^^ thanks..you beat by a minute so i didnt see your post when i posted mine.

 

Funny, I'm planning on doing this myself this weekend.
I'm getting a bunch of 4 Gauge and some ring terminals
from my dads work.

 

Grounds on a cars system need to be at a maximum of .05V potential to maximize performance and reliable readings ... so grounding is very important (one loose connection raises that potential ) ... now the one here may have gone a bit to extremes... but there is some merit to it. But if he is adding a high end sound system.. there is much more merit to it.

 

In my humble opinion, you only need 2 ground wires, one to the alternator/engine and one to the chassis. Anything more is a waste. Electricity uses the path of least resistance. It's not going to utilize the long runs of wire from one side of the engine bay to the other. It would be best to beef up the two stock grounds to a larger guage and not worry about running spaghetti all over the engine bay.

 

I'm sure this is a stupid question. Then again they say there are no stupid questions, but hopefully there are others out there who have less understanding like me, so what I don't understand is how you know where to ground the wire? I mean, you don't just ground the wires any old place right? There's some rhyme or reason to it, correct?

 

In a way you are right.. but not totally... the LARGEST amount of current travels the path of least resistance. In a parallel circuit each legs voltage drop is equal, meaning that there is some amount of current in each leg as long as there is sufficient potential (no shorts that fry the source). That is why if you place a 4ohm speaker in parallel witha 2 ohm speaker.. your total impedence is 1.333 ohms. Current travels through each coil, only more travels through the lower impedence. So if you have a device that is grounded to the chasis or block at 5 feet (circuit length) from the nearest ground as opposed to one that is half a foot to the nearest ground, you are going to have more ground resistance on the longer path... wires and metal do not have zero resistance (unless of course they create a perfect superconductor). So if you add a second ground path, you effectively have a parallel circuit to ground, providing less overall resistance. Now how much these extra grounds effect performance is still up in the air without measurments...

 

On the face of it, it sounds ridiculous to be tying the grounds of various pieces of car electrical equipment together with an earthing kit, since, as you so nicely pointed out by definition they're all tied together by the chassis of the vehicle.

However, it's not so stupid when you consider the lousiness of the earth connections that various devices may have to contend with. Most notably, the battery itself in many cars often has less than perfect clips on its terminals - corrosion is common between the clips and the wires that're crimped into them, thanks to the proximity of sulfuric acid. And other things can have bad earth connections too, if there's rust or slight looseness. The connection may look OK when you apply a multimeter to it with the car stopped, but may become unreliable when the engine's running.

High end Auto audio, the ECU and their networks of sensors are the issue; they fail to operate properly if their design assumes a clean 12/13.8V supply but they actually get something glitchy and fadey. Any well designed electronic device should be immune to all normal power input weirdness and of course the automotive industry's been using electronic control systems for long enough now that they ought to know what their gear is likely to be fed. But then again, these things are built down to a price, and even in performance cars a percentage point or two of engine power is going to be very hard for the user to detect, even on the drag strip. So, it can save the manufacturer millions to not bother. If that's all the car makers sacrifice by not running their own fat earth cables all over the place, they may be perfectly happy with the situation. No harm, no foul to them and you don't know the difference.

For this reason, I find reports like this one, which found a massive 1%-or-so gain in peak dyno power with an earthing kit, plausible enough. The complexity of the engine management system, in a modern tweaky performance car, is sufficient that improving the earthing may well actually do something.

http://www.350zforum.com/tech/groundweb/groundweb.aspx

 

You just blew his mind

Check out the link. This guy really did a fact finding dyno test.

 

Just a smoother idle and better throttle response is good enough for me. Plus it looks damn good.

 

.[/quote]

You just blew his mind

Check out the link. This guy really did a fact finding dyno test.[/quote]

Wow.. actually more of a difference than I thought it would make (not stellar, but a measurable difference). That difference will probably show up more down the road when connections start to deteriorate. Actually, they wont show up more... the effects of the two stock grounds deteriorating will not show up as much. Great link ScionDad! And sorry again to everyone for writing a book on electricity on here.... but how often does one actually have a change to discuss such things?

 

For a $20 mod....Not bad at all. Yea, like jmiller said, it looks great too.

Oh, it's information like you gave that removes the rumor crap and applies facts. Good job. Not to mention it's great to read something that's not BS.

