Which one to run to the front of the car..

[Vanilla]

Got a ?? for Sparky or anyone for that matter....


I am wiring up the new controler I got and need a question answered...


Where is the best place to put relays for electrical devices (fuel pumps, water pumps, fans, etc). Close to the device, in the car, or does it matter? I want to clean up the engine bay and would rather run one wire from the device to the relay instead of runing 2 wires per device (power wire and switch wire)...



Thanks for the help....



Vanilla

[Sparky]

In the back of the car, I usually put the Fuel Pump Relay near the Fuel Pump.
For the Fan and Water Pump, I usually put the relays inside the car. This has worked for me without any issues.

I hope this helps,
Sparky

[Vanilla]

Fuel pump is in the front of the car. Would it really matter where it goes?


Going to get as much as I can wired tomorrow so I can pull the motor out and change the oil pan and intake gaskets... Want to get all the wiring done before I do that..



Vanilla.

[Sparky]

I have in the past placed the Fuel Pump Relay inside the vehicle along with the Water Pump and Fan Relay, when the Fuel Pump is mounted up front.

A word of advice: Be sure to supply the Fuel Pump with adequate size Wire and Ground. When you consider that the Fuel Pump is probably the 2nd largest current draw on an Electrical System, it only makes good sense to put forth the effort to supply the Pump with adequate size wire. I would recommend a 12 Gauge wire on both the Power and Ground side and please, don’t use the chassis as ground.

I hope this helps,
Sparky

[blownstang]

sorry to bud in here why is it sutch a bad thing to do the chassis ground i had a local guy do some wiring on my car and thats what he did just wondering what i have to change and why all ny stuff is grounded to the chassis.

thanks for any input

[Sparky]

There is too much inconsistency in using the Chassis as a Ground path.

[blownstang]

sorry to bud in here why is it sutch a bad thing to do the chassis ground i had a local guy do some wiring on my car and thats what he did just wondering what i have to change and why all ny stuff is grounded to the chassis.

thanks for any input

[Six_Shooter]

There is too much inconsistency in using the Chassis as a Ground path.


Say what?

I agree that chassis may be difficult for amatures to understand how to use the chassis for ground, but when a proper point is used, the chassis ground is superior to running an independant ground conductor. Due to sheer size it's a rather large conductor. Yes the metal may not be copper, but works very well, even with the metalic properties it has, especially when you realize that the conductivity different between steels and copper is not much. I don't have the chart handy, but I do remember that the difference between steel and copper was not enough to warrant running ground wires to everything. Even using silver, would not warrant that much of an extremity.

I have SOLVED many problems by switched from a ground wire that a customer has ran front to back, for a device to a chassis ground, that was tied in close to the component, using proper techniques, even so far as using star washers, in areas that may have a moisture issue, though I try and ground to areas where that won't happen.

[blownstang]

so what is a good way or were can i run all my grounds to?

thanks for all the help and sorry for the 2 post mistake

[Sparky]

Six Shooter,
Welcome to wiring 101, please take a seat.
Seems like all you want to do is argue my post. Let me ask you, who’s the professional here?
Ya know that’s great in some cases you have fixed some things, but just like your arguments in the Welding post. You have welded on a couple of exhaust systems a couple of times and supposedly gotten away without harm to any electronics. I highly disagree that this has been the case, but whatever.

I strongly disagree with your comment about if you use proper chassis ground that it is superior to running an independent ground conductor, not only do I disagree but I have Data that proves otherwise. An opinion without data is just an opinion, an opinion with data supporting it, is fact!
I do have all the facts, I know what the resistance loss in a 1 foot piece of 1 5/8, 0.083 Chrome moly tube is, which is what makes up most all roll cages. Can you even tell me what the Carbon content is in Chrome Moly? Then I will ask you, how well does a Rotor in a distributor cap fire the Plugs when there is carbon build up on that Rotor?
I have spent the time and money to research a proper grounding method and I’m not going to give it away. I will not spill it here.
Let’s just say I have proven on many occasions that using the chassis as ground in a Racecar is just about the absolute wrong thing to do PERIOD!!
I have spent a fair amount of time with some very intelligent people proving out proper grounding methods. Trust me, if you think that the chassis of a racecar is sufficient for Ground, you have no business wiring a racecar to begin with. Have you ever considered what a Racecar does when it leaves the line or what it does all the way down the Racetrack? It moves, it flexes and if you’re using the chassis as a ground, guess what you’re doing to that ground? You’re changing its resistance! So how is the Racecar supposed to be consistent if the ground is always changing?

Sparky

[LTLHOMER]

Should I run a ground from my coilpack ground all the way back to the battery? What you posted makes sense and it would especially be important for ignition related components.

[Six_Shooter]

Six Shooter,
Welcome to wiring 101, please take a seat.
Seems like all you want to do is argue my post. Let me ask you, who’s the professional here?
Ya know that’s great in some cases you have fixed some things, but just like your arguments in the Welding post. You have welded on a couple of exhaust systems a couple of times and supposedly gotten away without harm to any electronics. I highly disagree that this has been the case, but whatever.

