Thank you for the link! Lots to learn on that site.

Check these out Mike:

http://www.knipex.com/index.php?id=1216&...&artID=2422

If you search a bit they you can find them much cheaper than list price.

I just need to keep that zip tie tool with the
zip ties.. that way I would use the tool... I tend
to have that tool in my pliers drawer and I just
over look it.. when I was doing road trip cars at
work I had the tool with all my zip ties and used
it all the time.. we would have 100s of zip ties on
each one of those cars... I use to buy the zip ties
for the lab and I would usually buy 5K at a time of
assorted sizes

Where does the bus bar get grounded at...the engine??

Two things.

Rulebook does state holes are legal, but "Visible reinforcement around any hole in any SFI Spec chassis (not just the roll cage) mandatory." Granted, Monte didn't build the chassis and it wasn't up to him to take care of that. And powdercoating is a pain to grind up and touch up after a weld repair, especially the vein stuff.

I believe earth in an automotive system is the negative post on the battery. I've always heard that if powerlines fall on your car, the rubber tires prevent you from being electrocuted as long as you don't step out and touch the ground. Using an isolated ground system like that makes the chassis basically inert as far as the electrical system is concerned. Not having stray current running through the chassis on something with a lot of noise sensitive electronics makes sense to me. Imagine a chassis constructed from a non-conductive material, it would need to have the same design ground system.

I also enjoy doing my electrical systems from scratch rather than any kits and have specific ways of doing things. I have no problem incorporating others' good ideas and techniques. None of mine have been on anything as complex as an EFI, traction-controlled, boosted car though. Still, there's a right way of doing things even on something stupid simple.

Buy the cheapo white ones for initially assembling the harness. Better quality black ones for final assembly. Adds up when your using hundreds of them.

When we were doing the trip cars we would leave
the tie raps just started(dont tighten them).. that
way we could slide more wires in if needed.. the bulk
of the wire we ran were thermocouple wires.. when it
was wired we would organize the bundle them tighten
it up using the zip tie tool and it cuts the tag off..
and believe me the engineers always wants more stuff
added

Don't cut them off till all done ..stick a small screw driver or razor behind the lock bingo pull it back apart ..poor man's way lol

Snap on makes electronic dykes for plastic that cut zip ties easier than anything I've previously used, including guns. They're cut completely smooth with no sharp edges at all. The dykes have a very slight convex cutting edge that gets the exposed tail below the outer edge of the clamp.

All those are UV resistant. The bigger white ones are good for 120 lbs. The smaller ones a good for 18 lbs. I have a EVO 7 those things are the cats azz, you can set the lbs you want and it cuts the ties at that setting and no sharp edges to cut yourself.

Very nice, clean work, but I think something needs to be said about the definition of "floating grounds", just for some clarification. The implication is that ALL grounds go back to the buss bar ( or one point ) with one wire and don't use the cars frame ( or anything other than a wire ) in any way to do it. In your pic, I only see 5 wires ( excluding the 2 large wires on ether end of the bar ). This leads me to believe you are only running 5 separate circuits in the car, each with a separate ground wire? There are some electronic components that require grounding that don't use ground wires, but ground through another component ( engine / chassis ). These components may have a ground wire that goes directly to the floating ground, but the items they are grounding do not. Another example would be your fuel cell. NHRA requires a ground wire on your fuel cell. Would you run a ground wire from your fuel cell all the way to your floating ground buss bar - especially when it ( and items like oil, water senders generate virtually zero RFI?
A floating ground system is a very good idea when dealing with electronic components that generate high levels of RFI or that are very sensitive to the same, but I would be surprised if the frame in most race cars doesn't end up with a path to ground somewhere. Again, very nice work.

I'm confused, are you trying to say there are two types of grounds?

I ran my fuel cell ground strap right to the battery. Since they are both in the trunk. Is this wrong? I just figured ground was ground.

That`s fine and how I did mine but my battery`s are grounded to the back bumper bolts...........

Yes, there are different types of grounds.
Here is a good post I found at:

http://electronics.stackexchange.com/questions/157022/different-types-of-grounding

"They are all connections to the same place, a point of (theoretical) zero voltage but with different purposes:

Signal Ground

This is a reference point from which that signal is measured, due to the inevitable voltage drops when current flows within a circuit, some 'ground' points will be slightly different to others. There may be several signal grounds in a circuit. Imagine if you had an amplifier with a voltage gain of 100 and you were amplifying a tiny signal, if the ground for the signal was elevated by just 0.01V the output would be wrong by 1V. Typically a signal ground would be a connection to the same stage of the circuit as the signal was connected.

Chassis ground

This is the box or frame in which a circuit is built. Typically, it is ground to make a barrier between the user and the circuits inside to prevent electric shock or to shield against interference pick up or radiation. In some high current applications, it is used as a conductor to carry current, for example in a vehicle where running many thick wires to the battery would be impractical but making connection to the chassis is easy almost anywhere. Chassis ground should be connected to the other grounds, usually it is done at a point close to where the power source arrives.

Earth ground

This is a theoretical zero. It is the potential of perfectly conducting Earth beneath your feet but obviously it varies widely depending on where you are. The connection to Earth is normally along your power providers cables or by a rod driven into the ground or sometimes both. It is supposed to be a return path for current in the event of a short circuit on your AC power lines but it is also used in radio applications as a 'zero' reference to read antenna signals against."


For most of the older non-computer controlled cars, the grounding is not much of an issue, but the computer controlled cars have high impedance inputs that can sense very small changes in voltage, and are more sensitive to noise and ground loop problems.

A ground loop is where "in theory" connections to ground are suppose to be the same, but in reality there is some (although small) resistance between the ground connections. All wire has some resistance, the smaller diameter ans longer the length, the higher the resistance the wire has. So one ground may be at a different voltage than the other. The voltage difference is V=IxR so, increases in current (I) make the voltage (V) difference worse when the resistance (R) remains the same.

For example, measure the voltage from the negative battery terminal to the engine block. This would both be considered "ground", but when cranking the engine (high current draw) you will see a small voltage generated from the resistance of the negative battery cable and connections. If you see a large voltage, the battery cable or connections are bad.

My Buss bar is isolated from the car and the negative battery cable goes directly to it.

Very informative, thanks 451Mopar.

I use larger conductors and put buss bars near the loads. They'll be one for the engine and electronics, one under the dash, and one out back. Been doing it that way since the 90s when I was taught that by a friend who wired 6-7 cars a year on the side.

I don't know what it is about the wiring in a car, but i really struggle getting my head around. I think I just haven't grasped the concept. I can read an electrical drawing no problem, but working out how to run the cabling and how things are earthed and powered, I just get lost! I'll get it one day I'm sure!

I always liked the look of the nylon laced open bundle harness.

Link to a "how to lace cable harness" from 1962:

http://www.dairiki.org/hammond/cable-lacing-howto/

very good article. on and off over the years, i have been looking for something like this. thank you for posting !