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Making / Installing your own Groundwire Kit
by Wil Fellows (Gro Harlem)
Applications: Universal Estimated Time: 1.5 hours

What is a "Ground Wire" kit?:

A newly found modification that works on nearly any car. A groundwire kit typically consists of about 5 wires which you connect to various places under the hood to improve the ground connections. These wires are basically 1400-1700 strand, 99.9% copper car audio power wires with 24k gold-plated ring terminals.

How does this benefit my car?:

More strands of wire translates into less resistance which translates to more effeciency. And with the thicker wires, you also ensure your power-hungry components are grounded as best as possible. With more effecient grounds, your engine will see less parasitic loss via the electrical system. Most new cars still come with barely adequate ground cable's and usually consit of 8-10 gauge cables made of less effecient material. These cables often have only 200-500 strands.

What can I expect to see by installing these?

Many magazine's have tested these Ground Wire kits on various models, all of which saw some kind of power gain. Anywhere from a 2-15whp peak gain in the recent Import Tuner article. Of these cars, the average gain throughout the powerband was about 2-5 whp. You can expect a 2-6whp peak gain if you own a 1.6-2.2 liter 4 cylinder car and at least a 1hp gain throughout the powerband, and maybe more.

On top of that, you will notice increased throttle response due to a better spark, brighter headlights, and your stereo system won't strain your alternator as much as before (ie: less headlight dimming when the bass hits).

You should also immediately note a smoother idle when you first start your car.

What aftermarket companies Make this kit?

The Import tuner article tested the Sun Automotive "Hyper-Ground" wire kit which consist of 5 wires which are connected in a "daisy chain" setup. Sun Automotive patented this form of connecting ground wires which no other company can mimic. This kit comes in 5 colors and sells for $104-120+ from Sun Automotive.

Arospeed makes a kit with 5 wires which uses a distribution block. You string the wires to various parts of your engine, and the distribution block is connected to your negative battery terminal. This kit sells for about $60-80 and comes in red, yellow or blue.

HKS sells a "Circle Earth" kit which is also a distribution block style kit and includes 8 wires total, but the wires are 8-gauge. This kit sells for $120-150 on many websites.

Details about this installation:

These pictures reflect the install of a "daisy-chain" style setup on a 1993 Mazda Protege LX. Where you place your wires is up to you. But for the best effeciency you should at least have a wire on the right chassis, negative battery terminal, left chassis, and intake manifold or engine head.

Tools you will need:

  • Basic wire-stripper / Crimping tool (it does NOT have to be a 4-gauge crimp tool. My 10-12 gauge crimp tool crimped the 4 guage terminals just fine)
  • Ratchet or wrenchset (I used a 10 and 12mm socket with a ratchet to undo the bolts for the ground kit)
  • Knife or decent pair of scissors (can use to strip the wires, and to cut them, but not required)
  • Sandpaper to prepare grounding surface.

Parts you will need to buy:

  • 9-14 feet of 4-gauge amplifier power wire. (Color doesn't matter and is your choice). It is usually cheaper to just buy a 4-gauge amp kit off ebay. They start at about $20 shipped depending on which brand & seller you go with. Mine cost $28.50 shipped and used blue power cable and silver groundwire.
  • 2 4-gauge terminals per Wire you are going to install. I used 12 total, but purchased 16. You will want at least 10 since 5 wires is what most of the kits seem to come with normally. These range in price. I bought 4 sets of 4 platinum-plated Stinger terminals for $3.75 per set plus $4.50 shipping which totalled $19.50 shipped.
  • Gold plated car audio battery terminal. (Preferably with 1-2 4-gauge inputs so you can link even more wires off of it.) It is your choice to buy one of these or not. I knew I had one at home, but I was in college when I did this install hence why I didn't use it. These are on ebay for anywhere from $12-20 shipped for a basic terminal.


Amp Kit and 4-ga. Terminals I purchased

Decent quality Dual 4-ga. battery Terminal


Installation Instructions:

1: The first thing you will want to do is determine where you are going to connect your ground wires. I decided to do mine like this:

My right chassis connection would be on top of the cruise control bracket. From there to a bolt on the Intake manifold. From the intake manifold to the engine head where the distributor mounts. From the diistributor I split off two wires, One went to the transmission and the other to the airflow meter. From the airflow meter I ran a wire to the negative battery terminal and from the battery terminal I relocated my left chassis ground to the bracket holding the ignition coil in place. I did this to increase throttle response via better spark and better airflow meter performance. (and it worked). See below to see how I connected

2: After you have decided where to string your wires, string some of the 4-gauge wire from the first mounting point to the second. Cut the wire to legnth and strip both ends. It is somewhat difficult to strip such thick gauge wire. I used some scissors out of a swiss-army knife to cut into the plastic covering and then I just ripped off teh remaining plastic and threw it aside.