I strongly disagree with your comment about if you use proper chassis ground that it is superior to running an independent ground conductor, not only do I disagree but I have Data that proves otherwise. An opinion without data is just an opinion, an opinion with data supporting it, is fact!
I do have all the facts, I know what the resistance loss in a 1 foot piece of 1 5/8, 0.083 Chrome moly tube is, which is what makes up most all roll cages. Can you even tell me what the Carbon content is in Chrome Moly? Then I will ask you, how well does a Rotor in a distributor cap fire the Plugs when there is carbon build up on that Rotor?
I have spent the time and money to research a proper grounding method and I’m not going to give it away. I will not spill it here.
Let’s just say I have proven on many occasions that using the chassis as ground in a Racecar is just about the absolute wrong thing to do PERIOD!!
I have spent a fair amount of time with some very intelligent people proving out proper grounding methods. Trust me, if you think that the chassis of a racecar is sufficient for Ground, you have no business wiring a racecar to begin with. Have you ever considered what a Racecar does when it leaves the line or what it does all the way down the Racetrack? It moves, it flexes and if you’re using the chassis as a ground, guess what you’re doing to that ground? You’re changing its resistance! So how is the Racecar supposed to be consistent if the ground is always changing?

Sparky

If you're not going to explain why it's supperior then why post? I've been wiring cars most of my life, read many many tech articles on electrical theory, and use that knowledge. True most of my experiance goes in to car audio and security, but I also deal with large currents and some small ones in that arena.

You are the ONLY person I have ever heard say that running a ground wire to each compoenet is better than a chassis ground, except for in a 'Vette. (or other 'glass bodied vehicle ;)) :lol:

Please, show me this data that contradicts everything I have ever read, seen or used in practice.

Please show me how running longer conductors is more reliable than using the chassis as ground, even through all of it's twisting, by that thinking, no electrical should work in a vehicle especially how you lay out your wires, (BTW looks very clean and I like that, more than I can say for a lot of other people, I like the way you tie the wires together and lay them out.), since they are directly tied to the chassis then the resistance should change (assuming it will go up) and cause problems, and don't say copper doesn't have this property, as it is a metal and if one metal has a tendeancy to change resistance as it flexes then so does another.

Great how you throw out the "profesional card", I too as mentioned deal with electrical everyday, I get paid for it, that also makes me a profesional, by definition of the term and the fact that I have learned what I can about electrical.


I'm not hear just to argue, but will question techniques and ideas that contradict what I know about well anything, just happens that you see what I post in this forum.

So I turn the thread back over to you to back up this data, that you are so well protecting.

[Monty Mikho]

"99% of electrical problems can be traced back to the ground". I'm not sure if that statement is 100% true but Im sure it is up there in %'s. If this is the leading cause of problems why not safeguard against it? I have always run a central ground point from the rear of the car (battery ground) to my electronics. Why you ask? It's a 100% safeguard that there is a ground there. Just because it's steel.. doesn't mean a full ground exists!! Any poor ground translates to poor operation of the component!! Let me ask this.. How do you check to make sure your chassis grounds are 100% grounded? And how do you guarantee they will stay grounded over time?

[Sparky]

You want data?
Look at what Petty and Lynch have been running lately. How many times prior to me rewiring the car in late September did they break records and go into the 6’s? I think maybe a handful or so.
Now, how well has that car ran since it left my shop? The first event they ran was Huntsville Mid October, set a record, (after NMRA Bowling Green Kentucky). Then they ran Orlando, (Won), then English Town (A string of 6.80’s there), then Commerce Georgia (a string of 4.40’s there). Oh yeah then there was a string of 6.80’s and a 6.79, not sure which venue. If you watch the car or if you talk to either Steve or Tim, the car shows up runs the number and then continues to run that number all weekend. Don Walsh Jr. is probably another great example as well.

I don’t have to come in here and spill all of what I know, or what I have paid out, or learned through trial and error. To prove that what I do and they way I do it works. I let all my examples speak for it. What you’re asking for is like asking Billy Glidden for a Clutch tune up or a Nitrous tune up. Even as close to Billy as I am, I can’t even get this information out of him. So I don't even ask.
Again, people come in here and ask me for my advice and for the most part they are very appreciative that I take time out of my day to help. I feel that’s what I’m here for, to help. I don’t see anywhere else on the net where the electrical system of a racecar is supported as well as this site.
I posted in my earlier post that I wouldn’t post my grounding methods, that I will in fact safe guard them. I have never said that you should run a ground wire to each component, what I did say was not to use the Chassis as ground. I do supply a ground point, but it isn’t the chassis.
Where would Sonny Leonard and Gene Fulton be if they spilled all their secrets? Where would Shannon Jenkins be with Speed Tech if he let all his secrets out? Everyone with a specialty has secrets of the trade, like them I am not going to throw all my cards on the table. Furthermore, there is a lot more then just my grounding methods that are kept “tight lipped”.
I can tell you this much, I have looked at a lot of racecars with electrical problems and I usually don’t have to look to deep for the problems to start jumping out at me. Whether or not the person I am working with decides to listen to me or not is there choice, they have nothing to loose and everything to gain, but I have sure brought out some serious Pro Stock consistency with some sound ground advice.

