Trunk Mounted Battery + Rear Firewall - routing battery cables, feedback wanted

[1969CamaroRS]

Trying to figure out my entire electrical system before I start. I'm moving my battery to the trunk. I'd also like to install a rear firewall (see attachments for some examples I have found).

But I am thinking instead of welding the firewall permanently, bolting it in and using weather striping to seal it up. It also looks like to me if create a close out that bolts in from the trunk side it will be easier to get a single piece to lay flat (since the passenger side has a lot of bends in it especially around the wheel wells).

My question I still have is how to best route the thick battery cables I want to run up front. I am going to be running a Ford solenoid so that the starter cable is only live during cranking. So I will have 3 cables I need to run (Starter - 0000ga, B+ 2ga and Ground - 0000ga).

I am thinking maybe just using the same firewall bulkhead connectors might be the way to go:


Any ideas on standard 3/8" and 1/2" eye lug terminal covers for use on the above bulkhead connector?

Another possibility would be to cut out a small corner of the closeout and route all the cabling through there (adding something on the edge of the closeout to protect the cables). Wont be sealed but still should provide some protection.



My biggest problem is I don't want to buy a huge 0000 battery cable crimper for just a 1-time use on these cables (at $300+), so I found a place that will make custom ones but that makes running the cables through a wall more difficult since I'll have assembled cables.

Any feedback or ideas on the above is greatly appreciated!

[rossmacd]

There are schools of thought regarding battery cable routing, and they usually revolve around a budget. Will running a 4o ground to the engine block impove grounding? Yes. Is it worth the expense? Probably not. I would (and did) just run my ground from the battery to the framerail and call it good. Make sure you have an equally large cable from block to ground, and you are golden. I get 13.3 volts or so, using this method with 2o WELDING cable. Strand count is in the 1300's. That alone was worth 2v over my old Summit 2ga (or whatever) cable. Also, I go all my lugs, and lug covers, from McMaster Carr. Very reasonable prices. They also had solderable lugs, which aleviated the need for a crimp. That, plus adhesive lined heat shrink makes for a great connection. You don't have to worry abot cracking with battery terminals the way you do with smaller (i.e. 12 g) wire. The cable is heavy enough and strong enough that it doesn't really vibrate. You can buy crimpers for like 30 bucks or something that are practically just a punch, but they aren't great. At least that was my experience.

As for the trunk divider, why do you want to run one? Is it to conform to some class rules? If that is the case, you need to find out what they say about things that pass through that firewall. If it is because you want to and you think they are cool, then I wouldn't hesitate to run those bulkhead connectors. But I wouldn't leave a section clean so the cables can run through; one, it defeats the purpose of the firewall, and two, it porvides a point where, theorhetically,the cable could wear.

Alternatively, you could run it through the trunk floor and under the car. But that of course has its own problems.

[smhigh]

I have my battery in the trunk and a ford relay.
I ran the + cable to a bulk head connector and then the starter.
I have the - cable going to the sub frame in the rear and a matching heavy cable from the front sub frame to the engine block.

I used all the GREAT information from MAD Electrical

http://www.madelectrical.com/index.shtml

They have everything you need to do the wiring correctly.

http://www.madelectrical.com/catalog/tm-1.shtml

[19sixtynine]

x2 on MAD electrical

a wealth of information and top quality parts. He also has how to instructions on how to crimp 0 gauge wire without buying any special crimping tool, along with a ton of other instructional pamphlets.

[CarPlayLB]

Ed,
I am in Long Beach and I can crimp the ends for you! I also have some 2/0 welding cable, 1300+ strands that we can make a deal on! (and a LOT less than $300). I have been making my own cables for years. I have heat shrink to seal the ends so there will be no corrosion issues.
PM me when you have a chance

[1969CamaroRS]

Hi CarPlayLB, must have missed your response. Thanks for the offer, but having some custom 4/0 cables made to length.

As for the trunk divider, why do you want to run one? Is it to conform to some class rules? If that is the case, you need to find out what they say about things that pass through that firewall. If it is because you want to and you think they are cool, then I wouldn't hesitate to run those bulkhead connectors. But I wouldn't leave a section clean so the cables can run through; one, it defeats the purpose of the firewall, and two, it porvides a point where, theorhetically,the cable could wear.

Alternatively, you could run it through the trunk floor and under the car. But that of course has its own problems.

Mostly to give some protection in case of bad re-end collision from fire entering the passanger compartment as fast due to fuel spillage.

------------

This what I ended up doing (mocked up still gotta paint my floors and closeouts):


With bulkhead connectors installed (for B+, Neg and Starter):


Not perfect but will get the job done. Mocked it up first via some carboard to get the patterns till I could get it to fit nice, then used the cardboard patterns to draw n the 18g CRS sheetmetal. Then cut the patterns out with my cut-off wheel.

Once I get the battery cables I can mock everything up then once everything is set, see about painting everything.