Best chassis grounding point

[g6civcx]

I'm rewiring my car to a single grounding point on the vehicle's chassis for best electronic performance.

What's your favourite location?

[SexPanda]

grind down a little of the paint on the framerails... Mount it there. Thats what I did with my old s13.

[g6civcx]

grind down a little of the paint on the framerails... Mount it there. Thats what I did with my old s13.

Which part of the frame rail? Any favourite location?

[SexPanda]

Well, when I did it, on my passenger side, right down there next to the motormount (round those parts, somewhere. I did it 2 years ago, never bothered to look at it after that).

It seemed to work pretty good for me. I mean, your frame rail is connected to the entire rest of the chassis, and there isnt too much resistance back to the battery, because of the relatively short distance.

But at the same time, i didn't have gauge lights or brake lights about a year after that. I figure, if it screwed with something, it would have shown up earlier... but idk. I dont claim to be an electrician.

[g6civcx]

I have trunk mounted battery so it will be a long way to go.

The lights and junks like that I don't really care so much. It's my gauges/controllers and ignition that need good grounding.

[SexPanda]

Oh. Well the firewall's decent. Just make sure you sand down the paint first.

[g6civcx]

I don't mind. If the frame rail is the best then I'll just run a long wire to the passenger frame rail where the battery used to be. No biggie.

[SexPanda]

Nah thats too long, you'll have too much resistance. You could mount it somewhere in the trunk area easy. Behind the carpet-wood-whatever panels below your taillights, there's a ton of metal to mount a good ground...

Or your strut tower.

[g6civcx]

The theory is that the heads and block should also mount to the same point.

[SexPanda]

Hmm... Well, meet halfway, and mount it underneath your center consol I suppose...

Thats all metal... But if you have powerwindows/seatbelts, your control unit is under there...

[g6civcx]

Hmm... Well, meet halfway, and mount it underneath your center consol I suppose...

Thats all metal... But if you have powerwindows/seatbelts, your control unit is under there...

Nope. Bare frame. No wiring at all. Nothing.

[Bigsyke]

G6civcx it has been proven that the shock tower bolts provide the best grounding point. For the bat in the trunk, ground on rear shock tower. For engine grounds, find the shortest path you can. Make sure the main engine block ground is the shortest, and the other grounds are same length or longer (prevents ground loops).

[g6civcx]

G6civcx it has been proven that the shock tower bolts provide the best grounding point

Is there any proof for this?

[Bigsyke]

ill have to pull it up. I think tranzex on H-T was talking about a direct link to the suspension is best. Either way the chassis is a central ground, just make sure you dont use copper;

use only non-oxygenated aluminum, with aluminum or gold plated connectors. There was rust burns all over my civic when I used copper crimp 0/1 gauge connectors, even with contact grease.

[racepar1]

The grounding point really doesn't matter, I don't know why you are worried about that. The chasis conducts electricity VERY well, so once the power gets to there it is all gravy. As I recall you are running a carburated small block chevy right? If that is the case grounds are really not an issue since there is really nothing that is computer controlled or monitored there. I would run a 2ga ground cable from each head to the chasis on either side and a 1ga ground from the block to the chasis wherever it is convienient. If you are really worried run another ground from the intake mani, near the distributor, to the firewall. As for the battery ground I use the rear seat belt mounting point for my ground. 1 1ga cable to there and you have a VERY solid grounding set-up.

[g6civcx]

The grounding point really doesn't matter, I don't know why you are worried about that. The chasis conducts electricity VERY well, so once the power gets to there it is all gravy.

I was advised to do so by a very reputable shop. Every vendor I use also advise the same. Whose opinion should I value more, yours or theirs?

As I recall you are running a carburated small block chevy right? If that is the case grounds are really not an issue since there is really nothing that is computer controlled or monitored there.

The only thing I do not have is an ECU. I have other electronics, and probably more so than a typical FI car.