It’s good to see that people like yourself pay attention and challenge what I post. It keeps me on my toes...:)

Sparky

[Rick_R]

You want data?
Look at what Petty and Lynch have been running lately. How many times prior to me rewiring the car in late September did they break records and go into the 6’s? I think maybe a handful or so.
Now, how well has that car ran since it left my shop?......snip.... snip...
Sparky
I won't get into an argument over gronnds with you as I feel they are very important, so important I run "Ground Buss" which everthing is grounded to and is attached to the battery and to all major components and the chassis in several places. I even put in faraday ground sheilds but then again I run "plastic" cars.
Now don't get me wrong, this is not meant as a slam, I know grounds are very important, even More important in EFI cars. In EFI cars you are not only dealing with the electrical ground you are aslo dealing with "digital signal" grounds which are much more finiky than electrical. for digital stuff I prefer to use a high strand count cable for all wiring and try to sheild it from RFI. signal timing can be altered by less than perfect return paths (grounds). if the siganls are not perect to the computor you get bad results, garbage in + garbage out. SO I agree with you on the ground issue, I just don't necessarily agree with your use of the example of Lynch's car, That is unless Lynch was having electrical gremlins which were solved by running new grounds, and if that is the case i agree with that to, but you should of stated that you solved his gremlins by fixing his grounds instead of stating "he's faster now". again, this is not meant to be confrontational, I know you do good work. "aamco mike" picked up after you wired his car too, but a lot changed in that time, I'm sure you are resonsible for a least some of it.
again I'm not tring to piss you off, there is a smile on my face, I'm not yelling, just tying to point out some stuff. The guy (or at least I) was hopeing for some physical explanation like "'each weld joint in moly typically adds .004 ohms to the ground path and can cause digital signal refelections'" (the stuff in triple quotes is fiction I just pulled out of my ass as an example), not anacdotal evidence like '"i added STP to my crankcase and picked up 12 seconds in the quarter'" (made up that fiction too:tonqe:). now i realise you are not going to give up all that you have spent your time and money to discover, but a nudge in the right direction would help prove your point to the non-believers, this guy is just like monty asking chris and ray to prove god exists, I now its hard to prove either to a non believer, but a tid bit of info can go along way in getting them on the right path. I think it easier to prove a good ground path is important than god exists by the way, I just don't have the proof of either, I hope i haven't pissed you off and you see my point, and not the one on top of my head:-D

[RRRAAAYYY2]

Oh where to start on this one. First after being the protege for 25+ years of a man that spends most of his time teaching auto electricians after they have become "professionals", I hope my opinion has merit without 400 pages of proofs.

First Sparky has given you a very big hint on just one of the problems with using the chassis as a ground. The fact that the chassis shifts, twists, and does other weird things is not good for your connecting points.

My biggest beef with them is age. As metals age, their metallurgy changes, so what was once seemed like a good idea, becomes a major problem down the road. When you are using a electrical path that is constantly exposed to the elements, its resistance will constantly be increasing. Where as if you are using a sealed negative path (properly size buss bar or wire) the elements have no effect on the path. Without oxygen in the system, the metal used cannot change (age) as rapidly.

Then there is the issue of heat. With no insultating factor in the chassis, it heats up faster than an insultated (shielded) path. The heat causes more resistance.

Rick brought up EFI, RFI and such. If you are not using a high strand & cross stranded cable or braided cable, you get lots of dirty DC in your system. The cleaner your current/voltage, the better and more consistant electronic devices will work. Hence Sparky's proof is in the pudding. His customers are at the top of their fields. We cannot credit all of that to Sparky, but I can say with everything being run on electronics, he is a huge part of their success.

In my electric vehicles I use a completely isolated positive and negative paths. This way if crap happens, just touching the positive cable or battery terminal to the frame won't kill someone. Unfortunately you cannot do this with an ICE car, because of the ignition.

How important is the ground? First you need to start looking at your electrical system, as what it truly is, a system. We usually use reference to water pipes. If on your positive side you have a six inch pipe, but on the negative side a 1" pipe, how well is the system going to work? Everything needs to be equal, and the saying a chain is only as strong as the weakest link really applies to electrical as well.

One thing you can never do is use OEM manufacturers as examples. They are in the market of mass production, so cost is their biggest concern. They also work to different standards than what you guys should be.

Six Shooter, maybe this example will help shed some light on this. In a stereo system, why don't you use the chassis as a ground for your amps to your speakers? The same applies for the rest of the system.

If you guys want to check your systems for performance, you can do a voltage drop test. Here is a link:
http://www.svapowerproducts.com/html/voltage_drop.html

I also have a tech section (getting dated now) that many mechanics found interesting:
http://www.svapowerproducts.com/html/tech_tips.html

The voltage drop testing is super easy to do, a child under 10 is capable. The only thing it does not help with is dirty/noisy current. The tech section might help in the fact if you get used to what has gone wrong in the past, you can apply that to new problems of today.

