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Re: Grounding for battery in the trunck? [Re: Dean_Kuzluzski] #1722051
01/07/15 11:41 PM
01/07/15 11:41 PM
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Trumussia
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jcc Offline
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"copper being best"

Not busting your chops, but Audi uses pure silver for wiring on its Kerv racing cars, being slightly better then copper for the task.


If you can't dazzle them with diamonds, don't waste your time, because nothing will
Re: Grounding for battery in the trunck? [Re: Monte_Smith] #1722052
01/08/15 12:48 AM
01/08/15 12:48 AM
Joined: Nov 2003
Posts: 1,969
Chandler, AZ
Duner Offline
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Quote:

Wire a few EFI cars.....chase your ass for weeks with EMI "noise" and get back to me on if its "worth" it

Monte




Hahaha.... I've been chasing my tail trying to get rid of noise on my TPS signal forever.... and I haven't even moved my battery yet. Who knows, bigger cable and better grounds might just fix it yet!

Re: Grounding for battery in the trunck? [Re: Monte_Smith] #1722053
01/08/15 12:58 AM
01/08/15 12:58 AM
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Az
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Quote:

Quote:

Quote:

A ground is NOT a ground so to speak. Lot to be said for "clean" grounds and "noisy" grounds. Something like a starter, doesn't NEED a clean ground.......ANYTHING electronic DOES. You want to use the chassis as one big ground conductor, that's fine, many do, but it is NOT the best way to do it. I prefer to do it right and prevent any future issues. Seen too many problems too many times that drove guys crazy, that was fixed with a proper ground system.

I used to ground stuff like everybody else, to the chassis, until I learned better. Just because it is the way you have ALWAYS done something doesn't mean its the BEST way. You would like to think you do something long enough, that you find BETTER ways to do it........not the same old same oh.

Monte


I agreed with your post - in principal, but you gotta look at the bigger picture some times. For instance, is the added weight of having to run a ground cable from a rear mounted battery to the front of the car off set by the better conductivity of the cable over the frame? Doubt if you could measure the difference. The reason that it is still done the way it was done 30 years ago is because nothing "practically" better has come along. Change for the sake of change is not better. Who ever coined the phrase "change is good" must be in sales. Who ever invented "scotch-locks" should be shot. Minimum wiring, minimum ( and clean ) connections, still the best bet IMO.


Wire a few EFI cars.....chase your ass for weeks with EMI "noise" and get back to me on if its "worth" it

Monte


Ok


Fastest 300
Re: Grounding for battery in the trunck? [Re: jcc] #1722054
01/08/15 01:28 AM
01/08/15 01:28 AM
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Bend,OR USA
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Quote:

"copper being best"

Not busting your chops, but Audi uses pure silver for wiring on its Kerv racing cars, being slightly better then copper for the task.


Silver is NOT the best conductor of electricity, gold is I think copper is number four and I can't remember if silver is number two or three I believe aluminum is number 7 or lower. Tin and silver plated copper holds up well to corrosion, but gold is the hot setup for the least resistance, best against corrosion and the best conducting


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Grounding for battery in the trunck? [Re: jcc] #1722055
01/08/15 01:41 AM
01/08/15 01:41 AM
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Posts: 27,421
Balt. Md
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383man Offline
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Quote:

I am not sure I agree, I would rather have one reliable, properly sized, tested/measured ground, then, unless in an in an emergency, a random selection of undersized, maybe good grounds, and let the electrical devices figure which one is best. IE, if a ground is thought to be not correct, then any additional backup grounds have to all be the same proper size, thinking you can "share" or combine grounds is unwise and asking for future problems.

"static straps", are primarily for grounding static charges, not grounds.





My point was not to have a bunch of undersize grounds. My point was its nothing wrong with adding a ground of the correct size even if you already have a ground of the correct size in whatever circuit you are working with. Hence the saying .....you can never have to many grounds. Ron

Re: Grounding for battery in the trunck? [Re: Cab_Burge] #1722056
01/08/15 02:13 AM
01/08/15 02:13 AM
Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
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Quote:

The most electrically conductive element is silver, followed by copper and gold. Silver also has the highest thermal conductivity of any element and the highest light reflectance. Although it is the best conductor, copper and gold are used more often in electrical applications because copper is less expensive and gold has a much higher corrosion resistance.




http://chemistry.about.com/od/elements/f/What-Is-The-Most-Conductive-Element.htm


I run my cars much like Monty suggest. I ground the frame and run a dedicated ground circuit for sensitive electronic/ignition.

