracks in a wreck. By the way, the rear-right location puts the battery next to the fuel filler tube; you'll NEED a good battery box mounted very well!!!

Good luck. It is needed and it is worth it.

Let me know how it goes.

08-16-2004, 02:17 PM
Ahhh, JJRraiser, you bring my post back from the "dead" (much thanks).

Question: what are taylor cabels and what is their claim to fame? ($200-300 bucks is a lot of mullah for wire). I was thinking about using aircraft grade wire.

I don't think relocating the battery with the longer run wire will have any effect on the alternator. Just need to make sure with the long run of wire that the guage is adeguate to carry the load to the starter motor (probably "0" or "00", I need to do the calculation for a maximum 3-5% voltage drop)

Any issue with disconnecting the battery from the electrical system? With all those computors some of them might wanna reset themselves or something.

Thanks man

Russ :baby:

08-17-2004, 07:35 AM
Glad I could resurrect your thread. I'm surprised a bit more aren't into this mod. Anytime you can lower the weight and/or move toward a 50/50 balance, it's a great mod! You don't need more power when you reduce weight. Reducing weight is the ONLY mod that improves acceleration, braking, and handling all at the same time! Anyway....

Taylor cables are merely electrical wires for automotive uses. You're right, any good, large gauge cables will work. The 200-300 bucks was not only for the cables, but an aluminum battery box too. You can get a plastic one for much cheaper, but it really needs to be in a box.

As far as disconnecting the battery, I've had no problems with numerous disconnects on both my 2000 GT and my current 2003 Cobra.

Good luck.

08-19-2004, 09:52 PM
Check your local welding supply house for cable. Welding cable is ALOT cheaper that the pretty translucent Phoenix Gold, Monster Cable, etc. etc. and works just as well.

Run a 1/0 and you should be fine. The battery is used for cranking only. Once the car is running, it then runs off the alternator. Plus if you run 1/0 and add a big stereo later, you won't have to worry about voltage drop. :thumbsup:

08-27-2004, 08:07 PM
what about track use? dont u need a cutoff switch?

08-28-2004, 08:05 AM
what about track use? dont u need a cutoff switch?
I thinkk that applies to race events and not HPDE/ Driving schools.:)