There is my two cents. Actually a lot more than 2 cents as it took me an hour type this one finger at a time. My shop rate is more than 2 cents an hour so.... Hence the reason why it is sometimes nice just to be able to say do it this way.

[Sparky]

The example of Lynch’s car is a perfect example. When that car came through the door, everybody was chasing it, although it wasn’t as consistent as it is now, electrically, it broke every rule out there. There are some simple rules to follow as you plan out and wire a car, for example, you mentioned Digital and Analog Grounds, the EFI system has both of these and all of the EFI manufactures want these grounds on the Battery, These were tied to the side of the Cage. Components were lying on top of one another. This is a no, no. There were high current wires running along with low voltage, low current wires, so cross talk may have been a factor. These were just a few of the problems that plagued the car electrically. But I bring the Ground issue up in this case because more times then not it is the most neglected part of an electrical system. I get cases like this in here all the time. It’s not uncommon here to remove and replace the electrical system and put emphasis on the important parts of the electrical system that need it. When the car is returned to the customer, it’s a completely different animal. A once fat tune up is now lean, the cars reaction time changes, every tune up change made to the car responds, the customer now has a car that he can work with. In saying that doesn’t mean I was the sole reason the car started going fast. But what I am saying is the key ingredient that was holding the program back was the inefficient electrical system, now the car goes out and breaks records, runs consistent and wins races, because all the key ingredients are working together efficiently.
An electrical system can be a difficult nut to crack, especially if it’s done improperly. I see this all the time, a great big power wire and a tiny ground wire. How efficient is this going to work. This example is hard on everything, the power, the ground and the component. Ray mentions that everything has to be equal and that’s a very, very valid point. Another classic example of poor grounding is the ground methods used on a Nitrous system to the intake manifold, I love this one. Aluminum is by far the worst conductor of electricity of all the metals, but I see people bolt the ground to the intake or a carburetor stud and off they go but not before the put a 70 AMP relay or a continuous duty solenoid to drive the power side. If you would have provided an adequate clean ground path, I don’t think you would need that big relay or solenoid.
Let’s look at this for a bit, we bolt a Nitrous ground to the intake for ground, The Engine is Aluminum and is bolted to Engine plates which are Aluminum and then is bolted to a Powder Coated and/or Painted Chassis. How efficient is this ground method going to be compared to one that was run off the Negative side of the battery?
I may not spell out what to do with the Ground side of a car, but if you read between the lines, I’m pretty sure you get a good idea of what I am doing.
:)

Just for the record, I am not mad or pissed off or even irritated. It would take a lot more then that to do the above, unless that’s what you guys are trying to do (LOL)

Sparky

[Six_Shooter]

I'm going to look through the rest of what you posted and Ray, you know I do agree with a lot of what you say, but this one just has me absolutly baffled......
Especially when Sparky is the ONLY person that says this, everything else that I have read, seen, experimented with shows me that running a seperate ground wire causes other problems.
I don't remember the theory behind it right now, but there was also something to do with (and this is not a technical description, since I usually don't get into these discussions, it's also early :lol: ), but equalizing or there's another word that I'm looking for, the ground potential of each component through the chassis also the magnetic/RFI feild that is created or supported by the chassis.

Six Shooter, maybe this example will help shed some light on this. In a stereo system, why don't you use the chassis as a ground for your amps to your speakers? The same applies for the rest of the system.

Because in most cases the amp would fry outputs, due to a few factors. The audio signal is AC, and so is the signal between the amplifier and the speakers. (yes I know you can run have an AC signal on a DC system) The amp is designed in such a way that isolation between the chassis (of the amp) ground and the signal needs to be maintained, because in many cases the output of the amp would also cause problems with the power supply in the amp, due to the sometimes very high voltage that can be on the outputs of the amp. So no, the same does not apply, since there seems to be differening reasons.


But overall this discussion is moot, because there is no information that is supporting the need for running these extra grounds, also no information what is grounded directly and what is not, because that was also mentioned, just a lot on conjecture about well "why do you do it this way?" If you're here to help, help, don't sit here and say "I'm better than the next guy" without adding "Because of........"
I dunno, maybe I'm one of those odd ones that shares my "secrets", because I also learned them from somebody else or learned them with someone else, so I share the knowledge, because I'm not afraid that someone else might come along and steal my thunder, really in the grand scheme of things, I'd rather help people with what I know, then hinder them with what I won't tell them, by dangling a something over thier head just out of reach, saying "na na na, I'm know but I'm not going to tell you".
I have to agree with Rick_R, while you, Sparky, may have helped Petty and others get thier cars down the track, I wouldn't be taking all the credit, like the examples here of a "system", everyone that works or has worked on those cars, has had a hand in getting those cars where they are. Though Rick_R worded it much more elequently. :)

[Six_Shooter]

Looks like we were posting at the same time....