 

That's my humble opinion too. Toyota electrical systems are very well designed and most do come stock with good ground wires from the right strut mount to the plenum and engine block. The sensor and injector grounds are on the back of the plenum. Don't see anywhere that would pose any resistance. It seems that some judicious voltmeter probing could prove or disprove this theory quite easily.

 

First off, I'm not knocking anybody for what they choose to do with their rides. I think it's cool to try new things and share our opinions witth each other.

I beleive this thread started out talking about an xb. That means if you do get the 1% gain on a dyno, you are gaining ~1 hp. I challenge you to blindly drive a car with 108 dyno'd hp and one with 109 hp and tell which one is which. Now for some people here, I realize that hp is everything and you will do whatever you can to get the most out of your motor and that's cool. No harm done there.

As for these home made grounding kits, I have yet to see someone say why they placed a ground point in a certain spot. It seems to me that it's fairly random. If it is random, then there is no point in doing it other than the hope that you might get a gain somewhere.

If you are worried about the ECU ground, run a better ground to the ECU.

If you are worried about the ground to your amp, run a better ground to your amp.

Grounding the head... what's the point? Are the spark plug coils grounded to the head? (they might be, I honestly don't know)

Grounding the chassis in two different locations a foot or so apart with 8 guage... A single 0 guage wire will offer less resistance and more current capacity than two 8 guage any day of the week. Not only is the wire less resistive, but you don't get the resistance from the multiple connections..

This is 100% true, although running wires all over the place randomly is not the fix for these problems. Having clean connections of the right size in the correct locations is the answer.

 

i think it actually looks like crap but my opinion

 

EVERY wire and connection poses resistance... there is no zero resistance material on earth (even supercooled superconductors pose some resistance). And down the road, that resistance continues to increase. Dont get me wrong, I agree in the fact that the effects on the vehicle are most likely un-noticeable, and dont feel the need to run that many grounds. But saying it makes no difference or that connections on the car add no resistance goes against all laws of physics. I'm not tyring to sell the idea of the grounding kit, just stating the truth when it comes to facts around it. And yes, grounding is a huge issue. One of the first things a well experienced tech checks when there are electrical anomolies or system issues on a vehicle is the voltage present on the ground.... that is in every manual in there is, and is a VERY important issue. When you have sensors that are reading to .1V resolution, and you have even .05V higher than normal on a ground connection, it can cause issues. Many typical 02 sensors are seeing les than .3v change total... adding an extra .05V is quite a change! And I would say that in my fathers shop, he probably corrects 10 -15 issues a year simply by tracing down and correcting a bad ground. Connections oxidize and corrode. Someone mentioned that if you have sound system issues.. you simply add a better ground to the amp... not so true in all instances. The ground you run from your amp to the frame/chasis completes its path through the ground wire connecting the chasis to the battery. The negative battery terminal is the common ground, so EVERYTHING must have a good path to it. So you can have a 1 Gauge wire with gold terminals running from the amp to the chasis.. and you will still have issues if the ONE chasis ground from the battery is corroded. It is especially true with sound equipment... V = IR... so if you have a small ground loop (causing noise in the amp) any resistance in the circuit raises the voltage of this signal... and the amp ampifies this signal. The same is true on any signal.. including the signals usd by the ECU.

 

block , chassis , coil/coilpack , trans , thats all i've done , normally the head.

 

I understand the theory as you have stated it and agree. But one thing I understand even better is Toyotas. These are relatively new cars and I wouldn't expect corrosion to even factor into this discussion at this point. I think the majority of these cars have no more resistance or degradation than they did when they left the factory and I don't see in OUR APPLICATION where these ground wires would do any good. Mind you, they won't HURT anything and if you have the spare money burning a hole in your pocket, then by all means! But don't kid yourself that this is a PERFORMANCE mod. Each car design is different and there are possibly some designs out there that this could benifit, but a fresh xB ain't one of them.

 

Lets put it this way. For a $20 mod......It is proven to produce better results for your auto than ANY other $20 mod you can do. I bet you paid more and got less

 

Proven? I'd sure like to see your PROOF!

 

Try this link. A guy like you "trying" to disprove it with dyno results. Well, now he is a believer.
http://www.350zforum.com/tech/groundweb/groundweb.aspx