I would run a 2ga ground cable from each head to the chasis on either side and a 1ga ground from the block to the chasis wherever it is convienient. If you are really worried run another ground from the intake mani, near the distributor, to the firewall. As for the battery ground I use the rear seat belt mounting point for my ground. 1 1ga cable to there and you have a VERY solid grounding set-up.

This is what I have now. Electronic issue has been traced to improper ground.


Is there any other assumption you want to address before answering my question, if at all? I don't see the need for this. Just answer the question or don't.

[Fonix36]

i dont know if someone told you already i only read half of the posts but the grounding point should be no further than 11'' away form the battery

[fueled by hate]

Dude buy a meter and test your grounds. Very few people really understand car electronics so I wouldn't swear by a shops opinion. And yes you want your ground cables to be short like fonix36 said.

[racepar1]

I was advised to do so by a very reputable shop. Every vendor I use also advise the same. Whose opinion should I value more, yours or theirs?

Advised to do what? How the hell do you know their "reputable" opinion is any better than mine?

The only thing I do not have is an ECU. I have other electronics, and probably more so than a typical FI car.

The primary purpose for grounding kits is to provide a better ground for the engine'e sensors so they send a more accurate signal to the ecu and respond faster. Since you do not have an ecu uber perfect grounding is not as important. A typical F1 car has multiple computers networked together to monitor and control all the systems, so NO you don't have more electronics than a typical F1 car produced anytime within the last 15-20 years.

This is what I have now. Electronic issue has been traced to improper ground.

What electronic issue? You barely have any electronics! And who told you that it was related to improper ground?

Is there any other assumption you want to address before answering my question, if at all? I don't see the need for this. Just answer the question or don't.

ASSUMPTION!!!??? I made no assumptions! I DID answer your question to the best of my ability with the information you provided! If your ground set-up is as I described then I see no reason for you to have a grounding problem unless there is something wrong with your ground cables. I too have my battery re-located. I run one ground from the block to the frame rail, one from the intake mani to the frame rail, and one from the battery to the rear seatbelt mounting point. I have no ground problems and my car has more electronics in the engine bay than yours does. I really don't get your attitude. I did nothing to instigate anything, kept my post 100% on-topic, and answered your question. WTF is your problem?

[!Zar!]

The grounding point really doesn't matter, I don't know why you are worried about that. The chasis conducts electricity VERY well, so once the power gets to there it is all gravy. As I recall you are running a carburated small block chevy right? If that is the case grounds are really not an issue since there is really nothing that is computer controlled or monitored there. I would run a 2ga ground cable from each head to the chasis on either side and a 1ga ground from the block to the chasis wherever it is convienient. If you are really worried run another ground from the intake mani, near the distributor, to the firewall. As for the battery ground I use the rear seat belt mounting point for my ground. 1 1ga cable to there and you have a VERY solid grounding set-up.

This is the setup that is being run on Falkon240's car for the most part and there are ZERO ground problems.

So I don't see all the hassle that is being produced over this thread.

[S14DB]

The point of having a common ground is so that you don't have to run 2 lines all over the car. As long as your points to the chassis are good you shouldn't have any problems. Running long lines for grounds is asking for loops.

Check your grounding points and use copper washers. If in doubt, steel wool the point clean and then rustolem over after you reinstall.

[didderson]

hopefully you can tell with just this pic. Just make sure you don't ground it in more than 1 different place straight from the battery, you don't want electricity trying to figure out the path of least resistance to your frame all the time, so keep it simple with one nice 0 gauge wire. I screwed mine into an old pass. seatbelt bolt with paint stripped down to metal of course. Get our ur drill and grinding fitting and go to town. And yea, I covered up the other metal with vac. line too because it was touching and making more than 1 ground, and my 'electrician' told me it was a bad idea lol.

http://i116.photobucket.com/albums/o37/didderson/100_3103.jpg