I completly agree with you on the nitrous example, I see it many times too.
I agree that aluminium is a poor conductor, but I haven't mentioned anything about grounding to aluminium.
I also agree that components mounted on other components in a lot cases, can be bad, different example but coild used in passive crossovers in audio systems, the air core coils need to be a 90 degree angle to one another, to avoid the same cross talk you are talking about.

I just don't see enough info being posted about what you consider important to ground to the battery and what is unimportant enough to ground to the chassis, which I can't think of anything that is "less important" than other components.

BTW, for the record I'm not trying to piss anyone off here, like I've already said, if I see something that goes against what I already know, or see in practice, I question it, unfortunatly like the proving god exists scenario, I don't just take someones word for it. ;)

[Rick_R]

Now that you explained what you did to lynch's car and the issues it had, your example makes perfect sense. i just wasn't getting the full drift of what you were trying to say. Maybe part of it is that I understand electric 101 and know how important grounds are and I would never ground to an alumium panel, I even use high strand count static discharge ground straps on engines despite having 2 other grounds on it (one near the starter the other for efi). all 3 of them have star washer and conductive zinc paste at the conections. I also wear a belt and suspenders :). BTW i'm not sure if i believe in god but I do believe in RFI and funky static discharge issues, I've directly experienced those:cool:.

[Sparky]

Six,
I ground everything to the Battery, ok! How I do that, no, I won’t spill sorry.
What better ground do you have in any car then the battery itself? Isn’t that the other side of the loop? Positive to Ground with some sort of resistor in-between?

I'm not claming any credit for Lynch. I used it as an example of bad vs. good and the adverse affects. I don't dangle things over people’s heads. I hand out lots of free good valid info here. Yes there are some things I may not come right out and give the answer to, but I think that I point people in a clear direction. What good is giving out answers if no one learns from it?
If you think about it, you learn form it and you remember it.
I am not afraid of anyone stealing any so called "thunder". I never get any praise for what I do. You want to come see what it is I do, c'mon out, will wire one together.

Maybe I'm the weird one that has fallen off the rocker one too many times. But I feel fortunate to help and get involved with the people that I do, whom ever that may be, big or little names alike. The fact that they call or come here and ask what they should do or what I think, makes me feel good about what I do. That maybe I am making a difference in an area that has been neglected for so long, if nothing else, at least an electrical arena has been created to ask questions and express ideas about an area, which is not understood by everyone. That otherwise didn’t exist a few years ago.
When I first started doing this a lot of people told me that it would never work, well it has gone form a hobby, to a part time business to my full time career. I never argued the point that it wouldn't work with the naysayer’s. I simply let them think what they wanted and kept moving forward. I knew that the electronics were going to get more complicated and that the race world would need good people to support it electrically. Like you, I like to practice what I have learned, what I have been taught and go with what works for me. Sometimes I do read and get hit with things that don’t necessarily make sense. I give it some thought and try to make some sense of it. But sometimes I just find it easier to agree to disagree.

Sparky

[RRRAAAYYY2]

Six Shooter,
You defintely just dated yourself, :) . For years and years OE manufacturers used the chassis to ground speaker systems in cars, and they did not blow their amps. I know you would never do this now a days. Just like when we were kids and and hooked up our home stereo speakers to our cars. The stuff all still worked, just not as good as it could under optimal conditions.

About aluminum. Is it really a the poorest of conducters? Steel is by far the worst, then silver, then copper. Ok, pick yourself back up off the floor, :), and quit laughing. It is true that aluminum has a really high resistant rating. But aluminum is also very, very light compared to those other metals. So if you look at it from a pound to pound perspective, aluminum is one of the best.

I just learned this last year. Here was the example. My new bike will at some point have 3000+ amps at over 48volts passing through the system. So using wires is pretty much out of the question. I will be using flat stock metal connectors. Since I am building this one right the first time, I did not rule out using solid silver, or gold plated silver or copper bar.

But before I forked out $1000+ for the solid silver or gold plating, I thought I should ask some wise men I know. So I posted to the EVList (electric vehicle forum) and asked them. Afterall they have tons of experience with this kind of thing. (experience out weighes education everytime in my books) My biggest concern was the amperage blowing the gold plating off.

Their answer to me was very surprising, they told me to use aluminum. Using rough figures here: Basically I would have to double the size of my conductors if I used aluminum to get the same carrying capactity as the copper. But since aluminum weighes less than half as much as copper, I would save weight. So pound for pound, aluminum is one of the best conductors out there.

Not that this negates Sparky's example of the intake manifold. There are several reasons why not to do this. First there is the heat in the manifold, it gets a lot hotter than a seperate wire coming off. Then there are all the connections, it is not uncommon to see .2 volt drop over mated surfaces, especially a year down the road. The more connections you make, the more places you are asking for trouble.

