Fuses, Circuit Breakers or nothing at all?

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TAZLDAZL

TAZLDAZL

AMSOIL DEALER
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I am in the process of wiring up my 71 Demon Bracket racer. It is going to be a drag car only. I will be running the following circuits and would like to know what eveyone thinks about uses fuses or CB or nothing at all. I have an electric fuel pump, electric fuel pressure gauge, electric water pump and electric fan, one head light and tail light. I have a tach, electric gauges ie volt & amp along with gauge lights.
Their are products out there that have switch panels already made that are both fused and unfused and some that have breakers. I have been told by some that they don't use anything. Just would like to have some other opinions on this subject.
Thanks
TAZZ
 
Fuses are like any other form of protection, a personal choice until required by law. Here's a point to ponder...
My daughter and I were roaming a pick and pull yard. She noticed that over 50 % of the wrecks suffered fire damage along with the body damage. I explained that this is due to electrical wiring being cut by the sheet metal. All the OEM fuses and carefully engineered harness routing didn't prevent electrical fires in a collision. The OEM wiring is protected from chemicals, chaffing, extreme heat, etc..
With the vibration present in a race car, wire chaffing should be a major concern. along with the heat issues and so on. Bottom line.. You will need to inspect the homemade electrical regularly whether protection is incorporated or not.
 
It would really suck to have a problem like a shorted wire burn a car, melt a bunch of wiring, or burn the alternator/regulator. There is no reason not to use some sort of circuit protection. You should also be using large gage wires for power feeds, relays, etc too.
 
Put SOMETHING in there, and think as you lay everything out: What happens if I crash this thing and "this" wire right here shorts?

You might be trying to crawl out of the thing while it's starting to burn to the ground.

Use oversize wire. I don't remember the name, anymore, but Belden and other companies sell wire with flame resistant insulation, much much better than the thermoplastic crap you see. Fuse/ breaker it as close to the battery as you can get, and keep breakers / fuses away from heat in the engine compartment.
 
I would never ever consider not putting in some sort of protection in anything. I look at it this way, if it has a battery a fire is possible.
 
I just wanted to thank everyone for the replies. I am definatley going to use some sort of fuse set up. Some of the guys that I know that have been racing their whole lives are still old school die hards. If a fuse causes me to loose a race oh well I still have a car to race in and not a burned up piece of junk. Most of the wire I have is all 10-14 Ga. so I should be all right their. I have also used OO Ga. for my battery runs from the trunk to the engine compartment.
Thanks again for everyones support & coments
TAZZ
 
TAZLDAZL said:
I just wanted to thank everyone for the replies. I am definatley going to use some sort of fuse set up. Some of the guys that I know that have been racing their whole lives are still old school die hards. If a fuse causes me to loose a race oh well I still have a car to race in and not a burned up piece of junk. Most of the wire I have is all 10-14 Ga. so I should be all right their. I have also used OO Ga. for my battery runs from the trunk to the engine compartment.
Thanks again for everyones support & coments
TAZZ
Click to expand...

Yeah, here's the thing I was getting at earlier. In your case, you need sort of a "last ditch" effort to prevent fire

Use wire that is WAYYYY oversized.

Don't worry about protecting the load, just worry about protecting the WIRE. this means, say, that if you have an ignition drawing 10-20A but you use wire sized for double that, with a 40-50A fuse/ breaker, all you are protecting is a wire short

A popular suggestion for trunk mount batteries, is to use a purpose cheap aluminum ground cable --short as possible--which will act like a fuse if the main cable shorts.
 
I used a fused switch panel and at least 12ga wire on everything. 8 and 10 on main circuts like for starting and so forth. Even on the grounds for the gauges.
 
Thanks again for the replies.
I will definately go bigger in the starter & altenator circuits & on all my other circuits just to be safe. My battery is grounded to the frame rail in the trunk and then I also have a 00 piece of cable mounted on the same frame rail in the engine bay to hook to the engine. I will probably have another ground wire go from the back of the motor to the firewall so all my electronics inside will have a place to ground to. I have a fiberglass dash that my gauges will mount to. I'm still desciding about what type of switch panel I want. I will either go with a toggle setup on my dash or use the one that I think it's a TCI shifter console with switches on both sides. Since I cut out my fenderwells I will be mounting most of my electronics (MSD, Fuses) inside.
Again thanks for everyones input.
TAZZ
 
I also use welding cable, not normal cable forthe battery cables.. It's has finer and more numerous count of individual wires. Current only travels along the surface of a wire so the more surface area you have, (meaning more strands) the more current it can handle and the less resistance it has.
 
moper said:
Current only travels along the surface of a wire.
Click to expand...

THIS IS NOT TRUE in DC circuits, only in AC circuits. It's called "skin effect" and has less effect at low frequencies (60 hz) than it does at RF (radio frequencies)
 
I once had a car audio fuse between the alt and starter relay. When I painted my engine bay it look out of sort so I did away with it. As of the moment I have 4ga wire from the alt to the starter relay so I think I need to do something to have protection. I have done the amp gauge bypass. Basically this is what I have.

http://madelectrical.com/electricaltech/amp-gauges2.shtml

As you see in the diagram it calls for a 14 ga fusible link between the alt and starter relay. Now in my situation I have 4ga wire............ how do I go from a 4ga wire to a 14ga fusible link? Wouldn't this defeat the purpose of the 4ga wire? I was thinking of a circuit breaker but wasn't sure what amp I need. I run a 75 amp alternator and the battery is located in the trunk.
 
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