batterycablesUSA.com has great prices on welding wire, which is way better than amp wire. I got my entire setup red and black 2 gauge (12' each) battery terminals, 2' of adhesive lined heat shrink for like $80 shipped. Welding cable is usually more flexible than amp wire as well.

 

Not pictured: the mount for the cutoff.

 

+1. I buy all ground and battery wires from a local welding supply store, it is good stuff.

 

Question on grounding points. Saw video by DNA garage recently and the owner was talking about how the ground wire after a relocation needs to go back to the engine. Said he went to a wiring/electrical class and that it was hard to explain, but when grounded to the chassis in the rear it will start. But to make everything run better and eliminate noise it needs to go to the engine.

This isn’t really something I have seen in all the other battery re-direct threads nor on a standard google search for other vehicle re-directs. Not sure if it applies more to the RX7 because of its noisy ground issues or standard across automobiles.

Unsure if he meant engine bay or the block itself...? Anyone have any experiences with this (is no electrical expert).

Also are there any issues with running a ground wire and power wire next to one another? For example I know you do not want to run power wire by signal wires if you can avoid with audio systems.

Standing by for any gouge!

-milly

 

The trick with signal and audio is to have shielded wire or twisted pairs. The audio wires in the RX7 come twisted, and important things like ignition, and knock come shielded

The trick with the ground system is to have CLEAN contacts, and ensure the grounded parts are connected so it actually grounds (and possibly a shot of clear coat on top to protect from crap). Big ground loops do little more than just add weight, defeating the purpose of using the body and engine as grounds. Using the engine is a way to "shortcut" and not need to run big ground straps all over. Using factory ground points should be fine, as long as they are clean and bare contact. For peace of mind you could run two really good grounds from the battery, one to engine and one to body. Then clean all the contacts in the remaining factory ground points.
The engine harness directly connects the battery to the engine, so I can see their thinking, and it lines up with what I said about 2 good grounds from the batt. It's also a small car so not too difficult to run a ground along the fuel lines to the engine.

On my WRX, I did have the Apexi super ground kit with voltage stabilizer and the batt moved to the trunk. Without the stabilizer voltage was a mess, sometimes not even high enough to start. With it on, it held a constant 14.5V the entire time.

 

b3delta,

Thanks for the reply. So essentially as long as it is done correctly either way is good 🤷‍♂️ Haha. Most likely going to ground it to the chassis and make sure to clean up all the other grounds. If I notice a difference, I’ll just run a longer ground wire as a test to the engine bay and see how she looks.

Thanks again,

-milly

 

I recently installed one of LRB's battery trays behind the RHS seat. I had already ran a positive back to the stock positive fuse connector, and made a ground connection nearby. I also ordered one of Pettit's free ground "kits" which connects to both the block and the chassis.
What battery brands are you guys using these days. It's been suggested to me to go with Odyssey over the Red Top. They dont seem to be very far apart in price, either.

 

I put in a red top when I first got my FD, they're reliable but quite pricey and heavy. I'll be putting in a PC 680 and I'm considering adding a super capacitor inline as a cranking backup, but not for sure on that. My build is very minimalist so I don't need much power wise, just enough to start the car, the 140A alternator helps as well.
I also rebuilt the fusebox and everything, so it's very different from the OEM

 

I’m leaning towards a Braille battery setup. Little bit more than the PC680 and much smaller to easily fit in the rear bins. They’ve got a few different models in that compact size range. Super capacitor is not a bad idea. May do that down the road if needed.

-milly

 

brailles are crazy expensive, can usually buy the equivalent Deka. They're the same thing - like buying an Escalade or a Tahoe.

 

Unless I‘m not searching correctly I cannot find the same size and power Deka battery any cheaper. Braille has batteries only $30-$60 more than the PC680 that have more power and are smaller.

 

IDK there's lots of choices and differences. Dekas don't come with terminals, Brailles do, Dekas are rated in CCA, Brailles in PCA, there's a difference, There's also newer lithium batteries, but they're much pricier and need a charger if it's not daily driven. Voltphreaks makes some insane $1100 batteries. Hell any battery should be fine as long as it works and holds charge, I haven't done much research yet but I'm hoping the super cap can help with it as well.
An ETX14 Deka is about $93 plus shipping and terminals, the equivalent Braile B14115 is $178.49 plus shipping
If they are indeed the same as the entire internet claims, then it's likely there is some factor besides just a name where they can get away with such a price difference, like quality control, how often robots are calibrated, or the materials used. I'm a bit away from purchasing for myself so I'm going to continue to look and stuff - for now I have the red top and a crappy mighty max battery from amazon which I use to bench test electronics like my PLC
Deka ETX14 Power Sports AGM Battery
https://braillebattery.com/collections/lightweight-agm

 

Fair enough! May just have to give her a go!

 

From an electrical perspective, the reason you might want to run a ground cable instead of using the chassis is because of spot welds. The car's body/frame/chassis is not a single piece of metal, it's made of multiple panels that have been attached together. The individual panels might have enough metal to carry electricity well, but the spot welds where they attach weren't built with the intention of carrying enough current to run the starter.


Also, thanks for the link for the ETX14.

 

Found the same battery on a few other sites for cheaper. Ultimately found it on Amazon for $78 and free shipping. Figure if there's any issues, easy to track orders and resolve them with Amazon.


-milly

 

Good point, I didn't think of that. Could almost bond the chassis with many super short jumpers connecting the pieces together, instead of running a longer cable from here to there, Or add a second ground connection with each harness to "stitch" the car together.
Many people also don't mind the extra few pounds for a longer ground loop, as it doesn't even add up to the weight of the air pump, and/or the weight you shaved with a smaller battery. There's also the material used. Battery cable, welding cable, or even those uninsulated braided ground straps. To each their own and there's more than one solution.


Such a good forum, actual discussion instead of flaming. NASIOC was a nightmare if you weren't a "certified" Subaru "mechanic".

 

The mount I posted above, and the wiring have been absolutely great so far. I ended up running 2AWG cable from the battery directly to the starter. I considered running a ground to the factory ground location, but decided to go another route first, and add a full length ground if it did not work out. I used 0AWG wire to ground under the drivers side hatch strut after removing the pain on the body and the hatch mount itself, cleaning the threads and using new hardware. This only spaced the mount from the body by about 2mm and didnt create any clearance issues. My thought process was, not only will the cable contact the body, the two welded on nuts for the hatch strut will provide a path for ground. I topped it off with clear coat to prevent rust. Comparing my rear mount vs using the factory connections up front, I picked up ~30 cranking rpm with the same open battery voltage.

 

Had a Braille and then a Deka battery in the rear bin. Both were horrible, and each kicked the bucket within a year. Switched to an odyssey and it’s been an excellent battery (other than the tiny terminals being fragile).

 

I have a Odyssey in an LRB relocation tray. I like the battery, but HATE the terminals! Why the hell are they slightly conical?? Anyone know of any cylindrical replacements?
I also strongly recommend running a ground back to the block! I currently have a main ground to the chassis nearby the rear bin, and another along the door sill where I also grounded my ECU. Im going to follow my own advice and run a ground to the block very soon. FD chassis grounding is a fool's errand.

 

I would also agree with running the ground back to the block or the original location. Using properly gauged wire is also very important.