I am sorry I didn't give you enough back up information. This sometimes can be hard to do. It might mean typing out a thesis for an answer, which is hugely time consuming. A lot of times it could be because I forgot why. And after a long time knowing why or remembering why becomes less important to me. It has advantages for conversations like this, but in the long run I no longer need to know/remember why to do it right. So the why part gets pushed further and further back as I try to stuff new info into my drug abused ever aging mind. :)

The whole reason I mentioned who I learned form, from the age of 11, was that it should have had some merit. I wasn't trying to have a pissing contest, just more to say that I have some pretty reliable sources. We have made a career out of fixing engineers mistakes, and training/educating others in our field. Kind of just was trying to say I am not coming from left field, or a mechanic with a chip on my shoulder.

For Sparky the proof is in his customers cars. The guys that set records are using the best of the best. That is why they are doing so good. To me that is proof enough that Sparky knows what he is doing. It is also proof that their tranny suppliers, their clutch guys, etc., all know what they are doing. Copying what they do won't hurt you. i.e. If I seen Hutch pour a gallon of diesel oil in a tranny, I would too. (Actually in a case like that, I might ask why) Hope you get my point though.

[Six_Shooter]

No Ray, I didn't bring up the old ways of using the chassis ground for speakers, because the last car to do that, with a very low output deck was as well as I can remember early or mid '70s, but probably before that.

In a system not designed to use chassis ground for speaker return path it will damage the amplifiers. Back in the late '80s, early '90s when I was first getting serious about Car Audio, I heard of many people going into shops asking why thier amps were damaged, to find out that they used the chassis as ground, because thier "buddy" told them it was ok to do so. Sure at lower outputs it would probably be ok for a while, but then turn it up and blown outputs, damaged power supplies, even damaged RCA outputs from decks were common when this technique was used. Try using chassis ground with an amp from today (AND BYPASS THE INTERNAL PROTECTION) and the amp will fry. But it has nothing to do with the chassis being a "poor conductor" at that point, it comes from interferance, and crosstalk, moreso the difference in voltages, and types of current. You don't find it so much now, but you'd usually find stickers on these amps, and even decks that said "Not to be used in a chassis ground or common ground speaker system".

If I seen Hutch pour a gallon of diesel oil in a tranny, I would too. (Actually in a case like that, I might ask why) Hope you get my point though.

Like you, I am here doing the same, asking why? If I am given good enough reasons why, then I will re-wire my system and do so from now on.

I think Sparky was just being a jackass*, but everything is grounded to the battery. :P
But this does bring up a good question:
In this theoretical question, the Vehicle has an engine mounted alternator and a trunk or rear mounted battery(ies).
Since the car runs off the alternator (when the car is running), why use so much emphasis on battery connections? The filtering effect that the battery provides? Or something else?
Let's take the original question regarding where to place the relay for the fuel pump. Again, assuming the alternator is engine mounted. We know the fuel pump is mounted up front, so the shortest path between the source and the device would be to keep the relay up front, and have the wire connected between the charge post and the relay then to the fuel pump. There would be less AC filtering this way, but just as an idea, a capacitor that will also provide filtering, be lighter than a battery, and can keep up with current change demands quicker than a battery, could be placed up front.

Oh and Sparky, I do agree that the electrical side of cars, especially race cars has been neglected for far too long. I'm not here to bust your chops, far from it, but like I have said before and even Ray has mentioned in his post, I'll ask why, I don't just follow blindly, never have, never will, and that goes for a lot of things, not just automotive electrical. ;) So, I will say this, I'm glad you're here to help, it just bugs me to no end when people will say "I have a better way, but I'm not going to tell you." I'm sure you can understand why I get frustrated, especially when in the next sentance you will say you're here to help. Know what I mean?
Again, this is only meant as a friendly convo, not a my dad has bigger balls than your dad, and he can beat up your grandmother with one eye tied behind his elbow elementary school thing.

*Don't take that personally, just friendly ribbing. ;)

[LTLHOMER]

But this does bring up a good question:
In this theoretical question, the Vehicle has an engine mounted alternator and a trunk or rear mounted battery(ies).
Since the car runs off the alternator (when the car is running), why use so much emphasis on battery connections? The filtering effect that the battery provides? Or something else?
Let's take the original question regarding where to place the relay for the fuel pump. Again, assuming the alternator is engine mounted. We know the fuel pump is mounted up front, so the shortest path between the source and the device would be to keep the relay up front, and have the wire connected between the charge post and the relay then to the fuel pump. There would be less AC filtering this way, but just as an idea, a capacitor that will also provide filtering, be lighter than a battery, and can keep up with current change demands quicker than a battery, could be placed up front.


If you wired it the way you are proposing, then your battery kill would not shutoff all the power (engine still running, alternator still turning and feeding say a fuel pump that is pumping fuel into a fire, etc) which is a no-no according to the nhra/ihra safety people. You are required to run the power from the alternator back to the battery side of the cutoff switch so that killing the power really KILLS the power not just power from the battery...

