Here you can see the Powermaster D1000 16-volt battery mounted in the S&W Chassis on Andy's dragster. It was actually about 1" shorter and 8 pounds lighter than our last 16-volt battery we used. Overall the 16-volt battery allows us to save the weight of an alternator, the brackets and possible the weight of a second 12-volt battery a lot of guys have to run. That saves us between 50 and 95 pounds. I'll take a tenth; how about you?
3. Batteries. The battery is the lifeblood of all automotive electrical systems. It is my opinion that you should get the absolute best battery you can find. Cost should not be a factor; finding the right one for you is what matters. I see racers who are trying to start their car for a final round and the battery is dead. They have a $10,000 engine, $700 torque converter, $10,000 enclosed trailer and a lot of money tied-up in entry fees and travel costs. Then I notice they have a $49.95 Wal-Mart battery in the back of their car, along with the cheapest battery cable connectors made, and they are surprised it let them down. There are some awesome batteries in the marketplace today. You can get terrific batteries that come in all sorts of shapes, sizes and power levels. Just look around, do your research on the Internet and ask other racers what they are using (a good tip is to ask the guys who are in the late rounds week after week). I will be doing an in-depth battery / starter article next month, so stay tuned for that. Just to let you know, we chose Powermaster D1000 16-volt batteries for our dragsters. We will not need an alternator; related wiring and one battery will serve us well.
 This is a view of what I have to say is the best thing I have seen for race car wiring. The K&R Wiring kit has relays where you need it, all wires are labeled and fuses are easy to get to. Man, is this different than doing it "from scratch" like I did on the Project 4-Link dragster. |
Battery Chargers: This will be part of my next tech story, but do yourself a favor. If you see a 15-amp battery charger for $49 and another one with micro-processor controls and a 15-amp rating for $89; get the $89 one, it will do a much better job for you when you need it most.
4. What size wire to use. There are as many opinions on this as there are racers reading this article. Our rule of thumb is 1/0 gauge for positive and negative battery cables. We try to use relays for all accessories that use more than 10 amps; such as electric fuel pumps, High-Output water pumps, large fans, etc. With relays we use at least 12-gauge wires to power the relay and 16-gauge to the accessory. With relays the switch wires can be 18-gauge as they carry almost no amperage, they just signal the relay.
Transbrake solenoids are their own little thing. We have seen them wired with 10-gauge, 14-gauge and even 20-gauge. So what is correct? We use 14-gauge as a minimum. Make sure you use a quality connector, like a Weather-tite or similar. Loose connections at the transbrake can cause erratic reaction times and I don't know about you but I have enough problems without adding in a wiring-caused issue with my reaction times!
5. Ground it, ground it, and ground it! Did I mention that one of the single most overlooked problems in race car wiring is ground wires? Actually, it is the lack of a location to make a good ground wire connection. Most of you are probably thinking that your ground wires are plenty good. Ask yourself a few questions and maybe you will see some room for improvement: Where does your battery ground cable attach, the engine block or to the chassis? Where are the ground wires from your water pump, fuel pump, ignition or delay box fastened? Where does your transbrake solenoid ground wire hook up?
If your answers for these questions are the chassis (frame rail), metal floor panel or engine block then you might have a problem.
We recommend running your battery ground cable to the engine block to create the least resistance for the starter circuit and also running a common ground cable to a place in the car where you can hook the rest of your ground wires. This will provide the best performance for your electrical items and reduce chances of a problem from improper grounding.
We also suggest you run the delay box and ignition ground wires directly to the negative post of the battery and not to where you have other items grounded.
Race car wiring is a simple science really. Take care in making the connections, realize that if you feed an accessory with 15 amps and a 12-gauge wire you need to ground it with the same gauge wire and to a good ground connection.
One way to look at this is to look at your starter circuit. Let's say you bought a 1000 amp battery, run big cables to the solenoid, bought the best starter you could and you are hoping it is grounded. If you have aluminum motor plates, powder-coated chassis or urethane engine mounts your engine is basically insulated not grounded. Run a 1/0 cable from the block to the negative post of the battery, as this assures that you will get the best amperage to your starter. This will be a lot more important in later rounds when the starter is hot and your battery is being abused trying to keep everything cool.
Good luck, and I hope you are lucky enough to be racing this time of the year!