You only need to strip expose about 1" of the copper wire. Don't expose too much or it will interfere with the crimping.
3: After stripping the plastic covering off of the wire, place one of the 4-gauge terminals onto the exposed wire

4: Although there are 4-gauge wire crimpers. I wasn't about to dish out $38 for one from Lowes just for this job. I already had a $6 crimp tool, and I found the 10-12 gauge "non-insulated" part of the tool to crimp these terminals on the wire pretty well.

Make sure your first crimp is in the center of the terminal.
Here is a picture of how it looks after the first crimp

5: After crimping the first time in the middle. Move to the "insulated" crimp part of your tool and crimp both above and below where you initially crimped to make sure the terminal won't come loose no matter what.

My terminals were pretty easy to crimp, but some 4-gauge terminals use thicker metal and may require you to crimp both sides of the terminal to ensure it won't come loose.
This is how the terminal will look after all 3 crimps.

6: Now slide the rubber cover things (most terminals come with these) over your terminal and cover the exposed wire and crimp as best you can.

As for what color to choose, you will have half red and half black rubber covers. I decided to use all of my black covers for the areas that you would be able to see, and use red ones on connections that won't be seen by most people who just glance under your hood.

It is up to you to decide how to connect these

7: Repeat steps 2-6 until you have all of your ground wires cut and with terminals crimped to every end of them.

This picture illustrates my connections backwards. The wire on the far right is my right chassis ground to intake manifold wire, then the intake manifold to engine head. Then the engine head to transmission wire. Then the engine head to airflow meter. Then comes the airflow meter wire to negative battery terminal. And finally, on the far left is the negative battery terminal to left chassis ground.

8: Now that you have all of your wires cut....remove the first bolt on your right chassis. Most bolts are usualy 10mm in size but some are 12mm. This particular one I removed was a 10mm.

Take the peice of sandpaper you have and sand down the area around the bolt where your terminal is going to contact. If you are grounding to a painted surface, it is better to sand away the paint and expose bare metal. Brush away any dust or paint shavings and tighten the bolt or nut on top of the terminal.

If you sanded away too much painted surface, you can always touch it up with some touch up paint if you want to keep the install as clean as possible.

9: Now that you have your first connection done, route the first wire out of sight as best as possible (unless you don't care) to the 2nd connection point. Grab your second wire and connect the 1st wire and 2nd wire to the same connection on the intake manifold (or wherever you chose to mount your second wire).

I had to sand away some corrosion caused by road salt when I removed this 12mm bolt.

10: After routing your 2nd wire out of sight, grab your 3rd wire and connect it to somewhere on your engine head. I decided to use the 12mm bolt which holds my distributor in place. I figured this would help ground the ignition as best as possible and provide a better spark.

Notice how I didn't connect the transmission wire to this bolt. The only reason I didn't is because i couldn't fit all 3 4-gauge terminals on the one bolt since the thermostat got in the way for the transmission wire.

Here is a picture of the other distributor mounting bolt. I figured it would trasnmit just as good a ground.

11: If you decided to split your engine head ground off like I did, find a good bolt on the transmission to ground to. I used a bolt that was already used to ground a couple of things.

Your bolt will most likely have quite a bit of corrosion and build up, especially if you own a older car like me. Just sand it away as best you can.

12: Take the 3rd cable connected to your engine head, and ground your airflow meter (or whatever you want). Bolt your 4th cable to this same connection and route it to the negative terminal on the battery. You could if you want just ground the 3rd cable straight to the negative battery terminal, it depends on how many wires you made.

I decided to ground to a nut that used to hold my airflow meter to the airbox. Since I have a custom intake adapter and cone filter, this stud was no longer in use by anything.

Your airflow meter may or may not have a threaded bolt or stud that you can use, if this is the case, find something else to ground, like your ignition coil or fuse box.

13: Connect the cable you routed to the negative battery terminal. If you bought a new terminal, just use it instead and remove your old negative terminal and wire and throw it aside.

Since my terminal is 200 miles away, I decided to postpone installing my terminal until I come home from college. I chose to use a spade connector for this end of my 4th cable which made the connection easier.

Do not connect the 4th wire's terminal in the middle of the Negative Battery terminal! This could cause the terminal to not clamp down on the negative battery post hard enough to create a good enough connection and can potentially cause your car not to run.

14: Finally, connect the 5th wire from the Negative battery terminal to anywhere on the right hand side of the chassis. The best places for this would be near the fuse box, strut tower, or ignition coil (if you have an external one).

I chose to connect mine to the bracket holding the external ignition coil. I figured it would help throttle response.
Here is a picture of all 6 of my wires installed! I did my best to hide them, but you can still see them if you look for them.

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