[Bill Glidden]

Although I am a huge fan of Sparky, and everyone knows he is hands on with my cars operation. I feel that everyone who disagrees with him should stick to their opinions, and do what they feel, I would then have that many less to deal with in competition!!!!! This guys records, and cutomers speak for themself, questions are one thing, but complete badgering is silly! Thanks Sparky for all that you have done for me! BG

[Sparky]

All,
Like I said you guys keep me on my toes. I do like to help and try to offer as much as I can. I guess it catches me a bit off guard when you guys tune in to the post and ask why. I'm not used to people listening to me.....
I don’t mean to lead you blindly and I don’t mean to frustrate anyone. I’m just trying to help without giving up the farm. I hope you can understand where I’m coming form as well. I don’t try to take any of this personally, but now that I understand that your only asking why for your own understanding, helps me realize that I’m not being second guessed, which makes a lot of sense. I’m sorry if I offended anyone.

I really want to thank you guys for the posts that are put up here. I think with the type of experience everyone brings to the table, adds value to the site and deems it more credible.
Thank you for stopping in and keeping this section in line. I will try in future post to be more optimistic and not so pessimistic.

Six, I wasn’t really being a jack-ass was I? :) (LOL)

Thanks guys for helping me build this section.

Sparky

[RRRAAAYYY2]

Six Shooter,
You don't need to convince me that doing that with the speakers is a bad idea. I figured that out in the 70's. My point is look at your reasoning. There is your answer to why. Not the whole reason, but a good enough reason on its own.

LTLHOMER,
I have been arguing with tech at IHRA for awhile over where the alternator charge wire goes. Technically by the rules it cannot go to the battery. But you are so right about it having to. I do not know how many rectifier bridges I have replaced over the years because the alternator was on the dead side of the kill switch. As of last year I was told that no one would get in trouble for going directly to the battery, as long as it had no other termination points (but they are not rewriting any rules).
I would go directly to the battery instead of the kill switch itself. Keeps the protective benefits of the battery in the loop fore sure.
I do not normally recommend fusing an alternators output line. But when in a race car, I think it is a good idea, with an over kill size fuse though, i.e. 200amp fuse for a 150amp alternator, mounted close as possible to the battery. This way if things are going badly, the kill swtich kills the car, the fuse blows if the alternator wire is shorted. That only leaves the wire from the battery to kill switch live.

[Six_Shooter]

If you wired it the way you are proposing, then your battery kill would not shutoff all the power (engine still running, alternator still turning and feeding say a fuel pump that is pumping fuel into a fire, etc) which is a no-no according to the nhra/ihra safety people. You are required to run the power from the alternator back to the battery side of the cutoff switch so that killing the power really KILLS the power not just power from the battery...

Ahh, yes, I forgot about the kill switch, in that scenario, but provided that the car would still shut off, by another means then, let's add that in. ;)

I believe that Taylor makes a switch that is four post that will allow the ignition wire or power supply to the ignition switch itself to be run through the kill switch which would then kill the car, and not need to run the alternator charge cable to the battery directly and have potential fire issues if that wire was shorted, and would need to fuse that lead near the battery, like Ray has suggested, which I agree with completly.

Sparky, I understand you not wanting to give away everything, but that's what drives me to ask again, and again and again and again and again and ag.... you get the picture. I need proof, not just "this is better" I need that "because" before I'm convinced. ;)

BTW Ray, I don't see what you're getting at. These components were designed to use a negative ground, well technically it is "0 volts" a "Negative ground" would be less than zero. ;) That's not the point though..... These components in question were designed to use the chassis or battery negative terminal as part of the circuit, the amplifiers output was designed NOT to use this same path. So I'm Comfuzzled.

[LTLHOMER]

Six Shooter,
You don't need to convince me that doing that with the speakers is a bad idea. I figured that out in the 70's. My point is look at your reasoning. There is your answer to why. Not the whole reason, but a good enough reason on its own.

LTLHOMER,
I have been arguing with tech at IHRA for awhile over where the alternator charge wire goes. Technically by the rules it cannot go to the battery. But you are so right about it having to. I do not know how many rectifier bridges I have replaced over the years because the alternator was on the dead side of the kill switch. As of last year I was told that no one would get in trouble for going directly to the battery, as long as it had no other termination points (but they are not rewriting any rules).
I would go directly to the battery instead of the kill switch itself. Keeps the protective benefits of the battery in the loop fore sure.
I do not normally recommend fusing an alternators output line. But when in a race car, I think it is a good idea, with an over kill size fuse though, i.e. 200amp fuse for a 150amp alternator, mounted close as possible to the battery. This way if things are going badly, the kill swtich kills the car, the fuse blows if the alternator wire is shorted. That only leaves the wire from the battery to kill switch live.

So you would recommend running the alternator lead right to the positive post on the battery? And I won't get in any trouble? Sounds like a plan!

[Rick_R]

Sparky,
I hope you don't think I was badgering you, I'm just one of those inquisive/curious guys that want to know "why" not just "how", that way i can apply it to the next problem that is a little different. Sorta like the old give a man a fish he can eat for a day , teach him how to fish....
Think of me as one of those pesky little kids whose every other word is "WHY".
I quess i just have a quest for knowledge, and I prefer to get my Knowledge from those that "do", instead of those that "can't" so teach.

[RRRAAAYYY2]

Six Shooter,
The kill switch is supposed to make ALL the wiring in the vehicle become dead, i.e. to have no potential, not just make the vehicle stop running.

