I was skeptical about doing this but I'm glad that I did. The stereo has a cleaner sound and the 1-2 shift is improved in manual mode. The improvements are subtle not dramatic. I got everything I needed at a local electronics store for right at 20 bucks. This is one of the most clearly written, easy to follow DIYs I've ever seen.

 

If I were to use 4 gauge wire, would I then use 2 gauge terminals when two wires come together?

Also, where are you guys getting inexpensive wire?

Sorry, I don't know anything about wiring and google can't tell me.

 

Yes a 2 gauge terminal should be sufficient for two 4 gauge wires (Depending on the quality of the wire and strand count). If you want to be safe go with 0 gauge terminals.

In my honest opinion 4 gauge is OVERKILL for this application. 8 gauge wire is more then enough you wont see any difference between the two. You are throwing away money for the thicker wire.

Just my 2 cents!

 

^^^What he said^^^
I found the wire and terminals at a local electronics surplus joint. I paid 95 cents a foot for 8GA wire, 60 cents a piece for 8GA, and a buck a piece for 4GA gold plated terminals. It took me about half an hour to make the wires up and about the same amount of time to install them. The most difficult thing was getting the ECU to reset.

 

Thanks for the replies. I'll stick with the 8 gauge then.

 

I need To try this!!

 

I finished putting these on today.
My experience was that the longest segment from the third wire as well as the second wire were both like 6" too long. I recommend using some string or rope between attachment points to verify before you cut.

I also added a leg to the second and third wire and ran that to the throttle bodies.

 

Should we have a ground wire going to the transmission (for 7AT)?

 

Great DIY...Made and installed a set this past weekend. Used black wire instead of red to blend in with existing wiring (more of a factory look). Also adjusted the lengths to tuck / tie wrap in certain areas. Prior to installing the kit (1) other person as well as myself took a "spirited" drive and another "spirited" drive after the installation...we both agreed the shifting (or lag) between gears was indeed improved. Overall def impressed a $35 DIY would work this well. Thanks again...Much Appreciated!!

 

^+1....... I also went with black wire and black gold plated terminal rings for the stealth approach. I will be installing this weekend. Even if I see no difference in the shift lag I only invested $22.

 

Thank you for this DIY post! I just finished mine tonight using Stillen grounding kit. Will check it out tomorrow for difference in the shifts

 

So I realize this is my first post, and I'm honestly trying to be constructive, but I'd like to inject some insight into this DIY...

I'm an engineer, and a car audio nut, so I'm used to working with electronics, cars, wiring, modding, etc. I would never say never without knowing the whole story, but I have to say I'm not sure how the heck this would make any difference. That said, so many people know it does so I'm intrigued.

In the audio world I see this type of upgrade done all the time to get better current flow through the factory system and that DOES for sure help an audio system that is limited by the factory grounds which were only designed to handle a smaller amount of current then an aftermarket system typically asks for. We don't even think about doing what we call a "big 3 upgrade" until we add 1000 watts in amplification to a car. However, who knows, maybe Nissan messed up the factory design and just under grounded the heck out of our cars.

I don't want to talk about how it can or can't, does or doesn't work... I just want to help this DIY be way more cost effective and easy to install.

The way the original poster shows to do this there are 9 connection points, 1 at the battery going to the body, 4 at the body going to the engine block, and 4 on the engine block.

Battery to body...

Great... lets get good solid juice to the body and everywhere that has a ground will benefit from less resistance and therefore less voltage drop.

The body to engine block...

1 to the engine block, great. Get it as close to the alternator as you can to get the most direct path where you need it. More than one going to the engine block? I don't understand. The engine block is a HUGE chunk of metal and in no way would benefit from multiple connections. The body as well is known in the audio industry as a 4 gage connection to anywhere. Running multiple connections to it would have very miniscule effect if any on voltage drop.

One more thing...

Run a 4 gage from the power on the battery to the 12v output on the alternator. This makes sure you have the other side of the circuit fully taken care of.

Those are the big 3. We usually do it with 1/0 gage wire which handles up to 4000 watts of power. If you're putting in big audio then that's what it takes. 4 gage is plenty in our case. You can run 1500 watts of power through 4 gage w/o appreciable loss.

Hope that helps. I'm curious to try it and see what happens.

 

Thanks for your input Thumper33. The better ground improving the stereo sound is a no brainer as you suggested - just less resistance for speaker current back from amp to the battery. But I think one part of all this that is key (I am a computer guy - 30 years) is noise on the ground plane the farther away from the battery negative post you are. There are many sources of high voltage spikes and RFI interference in our cars. Spark plugs & coils, alternators, and static electricity even. The various components of the cars sophisticated ECU and microcontrollers throughout the car communicate on a bus called the canbus. These communication channels have built-in error correction and will re-transmit as necessary to make all communication intact and complete. When there are noise spikes on the canbus due to noise on ground, the error correction software takes over and does what is needed. This can cause small time lags in this canbus commmunication. A cursory glance at the G37 schematics will show many microcontrollers. Each seat has one, each door, odometer and trip, engine mgmt, tranny mgmt, you get the idea. They all talk to each other on the canbus. In addition, sensors like throttle position, transmission sensors,etc are all in reference to ground (0 volts). Having a nice solid noise-less ground floor will make everything just work better. I don't think it is about current but rather reduced resistance to the negative battery post by the grounding kit that negates the bulk of electrical noise picked up on the car's ground plane (think of an antenna). I am making up a bit of this grounding wires koolaid and drinking it myself this weekend by installing a grounding set in my 2008 G37 with 5 AT. Personally I think results will vary depending on how good your existing ground connections are. I live near the Pacific with proximity to salt spray at times and I think a good clean electrical ground is never a bad idea... Just my 2 cents.

 

I ran multiple cables to the block, but for cosmetic reasons more than anything.

I am also a car audio nut and agree with the big three. However, from what I understand, on the G, running a cable from Battery pos to Alternator output bypasses the car's charging sensor. It senses load and adjusts alternator output accordingly (apparently to save fuel). Therefore, bypassing this by connecting alternator output straight to the battery will keep the system thinking that it only needs to charge at a lower voltage and the battery will not get charged properly under load.

Someone can chime in to correct me if I'm wrong.

 

Took a stab at following this. Will install in the AM