Yep, the old civics didn't have return wires from a number of components. Adding a grounding kit was like upgrading to what the a has stock.

I agree, I mean I'm an electrician and if a customer was to run a single 120v 15a receptacle then proceed to drive a half dozen ground rods in the ground it would drop ohm readings (marginally) but is not needed for the application. But if that's what the customer wants and they got the money to do it...more power to them.

like I said it wont hurt, but the return on the investment would be negligible simply because it's overkill. I feel the same way about this kit. BUT, if a car owner wanted to do it meh its their money. In my opinion it's money better spent elsewhere. The only reason I'm doing it is nearly all my under hood caps (oil, radiator etc.) are all red with silver Z accents so it would just enhance the look. Plus hell I literally can put my hands all the components for free, all I will have in it is my time.

If the gremlins in the motor decide they like the extra grounding and throw me a hp or two all the better.

I certainly wouldn't purchase a pre made overpriced one for what you can get from a dealer though.

Alright....resuscitating this thread for recent feedback and/or experience with installing the ground kit.

From what I've read here and along with other web searches, the majority opinion is that the kit has no effect on actual performance for AT. I already have AAM mid-pipe with short tails and Stillen Gen 3 installed and waiting for the FI HFCs I ordered. After the HFCs install, I plan on doing a dyno tune, so do think it's worth it to install the ground kit?

Unless you have reason to believe the factory grounding system has been damaged, I wouldn't mess with it.

If we were talking about a car from the 1960s, wiring/grounding improvements might make some difference. In a modern, computer-controlled car, the engineers are more careful. The factory wiring seems to be just fine on the 370Z.

Ie, if it ain't broke, don't fix it.

But beefing up the wiring won't hurt anything (assuming it's installed right). If it will make you fell better, go for it.

I used to think it was pointless , but we have noticed a reduction in electrical "noise" when fitting an earthing kit to 350z's, whether there is any tangible performance benefit I dont know

A wise man once told me when I was drag racing that you couldnt have too many earths

DIY kit - cheaper route - cosmetic - but did see a change
 

So this past weekend I took the time and built my own grounding kit and found that there is a slight - and I do mean slight - change in the car.
After careful research here on the forum and weighing all the Pro's and Con's and yes, even the positive inputs and negative trashes, I elected to do this mod. What I found was the other available kits at 89.00 and up are really only scratching the surface. Let me cover the details for everyone A to Z....

I had been experiencing hard shifts and weird upshift and "pause power" delays in throttling during the last 4-5 weeks. So I figured what the hell - Right?

Now I can't really speak for Stillen's kit, or any other kit for that fact. I built up my own using Stereo shop relationship and price trolling via the WWW. But I have seen a change in this car and it is definitely noticeable. I also believe that since the car was bought used - I know the previous owner took cosmetic care of the car, but really ragged on it via throttle and driving hard.

Personal build:
1. Get a 4 or greater connection point battery terminal clamp. Gold Plated.
(I used a Stinger 4 point with 2 4ga and 2 8ga connections) $9.99
2. Got 30ft of 4ga COPPER - OXYGEN FREE! - only wire
(have a friend at local stereo shop - so got wiring for a deal) $30.00
3. 20ft of 8ga COPPER - OXYGEN FREE! - only wire
(same deal on wire listed above) $15.00
4. Got all the 4ga and 8ga gold plated crimp eyelets from his shop $10.00
I also had a few 8ga stainless eyelets in the garage.
Also had soldering iron and higher grade RC solder on hand.
al said and done was at 70.00 in all spent.

Step A: I took 2 8ga connections from battery terminal to Throttle bodies.
Step B: Then I took 2 4ga runs from battery and have one to the front of the engine block. The other goes down below to tranny housing near engine bell.
Step C: Added runs to the rear throttle positioner and the other ground points in the engine area from the front engine ground points.

Now I also scuffed the metal on the engine block points and also on the Fender points. Then took the points and gave them a "meshed - ring" type of interconnection through-out engine bay.

I've given pictures to give the visuals for everyone - but I have to mention that the kits online never had a connection going to the cam throttle positioner? at back of the motor and also to the Transmission itself. The part on the back of the engine is the part that took the car down for a week and a half running it in safe mode when gassing it.....

Since I made all these connections and added some points that the kits do not have on their set ups - I can honestly say I have seen a change in the car. Snappier launches and a heck of an improvement in shifts up and down while in traffic. And there is absolutely zero electrical noise showing on the scope now - or heard through the speakers.

I do agree it is really a cosmetic mod - and really for looks. But I got to be honest - I saw a change in my car and I honestly thought I wouldn't.
There was some corrosion or build up on the terminals and points that saw moisture. So in effect I had a dirty ground in the car's system. My purpose was to get some cool looking red wire up there to go with the rest of the upcoming mods. So my opinion is 75% cosmetic and 25% function - and that is if you have a car that saw moisture or had corrosion or loose grounds.

Just thought I'd share this in case anyone see's they might be shifting erratically in traffic, or have hard thunky shifts or just see that throttle void or lack of torque once in a while.

Week after next the Level 10 components go in. Then I'll see if there is any more change other than the obvious - LEVEL 10 v-body and Torque conv.