PDA

View Full Version : Battery to the boot questions.



1hotvr4
26-06-2008, 05:18 AM
I finally decided to keep my beloved VR4 since i wanted to own 1 for a very long time. Up is the first thing i want to do is to relocate the battery to the boot and have the following questions.

1. When relocating the battery to the boot, can an audio cable be used and i mean the thick one that u buy when connecting the amplifyer to the battery that comes with a fuse.

2. As for a negative wire, does it need to be run from the engine bay because originally it is connected to the gearbox via the bolt, or can i just bolt it to the body of the car in the boot?

bradc
26-06-2008, 06:19 AM
Mine is grounded to the boot and nothing else, but the engine has extra grounds running to the chassis.

You need very thick cable rated at 120a, I think 0awg and 2awg are the best options.

bradc
26-06-2008, 06:25 AM
don't forget a fuse as well in the boot!

1hotvr4
26-06-2008, 06:28 AM
so ill be looking for a thick cable, and what about the fuse?? what i need it for as i dont recall the original positive wire having 1. So U reckon i can just have a negative terminal connected to the body in the back??

bradc
26-06-2008, 06:43 AM
in case the wire rubs on a part of the body and shorts everything out, then catches on fire

1hotvr4
26-06-2008, 06:58 AM
And i assume we dont want that to happend lol.

Eurospec
26-06-2008, 09:10 AM
I would use 1ga, or 0 ga for the posative wire with a big fuse in the boot.

Earth the negative to a good structural point in the boot. On my own car i also ran some 4ga to the front earthing points for the negative.

Cheers,

Ben.

Subaru ETA
26-06-2008, 10:35 AM
the origanal positive is fused. its in the fuse box! its the main fuse.

but as brad says, you will need a fuse in the boot too incase it rubs

1hotvr4
26-06-2008, 05:52 PM
ok thanx guys

Gly
26-06-2008, 08:28 PM
use welding cable, 50mm^2 will do the job nicely,
get it from BOC ,

5m is needed and will be around 80-90$

1hotvr4
27-06-2008, 07:01 AM
so far the thickest i have found is 25mm2 but will keep on looking

Gly
27-06-2008, 07:53 AM
http://yellow.co.nz/search/auckland/BOC-1.html

call one,

1hotvr4
27-06-2008, 05:20 PM
my brain just doesnt function properly does it?? /pan

Munta
27-06-2008, 10:43 PM
ive also been wanting to do this - will not 2x 4ga cables be enough to run thru to the front? ive been looking for a way around getting thicker as 4ga is the thickest we sell at my work so i get a good discount

after a quick search on google found this..

As for how much current a size cable can carry:
14ga = 15A
12ga = 20A
10ga = 30A
8ga = 80A
6ga = 105A
4ga = 140A
2ga = 190A
1ga = 220A
1/0 = 260A
2/0 = 300A
These wire ampacities are according to the NEC (National Electrical Code) and are set for wire to be used in any structure. The wire can actually carry more current than what I have listed, taking consideration that the wire is in an environment that it can be cooled or is in an open-air environment.

found @ http://answers.yahoo.com/question/index?qid=20080601053957AAmdYoy

bradc
28-06-2008, 12:18 AM
The car will draw around 100A when starting up, maybe even a bit more. I think that 2x 4ga cables would be more than capable, they'd handle 280A which is very high!

Gly
28-06-2008, 03:49 AM
it actually draws closer to 200amps at crank,
but it does it so fast and for such a short time the fuse does not pop.

the 50mm^2 welding cable is equivilant to 1/0 = 260A,
but its rated much higher than this... at least 2x more current carrying abillity.
and its double insulated.

i wouldnt use anything else than welding cable, its fairly cheap.
i wouldnt cut corners on something that carriers power down the length of you car

Munta
28-06-2008, 04:51 AM
how big fuse/ circuit breaker would be needed? i have found a 100amp one on TM at the mo

Gly
28-06-2008, 05:46 AM
120-150amp

miikka
28-06-2008, 08:35 AM
I used 2x 25mm^2 cable, it's easier to bend and protect :)

Fully
28-06-2008, 02:28 PM
I welded a M8 bolt into my boot, for a very good negative point.
Used to also ground my amps.
Then used 2 * 4g high currant cables, 1 connected to the alternator.
The other connected to the fuse box at the 100amp fuse.