When speaking about Negative and Positive in a DC electrical system, it is not negative zero and plus zero, it is talking about the polarity of the electrons surrounding atoms. Opposites attract. So what happens is you have negative charged electrons on one side of a device (say a starter) and positive on the other side of the device. The switch (think of as a gate) in the starter seperates them. When that switch is opened up, the negative electrons are attracted to the positive electrons so the flow through the device. This cause the device to perform a function. Technically DC current flows from negative to positive.

When designing a component for an automobile, they are NOT designed to work in conjunction with other parts, so to speak. They are designed to work in a stand alone perfect world. They share a common source of power (negative path) only because the OE installer wishes to do it this way. The designer of the device would prefer that his component had its positive, its own negative, and its own fuse. That would just cost way too much to do in the average car.

Take an alternator for instance. An alternator should only ever be run straight to the battery. I know of only a handful of alternators that where ever designed not to do this. This is something you will never see in an OEM application, as it costs money (extra wire) to do this. The extra money, around $2.00 a vehicle, doesn't seem like much, until you consider that they make 2 million cars, then it becomes a big deal. The alternator will work fine not going directly to the battery, but it won't work perfectly.

Did you know that GM is spending on average a $1000 per vehicle for voltage spike suppression and filters. It is like that with most manufacturers. Actually probably even more so as GM and now most Bosch equipped cars use avalanche diodes in their alternators. The diodes suppress any spike over 32volts coming from the alternator, a vehicles biggest source of voltage spikes.

As race cars slowly catch up to the OEM's in the electronics department, you will see race cars needing to address these problems as well.

[LTLHOMER]

I just bought one of these so I can run the alternator right to the battery, and also run the battery to my cutoff switch...and it also has two -8 gauge or smaller inputs for my big stuff 3 connections that are supposed to go right to the battery.

http://www.autotoys.com/x/cust/product.php?productid=2251&cat=0&page=1

Two 0-4 gauge openings and two 8 gauge openings.

Cool piece for only $10 and it's gotta work better than that I'm doing now...

[RRRAAAYYY2]

Looks pretty. The biggest question is what is the base metal. It could be steel, copper, brass, lead. Most likely steel as it has threads in it. So it might not be the best conducter there is in high amp applications. But will probably be fine for a regular race car. Tin plated solid copper connectors are my first choice.

Sparky will give you better advice on the big stuff connections than I can.

I see these types of terminals on a lot of stereo cars that are daily drivers. Big mistake, as the copper in the wire is exposed to air, and the elements. Just the air alone is bad for it, add some moisture and it just starts to corrode. I have been able to just snap 1/0 cable off the connector (because of corrosion) even when the cable is only a year old.

[LTLHOMER]

Looks pretty. The biggest question is what is the base metal. It could be steel, copper, brass, lead. Most likely steel as it has threads in it. So it might not be the best conducter there is in high amp applications. But will probably be fine for a regular race car. Tin plated solid copper connectors are my first choice.

Sparky will give you better advice on the big stuff connections than I can.

I see these types of terminals on a lot of stereo cars that are daily drivers. Big mistake, as the copper in the wire is exposed to air, and the elements. Just the air alone is bad for it, add some moisture and it just starts to corrode. I have been able to just snap 1/0 cable off the connector (because of corrosion) even when the cable is only a year old.

Doh! Oh well we'll see if it's worth the 10 bucks. Gotta be better than the junk I'm using now connected at the wrong places. lol

Is there something I can put on the wire to keep it from corroding? Maybe some kinda dielectric grease so the air can't get to it and that would help in conductivity anyways right?

[RRRAAAYYY2]

The grease itself is a poor conductor, but it is a very good idea. They also make sprays that you can use, but they die everything red. Basicaly you want to keep oxygen away from the bare wire. If you use grease it will squish away from the areas that are making contact. I would put the ends in, clamp them down, and then stuff the grease in the opening with a small screwdriver.
Once you have it installed take a digital multimeter set to read volts. Put one end on the bare wire sticking out of the clamp, the other end on the battery post. Then crank your motor over and read what the multimeter says. It should stay at 0.0something. If it reads more than o.1 then I would fix the connection. Try tightening, cleaning, etc. If you can't get it below 0.0 then I would toss the clamp and start again.

[LTLHOMER]

The grease itself is a poor conductor, but it is a very good idea. They also make sprays that you can use, but they die everything red. Basicaly you want to keep oxygen away from the bare wire. If you use grease it will squish away from the areas that are making contact. I would put the ends in, clamp them down, and then stuff the grease in the opening with a small screwdriver.
Once you have it installed take a digital multimeter set to read volts. Put one end on the bare wire sticking out of the clamp, the other end on the battery post. Then crank your motor over and read what the multimeter says. It should stay at 0.0something. If it reads more than o.1 then I would fix the connection. Try tightening, cleaning, etc. If you can't get it below 0.0 then I would toss the clamp and start again.

Allright thanks Ray I'll let you know how it goes when the thing arrives...