One thing to watch for on cars is ground looping. It may create static and noise.

Re: Grounding for battery in the trunck? [Re: RobX4406] #1722057
01/08/15 03:28 AM
01/08/15 03:28 AM
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Posts: 5,540
Hot Rod Ridge
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Re: Grounding for battery in the trunck? [Re: FastmOp] #1722058
01/08/15 09:30 AM
01/08/15 09:30 AM
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MI, usa
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I run a twisted pair with shielding and a shielding ground wire from the MSD box to both the coil and the crank trigger. However the box is grounded to the cage like everything else.
Doug

Re: Grounding for battery in the trunck? [Re: dvw] #1722059
01/08/15 02:14 PM
01/08/15 02:14 PM
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Quote:

No one has answered how production cars with numerous electronic devices rely on the "terrible" floor pan/unibody to attach ALL the grounds in the entire vehicle. This remains the same regardless of where the battery is located. There is a heck a lot of surface area in a unibody. I do agree if the car is a rust bucket the unibody spot welds could possibly be an issue. If its so bad that the majority of the spot welds are suspect there is a way bigger issue than the ground path. When my car was completed I voltage drop tested my ground side under load. There was .2 volts drop at 28 amp draw from the center ground post of the battery to the ground wire of the dual cooling fans. The battery is grounded to a 3/8" stud welded to the cage with 1awg cable. The block/trans is also grounded with 1awg cable Doug


I think you are missing the point on race cars, it's not a voltage drop issue. it is a noise issue and old analog ignitions may never have a problem. but with new digital race ignitions it is an issue.

Re: Grounding for battery in the trunck? [Re: Quicktree] #1722060
01/08/15 02:28 PM
01/08/15 02:28 PM
Joined: Jun 2003
Posts: 52,968
Romeo MI
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Quote:

Quote:

No one has answered how production cars with numerous electronic devices rely on the "terrible" floor pan/unibody to attach ALL the grounds in the entire vehicle. This remains the same regardless of where the battery is located. There is a heck a lot of surface area in a unibody. I do agree if the car is a rust bucket the unibody spot welds could possibly be an issue. If its so bad that the majority of the spot welds are suspect there is a way bigger issue than the ground path. When my car was completed I voltage drop tested my ground side under load. There was .2 volts drop at 28 amp draw from the center ground post of the battery to the ground wire of the dual cooling fans. The battery is grounded to a 3/8" stud welded to the cage with 1awg cable. The block/trans is also grounded with 1awg cable Doug


I think you are missing the point on race cars, it's not a voltage drop issue. it is a noise issue and old analog ignitions may never have a problem. but with new digital race ignitions it is an issue.




There are on board computers on all the new cars..
multiple ones in some cases... they are really touchy
with noise

Re: Grounding for battery in the trunck? [Re: MR_P_BODY] #1722061
01/08/15 02:33 PM
01/08/15 02:33 PM
Joined: Jan 2003
Posts: 32,394
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Quicktree Offline
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Quote:

Quote:

Quote:

No one has answered how production cars with numerous electronic devices rely on the "terrible" floor pan/unibody to attach ALL the grounds in the entire vehicle. This remains the same regardless of where the battery is located. There is a heck a lot of surface area in a unibody. I do agree if the car is a rust bucket the unibody spot welds could possibly be an issue. If its so bad that the majority of the spot welds are suspect there is a way bigger issue than the ground path. When my car was completed I voltage drop tested my ground side under load. There was .2 volts drop at 28 amp draw from the center ground post of the battery to the ground wire of the dual cooling fans. The battery is grounded to a 3/8" stud welded to the cage with 1awg cable. The block/trans is also grounded with 1awg cable Doug


I think you are missing the point on race cars, it's not a voltage drop issue. it is a noise issue and old analog ignitions may never have a problem. but with new digital race ignitions it is an issue.