CANDEE
29-06-2008, 11:45 PM
The reason for using the bigger cable is that it is less likely to heat up and therefore catch on fire. :)

Kenneth
30-06-2008, 12:08 AM
It all depends on your continuous current requirements.

Cranking is only for a short period of time and you don't need to have cable rated at the current required for cranking.

I used 25mm2 cable for the battery relocation in the Galant. I don't have a big ICE install that requires much current though, so the continuous current draw is only what is required to keep the car operating, which you don't need a battery for anyway. (car will run fine once started without a battery connected)

chris vr4
30-06-2008, 12:38 AM
i have just got my legnum and i am not clued up at all yet.
can sum1 tell me the advantages of doing this???

d i c k i e s
30-06-2008, 01:14 AM
only if your looking at doing sum big peformance upgrades in the engine bay, removing the battery to the boot will allow you to do so. where the battery is located allows you to install/make custom cold air box.

Do a search for it (cold air box) on this forum, not google.. hehehe.

CANDEE
30-06-2008, 01:44 AM
It also can be done to better your weight distribution. Expec when you have a 20kg battery.... /pan

Nicky123
01-07-2008, 11:58 PM
N-Spec Motorsport in Manukau quoted NZD$200 to move batery to boot.
I thought this was reasonable, anyone else?
I have a HUGE air intake that has a POD filter in front of passenger side wheel well. Looks cool, but mechanic reckons the pipe gets too hot to touch so negates any benefits of the cold air intake, so he suggest a cold air box and panel filter.

Goku
02-07-2008, 12:08 AM
He's basically saying put the old one back in and use a high performance panel filter lol

As for earthing on the boot install, I just drilled a hole in the boot and ran the welding wire through and mounted it to the chassis rail. There is a threaded 10mm hole on the chassis rail you can mount straight into :D.

And yes, I have used a grommet to stop any rubbing.

Kenneth
02-07-2008, 12:30 AM
$200 isn't bad at all if it includes all the hardware. Harware retails for over $100 usually just for the cable.

and you get piece of mind that someone who knows what they are doing (hopefully) is doing the job.

Advice about the intake is good, we have found standard airbox with panel filter tend to work better.

Grizzly
03-07-2008, 04:58 PM
Good thread, guys! Right in time for me :)

Any suggestions on how to route cable from trunk to engine bay? What way YOU did it?

Kenneth
03-07-2008, 10:47 PM
I followed the loom into the passengers foot well, then through the cable housing on the passengers side of the cabin, up behind the back seat and through to the boot.

Grizzly
03-07-2008, 11:49 PM
Is there enough place where loom enters cabing for a cable of good size?

To be honest, I've never yet seen left side of the car with fender removed :(
If someone has foto, pls, post

Kenneth
04-07-2008, 12:28 AM
Is there enough place where loom enters cabing for a cable of good size?

To be honest, I've never yet seen left side of the car with fender removed :(
If someone has foto, pls, post

You can see the orange cable in this pic. There is plenty of room for the cable.

attachment.php?attachmentid=19992&d=1195443663

Grizzly
04-07-2008, 08:43 AM
Thanx for the photo, Kenneth! It's of big help to me :)

Turbo_Steve
06-07-2008, 01:03 AM
Kenneth, maybe it's a bit more temperate out there, but in the dead of winter in the UK, when it's hissing down with rain and you've got the heated window, mirrors, seats switched on, headlights on, all fans going and the stereo blasting (just a headunit, mind! I'm not talking amps or anything crazy) we'll find that coming to a stop at junctions without a battery can have all sorts of weird effects...dash needles bouncing about the place, engine running like crap etc etc.

Whilst I agree with your sentiment on cable size, the "no battery" thing doesn't seem to work well on jap cars.

Best way to size cable is base it on the alternator rating.

chris vr4
06-07-2008, 03:50 PM
does any1 no of any near me (croydon) that cud do this???

and roughly wot u looking at to do it???

miikka
06-07-2008, 09:20 PM
I took the cable to engine bay today. Too bad that I didn't remember take any pics of the project, I was too pissed off. Took about 20 minutes to remove fender and all other stuff, but it took about 2 hours to find suitable place to put the cable through. Huh... I've a head ache!

