Trunk mounted battery questions.

[Terry Posten]

What size cable are you running?

Is #2 good or do I need to go #1/0?

Where do you run the cable?

Do you penetrate into the car's cabin and into the trunk or do you run under the car?

 

[Terry Posten]

Nevermind. I found what I was looking for.

 

[fastasleep]

Youre probably going to get flamed for starting like the 6th battery relocation thread in about two weeks, but since Im a fan of your fmic setup I wont /ubbthreads/images/graemlins/grin.gif

I will be running 4awg wire from under the hood to the trunk with a 140amp breaker mounted in the trunk (as close to the battery as possible).

I think it has been determined that the best place to run it is through a boot in the front right wheel well that comes through behind the glove box. Then it just runs along the side of the car under the carpet, beneath the rear seats, into the trunk.

I have been gathering parts to do this for the past two weeks and its all going down at 2'oclock on saturday, so Ill post up lots of pics. However, I wont be doing a kill switch as I gathered it's not a safety issue; more a NHRA track legality.

related threads:

Who races at NHRA tracks with a trunk mounted battery?

what amp fuse for battery-->trunk

Battery -> Trunk, Questions unanswered

 

[fastasleep]

doh... thats what I get for taking too long to respond.

 

[turbowop]

Hell, I run 4awg just from the alternator to the battery in the trunk alongside the 2awg that runs from the battery to it's old stock fusebox location. While 4awg may work, I suggest running 2awg.

 

[fastasleep]

Now you tell me... Will fire and death result if I run 4awg, or is it just less likely to start in the cold?

 

personally i like 2awg. i ran it through th cabin along the passenger side under the carpet.

 

4 gauge welders wire here. Anyone notice the white plastic thing under the rear seat that seems like it is there for a battery wire to run through? Did jdm galants have trunk mounted battery?

 

I ran one run of 2 gauge wire from a new junction in the engine bay, through the firewall, behind the kick panel, under the scuff plates and center piller lower trim, behind the back seat into the trunk, under the trunk carpet to the battery pos terimal...oh, yeah...thats where I ran it in my Accord. But its also how I ran the new fuel pump wiring in the VR4...of course I didn't use 2 gauge wire for that.

 

[JNR]

I went with 2/0ga for the main wire to the fuse-junction thing in the engine bay...I also used it for the ground, attaching it to the strut stud, as many others have done...

IMO, it's better to be larger than you need, rather than too small..in DC applications, voltage is lost relatively quickly in length and at 15ft. or so, it can make a difference...add heat, dirty connections, etc. and the starter and such really can have a strain...Given two equal sizes, the one with more strands (i.e. welding wire) will outperform the regular wire and 'solid' variety...grounds and clean connections are critical as well and you can never have too many...

I ran mine thru the back seat opening, under the rear seat, under the carpet near the rocker area and up thru the factory firewall, where all the ECU wires run (tricky to get thru, but it worked)...it's like it was made for a remote battery!

These cars seem pretty forgiving though with battery in the trunk...in my Chevelle, with the batt. in the trunk and the pass. header primary like 1/4" from the starter solenoid, let's just say I had many issues with starting (even with 0ga, starter relay and finally a remote solenoid) /ubbthreads/images/graemlins/grin.gif

 

[fastasleep]

My back hurts, and Im too tired to write, so all you get are pics for now...

/ubbthreads/images/graemlins/wink.gif

 

[Hertz]

A+

Ready for the intake now? /ubbthreads/images/graemlins/smile.gif

 

[curtis]

I'm not bashing or talking poop but when running the battery to the trunk also run a ground back to the front of the car and run extra grounds to the engine. If your not running problems great but not having the engine grounded properly can cause weird problems in driveablity and performance and also the wallet from extra gas used. If any of you have ever ran one of the extra ground wire kits you understand because with the last 3 ground wire kits I made for my own cars I picked up some extra mileage per gallon. My Honda passport picked up the best with almost 2 mpg on the interstate. The reason is that the manufacturers don't seam weld but spot weld and puddy the seams which causes a higher resistivity. Some cars are worst than others. Mustangs are notorious for running like sh*t when this is done. The injectors and all the other electrical garbage on our cars pulls a lot of amps and the extra grounds just makes life easier on all the components. My dos pennies.

 

[iceman69510]

I have done it both ways, but have had no problems in my current Galant with the - cable grounded in the trunk. All factory grounds are in place in the engine compartment.

 

[fastasleep]

Quote:
A+

Ready for the intake now? /ubbthreads/images/graemlins/smile.gif



Yes, but it doesnt want to fit /ubbthreads/images/graemlins/frown.gif click

About the grounds, I have about 18ft of 4awg wire laying around that I would love to put to good use. Does it help to replace the grounds with thicker gauge wire, or is the solution to create more of them, or both? Is there a diagram that shows where all the grouns are located on our car? I can only think of two (one from the intake mani --> firewall, and one that branches off the factory battery ground).

 

Here is similar but different approach. Have had no problems with grounding in the trunk.
Mike R.

 

[boostx]

i was wondering about the grounding and the spot welds , i am going to use 2 ground on mines

 

[turbowop]

My battery is only grounded in the trunk and has worked fine for years now. The car also gets 25+ mpg to boot, when I'm not romping on it.

 

[fastasleep]

I have another question. My aluminum box is sealed, but it has a breather line that vents out of the side. Does that have to go out through a hole in the bottom of the trunk, or can it vent into the trunk itself?

 

[turbowop]

For NHRA legality, it needs to vent to the outside of the car. The techs at my track have never looked for it, so I haven't installed the vent yet.