E30 Battery to Boot installation - help appreciated

[RipJaws 3]

Hi all,

I was considering swapping my battery to the boot for 1. my fastening brackets for the battery were all but gone when I got the car and 2. it more evenly distributes the weight of the car (but woop dee doo, I'm not racing the thing) 3. the tray where it is currently sitting in the engine bay looks as though to be a nice place for my alarm siren to sit.

I have done a little research on this whole business of relocating the power unit and noticed that some BMW E30's came standard with the battery in the boot. There seems to be a perfect little spot just behind the drivers side wheel arch in the boot.

Anyway my question is: How many cables will I need? As I am worried if I don't route every cable going to my positive battery terminal I might heat something up and destroy it. Today i bought 4 metres of 8 gauge twin power cable.

http://postimg.org/image/861trmltn/

The guy at JayCar said I should be fine with that, just route positive to positive and use the length to keep it simple and go from the negative along to the front of the car and connect it where the current negative is sitting.

http://postimg.org/image/rbg73g641/

Then I bought a high amp wire connecter hub so I can grab the current array of wires from where my positive terminal sits and tidily route them into it and then have my cables from the boot meeting up with them there. I have around 3 cables going into the positive terminal at the moment and there is where I am unsure. How can I just use 1 cable from the boot to meet up with 3 cables from the engine bay?

http://postimg.org/image/7mowuxzm1/

I have a spare cable that goes to an amp I could use as well. Anyway, any insight on this would be great. Thanks guys.

[RipJaws 3]

I know the terminals are terrible! I have got some new ones and I will be sorting that when the battery goes into the boot.

[_ethrty-Andy_ 2132]

all 325i coupes and sedans have them in the boot, so you can find retrofit kits easy enough, any wrecker should have it.

But is it worth it?? having done it before, its a pain in the ass, most of the interior has to come out etc, and for what. its only 20kg or so, and you are probably adding about half that again in cables anyways.

[1rotty 40]

I have a retro fit here if you're interested

[RipJaws 3]

I have a retro fit here if you're interested

Okay that seems interesting, I will give you a text Mark. I was supposed to the other day when I was looking for a bleeder screw and that caliper spring. I got caught up so I'll contact you in the next day or so. Cheers.

And yeah I agree Andy it does seem a little pointless but I kept that in mind. Its annoying knowing my battery is sliding around on every corner lol.

I have all these expensive cables! agh what a waste

[_ethrty-Andy_ 2132]

Okay that seems interesting, I will give you a text Mark. I was supposed to the other day when I was looking for a bleeder screw and that caliper spring. I got caught up so I'll contact you in the next day or so. Cheers.

And yeah I agree Andy it does seem a little pointless but I kept that in mind. Its annoying knowing my battery is sliding around on every corner lol.

I have all these expensive cables! agh what a waste

Cool! let me know if you need any pointers! pretty easy to d just time consuming. Toughest part is poking it through from firewall, especially if dash is in place.

[yng_750 247]

Best net it retrofit kit as that will fit perfectly. 8guage is just not big enough for starting draw. and the negative can be grounded to the chassis at the back so no need to run two cabled. Just give very good connections to ground

[e30ftw 410]

It's real easy if you have all the bits. All the holes are there for mounting the positive terminal cradle and the hole into the firewall. But as Andy said it's an absolute nightmare trying to get the cable through, I suggest feeding it INTO the car through the hole in firewall, as the rubber grommet on the cable where it pops in through firewall is impossible to sit right from the inside.

Other than that easy as to tuck under the carpet along the side and feed into the boot. You can use the rear bumper bolt as the earth terminal so you need only a short eart even the same as you have in the engine bay, works fine done it twice. Even managed the swap on my touring quite straight forward.

[RipJaws 3]

Cool! let me know if you need any pointers! pretty easy to d just time consuming. Toughest part is poking it through from firewall, especially if dash is in place.

Cheers mate I might come back when I have the right stuff for it if I get hung up on routing all the bits.

Wow, okay thank you so much guys. The main thing I was worried about was getting enough power and the right type of cable down the length of the car.... So even though the negative screws into the driver side strut and grounds with some other cables that come from inside the cabin through the fire wall I can still just have a short earth at the boot?? What happens to those other cables screwed into the strut tower?

I don't know a lot about cable gauges or anything so I was trusting the guy at Jay Car to see me right. Hopefully I can get a refund for the cable I bought. I'm going to get the retro fit kit off Mark I think.

Cheers all

[aja540i 1906]

Cheers mate I might come back when I have the right stuff for it if I get hung up on routing all the bits.

Wow, okay thank you so much guys. The main thing I was worried about was getting enough power and the right type of cable down the length of the car.... So even though the negative screws into the driver side strut and grounds with some other cables that come from inside the cabin through the fire wall I can still just have a short earth at the boot?? What happens to those other cables screwed into the strut tower?

I don't know a lot about cable gauges or anything so I was trusting the guy at Jay Car to see me right. Hopefully I can get a refund for the cable I bought. I'm going to get the retro fit kit off Mark I think.

Cheers all

Just leave all the other earth cables bolted to the strut tower and put a good earth in the boot to the battery, the chassis does the rest! Good luck.

[RipJaws 3]

So I can be completely certain that 8 gauge cable won't carry all the current I need? I need to be sure because I rang JayCar about taking the stuff back I bought and they don't seem to good about me returning cable off the reels. He was confident I would be right with the stuff he recommended so if they have a problem with that I will just make that clear I guess.