There are on board computers on all the new cars..
multiple ones in some cases... they are really touchy
with noise



i bet they are not anywhere as sensitive as race ignitions. and how many different filters are they using? how confined are they?

Re: Grounding for battery in the trunck? [Re: 383man] #1722062
01/08/15 02:38 PM
01/08/15 02:38 PM
Joined: Dec 2003
Posts: 21,959
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jcc Offline
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Quote:

Quote:

I am not sure I agree, I would rather have one reliable, properly sized, tested/measured ground, then, unless in an in an emergency, a random selection of undersized, maybe good grounds, and let the electrical devices figure which one is best. IE, if a ground is thought to be not correct, then any additional backup grounds have to all be the same proper size, thinking you can "share" or combine grounds is unwise and asking for future problems.

"static straps", are primarily for grounding static charges, not grounds.





My point was not to have a bunch of undersize grounds. My point was its nothing wrong with adding a ground of the correct size even if you already have a ground of the correct size in whatever circuit you are working with. Hence the saying .....you can never have to many grounds. Ron




I believe I understand your overall point, but the problem I see is when one has multiple grounds, often for extra assurance/back-up/whatever, unless they are all sized for the largest possible current demand, when one of the redundant grounds becomes less effective (corrosion, intermittent, loose, disconnected in error, etc), the current will then seek another ground with less resistance, and IF that ground is undersize, issues arise. Therefore My concept is just to have a single "great" ground path, and if a problem with that ground arises, the effect is immediate and maybe very obvious, and likely in a single location. That's why having a "lot" of grounds is not a goal for me.


If you can't dazzle them with diamonds, don't waste your time, because nothing will
Re: Grounding for battery in the trunck? [Re: Quicktree] #1722063
01/08/15 02:41 PM
01/08/15 02:41 PM
Joined: Jun 2003
Posts: 52,968
Romeo MI
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bet they are not anywhere as sensitive as race ignitions. and how many different filters are they using? how confined are they?




I dont know about the filters but its the low voltage
stuff that your trying to protect.. your dealing
with 0-5 volts or even 0-2 volts and the auto companies
run the grounds as said above... are they keeping it
clean with filters or not.. I dont know... I know
I had to deal with millivolt stuff on the fuel tank
(mainly the filler tube when it was plastic)

Re: Grounding for battery in the trunck? [Re: MR_P_BODY] #1722064
01/08/15 02:45 PM
01/08/15 02:45 PM
Joined: Jan 2003
Posts: 32,394
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Quote:

bet they are not anywhere as sensitive as race ignitions. and how many different filters are they using? how confined are they?




I dont know about the filters but its the low voltage
stuff that your trying to protect.. your dealing
with 0-5 volts or even 0-2 volts and the auto companies
run the grounds as said above... are they keeping it
clean with filters or not.. I dont know... I know
I had to deal with millivolt stuff on the fuel tank
(mainly the filler tube when it was plastic)



there you have it, that why you can't compare a pass vehicle with a race car.

Re: Grounding for battery in the trunck? [Re: Quicktree] #1722065
01/08/15 04:01 PM
01/08/15 04:01 PM
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North Alabama
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North Alabama
Noise can be a problem on any EFI car, but you add noise to the incredible cylinder pressure that you have in some of these cars that make 3000+ HP and you have a SERIOUS issue.

This is a typical thing we see, especially on THIS site. Guys have always done things a certain way, it works OK and when something different is suggested, they attempt to shoot that theory full of holes. Just because you have always done something a certain way, does not make it the right way for EVERY car out there.

I changed the way I wired cars, because I DID have issues on some high HP EFI cars with intermittent noise. So common sense tells you that if the changes were BETTER for EFI cars, they were better in general. At least that's how I looked at it, plus to me the "floating ground" deal is clean and easy. So what you have to string a couple extra wires. It makes trouble shooting SO much easier, because things are contained in a specific area.

As far as factory cars........who cares......I don't, because we are not talking about factory cars. Plus, when I worked for Dodge, I know our ECUs were directly battery grounded. Are they still??.........don't know, don't care.