Kenneth
07-07-2008, 04:18 AM
I wasn't trying to imply that you should run without a battery, only point out that the alternator directly supplies most if not all of the required energy to keep the car running. Hence, not needing a huge cable.


Kenneth, maybe it's a bit more temperate out there, but in the dead of winter in the UK, when it's hissing down with rain and you've got the heated window, mirrors, seats switched on, headlights on, all fans going and the stereo blasting (just a headunit, mind! I'm not talking amps or anything crazy) we'll find that coming to a stop at junctions without a battery can have all sorts of weird effects...dash needles bouncing about the place, engine running like crap etc etc.

Whilst I agree with your sentiment on cable size, the "no battery" thing doesn't seem to work well on jap cars.

Best way to size cable is base it on the alternator rating.

Grizzly
07-07-2008, 08:24 AM
Miikka, what was wrong? How did it ended?

miikka
07-07-2008, 03:08 PM
Miikka, what was wrong? How did it ended?

Well, I just couldn't find suitable hole to put the cables through. Then I took the Dremel and cutted the black plastic "box" surrounding the wire connectors so then I was able to through the cables. Hard to explain without reasonable pics, but the one who has been fighting with the same thing should know what I'm talking about.

Here's anyway the only pic I took:
http://to.pic.fi/kuvat/VR-4/Battery+to+the+boot/06072008430.jpg

(Other 3 images in folder are pictures of taking the cable from the boot to the cabin)

Grizzly
07-07-2008, 09:00 PM
Thanks, mate :) This awaits me soon :)

By the way - nice shiny Legnum you've got :) Respect! (underhood of mine is much more dirtier - at least yet)

Grizzly
07-07-2008, 09:01 PM
Still - if someone has a close-up photo of that front door pillar where loom enters cabin, please, post

Munta
10-08-2008, 09:05 AM
found this kit the other day when doing a lil research on the task

http://www.dse.co.nz/cgi-bin/dse.storefront/489e9fce04645512273fc0a87f3b06f1/Product/View/LA3098

and because i work at dick smiths staff price is good... comes with everything needed including 200amp fuse and 5m of 1guage cable

will only need distro block and a battery box both pretty cheap on TM

Fully
11-08-2008, 07:11 AM
^hell that looks serious.

Some pics in this thread about my battery in boot.
http://www.clubvr4.com/forum/showthread.php?t=27626

Mark 4
18-08-2008, 04:22 PM
I am doing this mod at the mo. I am routing the cable beneath the front wing as in Kenneths picture. I called a local welding shop that I do a bit of business with and I am going to collect 7m of 35mm² welding wire tomorrow. £35.00 all in. If anyone in UK wants the number it's 01903 717606 ask for Ian.

Also found the table below which helped me decide.

Cable spec is 0361 TQ 35mm²

Cross Sectional Area
Loading Current in Amps for the Following Duty Cycles

mm² 100% 85% 60% 30%
16 135 145 175 245
25 180 195 230 330
35 225 245 290 410
50 285 310 370 520
70 355 385 460 650
95 430 470 560 790
120 500 540 650 910
185 660 715 850 1200

chris vr4
18-08-2008, 08:34 PM
not sure wot all that means but i have just aquired quite a long length of cable that runs the electrics on the trains /rally

just gotta sort out the other bits now and i'll be away.


if i removed the spare wheel wud the battery fit comfortably in there or isnt that recommended???

Mark 4
18-08-2008, 11:06 PM
Chris, it ain't the length that counts - its the girth ! ( and obviously the skill with which you use it ! )

chris g
19-08-2008, 02:47 PM
I did not think that size mattered at all....

miikka
13-09-2008, 05:31 PM
Okay, here's finally my way to move the battery to the boot.

Made with 2x 25 mm^2 cables, both wires has one 60A's fuse.

Here's pics: http://to.pic.fi/kuvat/VR-4/Battery%20to%20the%20boot/

Comments are welcome :)