So, you want to ground your whole car through the chassis or sheetmetal...........fine, no problem, but no need to try and prove it's the ONLY way or best way to do it

Oh yeah, forgot something and this is FACT not here say. The Holley Dominator ECU is capable of running factory LS coils. Millions of cars out there with LS coils. However, in a HIGH hp application, with high cylinder pressures, the "flyback" voltage from the LS coild was horrendous. Bad enough in fact, that we had to put a stupid amount of filtering in our boxes to keep the junky coils from smoking our boxes. So the point......what the factory cars have don't mean squat in a race car

Monte

Re: Grounding for battery in the trunck? [Re: Monte_Smith] #1722066
01/08/15 04:19 PM
01/08/15 04:19 PM
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Frostbitefalls MN (Rocky&Bullw...
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Monte, thanks for making those points. It occurred to me that if I don't want to run a huge ground all the way to the battery in the trunk, then I should at least ground the critical components on their own circuit all the way to the battery with a properly sized ground wire for the load, and totally isolated from the starter.


8.77 153 mph best, 3055 lbs 528 indy 440-1 alky
Re: Grounding for battery in the trunck? [Re: RobX4406] #1722067
01/08/15 04:25 PM
01/08/15 04:25 PM
Joined: Aug 2003
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Bend,OR USA
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Quote:

Quote:

The most electrically conductive element is silver, followed by copper and gold. Silver also has the highest thermal conductivity of any element and the highest light reflectance. Although it is the best conductor, copper and gold are used more often in electrical applications because copper is less expensive and gold has a much higher corrosion resistance.




http://chemistry.about.com/od/elements/f/What-Is-The-Most-Conductive-Element.htm

.



I wonder where this Professor got or decided to make this statemnet, I was taught in the 1970s/1980 in basic elctricity and electronic college classes that gold was best for conductivity and silver and copper where down the ladder 3 or 4 from gold I wonder what changed
Not trying to hijack, clarification sometimes helps, sometimes hinders
My main message is the path of electron flow from the battery is out the negative side of the battery so that side, path, is really important to get right


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Grounding for battery in the trunck? [Re: Monte_Smith] #1722068
01/08/15 04:33 PM
01/08/15 04:33 PM
Joined: Jul 2004
Posts: 19,301
State of confusion
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Just had a thought.............What if I ran a smaller gauge wire directly from my trunk mounted batts along the frame w/the fuel line for example BUT like factory cars, had it attached along the frame say every 2' or so............


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Re: Grounding for battery in the trunck? [Re: Thumperdart] #1722069
01/08/15 04:53 PM
01/08/15 04:53 PM
Joined: Jun 2003
Posts: 52,968
Romeo MI
MR_P_BODY Offline
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Quote:

Just had a thought.............What if I ran a smaller gauge wire directly from my trunk mounted batts along the frame w/the fuel line for example BUT like factory cars, had it attached along the frame say every 2' or so............




Monte is talking about ISOLATED ground.. totally separate
from the main ground... the ONLY place that they are
common is at the battery itself... the battery acts
as a filter and takes spikes and what not out of it

Re: Grounding for battery in the trunck? [Re: Cab_Burge] #1722070
01/08/15 05:15 PM
01/08/15 05:15 PM
Joined: Apr 2005
Posts: 12,271
Overpriced Housing Central
RobX4406 Offline
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Quote:

Quote:

Quote:

The most electrically conductive element is silver, followed by copper and gold. Silver also has the highest thermal conductivity of any element and the highest light reflectance. Although it is the best conductor, copper and gold are used more often in electrical applications because copper is less expensive and gold has a much higher corrosion resistance.




http://chemistry.about.com/od/elements/f/What-Is-The-Most-Conductive-Element.htm

.



I wonder where this Professor got or decided to make this statemnet, I was taught in the 1970s/1980 in basic elctricity and electronic college classes that gold was best for conductivity and silver and copper where down the ladder 3 or 4 from gold I wonder what changed
Not trying to hijack, clarification sometimes helps, sometimes hinders
My main message is the path of electron flow from the battery is out the negative side of the battery so that side, path, is really important to get right




Another from a manufacturer
http://www.tibtech.com/conductivity.php

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