Factory Five Racing Forum banner

1 - 7 of 7 Posts

·
Premium Member
Joined
·
17,764 Posts
Discussion Starter #1
I'm considering adding electric power steering. I'm not positive, but I think EPS uses about 35-40A.

I couldn't use the stock Ford alternator, because it was physically too big to fit in the BDR chassis. So I'm using a smaller 80A racing alternator.

How many amps are needed to run the Coyote engine and 6R80 transmission? I did a Bing search for about 30-40 minutes, and couldn't find the answer.

I'm going to change all my lighting to LED's, so that will reduce power use.
 

·
Premium Member
Joined
·
17,764 Posts
Discussion Starter #2
A hate it when I stump the experts here. :)

I sent an e-mail to E-Power Steering asking the same question. This is the answer I got back today: "Sure, I usually state 70A is the minimum for a street car." So 80A is probably enough.

I'll put this on my list of winter projects.
 

·
Registered
Joined
·
313 Posts
Bob,
With the EPS and a decent radiator fan, 30+ amps, you will be marginal at 80 amps, IMO
I would buy the highest amp alt that will fit.
Just for discussion adding up the max draw will likely be more than 100 amps.
The EPS may not be a continuous load, nor the fan, nor the seat heaters, fuel pump yes, lights, maybe, engine load?
You will be running off the battery and whether the alt can keep the battery charged will be what you will be facing.
I know all this is just basic stuff you already know, but that is what you need to base your answer on. Buy big and best.
 

·
Premium Member
Joined
·
17,764 Posts
Discussion Starter #4
You are correct, in that you have to add it all you for that rare occasion when you are using everything at once. That's why I asked the question. I can look up the specs for everything I might use, which isn't much. But I couldn't find the amp draw for the engine.

The car has a small 80A racing 1 wire alternator. It's the only thing that would fit. I'm going to buy a small clamp on ammeter and see if I can determine what's needed with everything running.
 

·
Charter Member
Joined
·
1,761 Posts
I few years ago I was chasing a short in a Austin Healy kit car. It was blowing a 30 amp fuse in a 20 amp circuit, sometimes.
I bought a used industrial 1-50 amp DC meter online for $50. Made a wood case to hold it and long leads so I could get to the fuse panel or the battery or both.
It turned out to be a bad radio, but now I have a great tool.

I can remove a fuse and plug in the leads from the meter into the fuse holder. I have a couple of AC amp meters but they will not read DC amperes.

A few months ago I bought a 66 Fairlane with the original wiring harness. I use my DC meter to read the total load and each circuit, all six of them. I did replace the fuse block but kept most of the old wiring.
I clipped one lead to the hot post on the battery and the other lead to the battery cable so I can read total load after I turn everything on.
Anyway what I wanted to point out is you may want to find a 100 amp DC meter to use to check total load. I picked the 50 amp meter because it will read one amp on the low end.

A few months ago Coach bought a fan for his Cobra and the instructions was telling him he needed a 80 amp relay. I told him I didn't think that was correct. He called and the tech told him that was correct, he needed a 80 amp relay.
I tested the fan and the "most" it would draw was 11 amps. Coach returned the fan.

I would be interested in what the total load is on the new motors (computers). I know my 06 Mustang would drain a good battery in two weeks if I did not drive it.

A DC amp meter is a great tool on our hot rods.
 

·
Cross Menber
Joined
·
69 Posts
I would be careful about how you wire these meters. This one looks like 100uA (0.000001amp) movement, so it will need a shunt. A shunt is basically a plate that transfers a small percentage of the current to the meter, and passes the rest. This item shows the shunt and how it's used. It is only a 50 amp setup. Also note you must have the polarity correct.
https://www.ebay.com/itm/US-Stock-Analog-Panel-AMP-Current-Ammeter-Meter-Gauge-DH-670-0-50A-DC-Shunt/371816610448?

Another way to measure DC amperage, is a clamp on amp meter. You have to make sure the meter you pick has the ability to read DC amps with the clamp, and how many amps you can measure.
This clone meter shows it will read DC amps via the clamp on, and is a fraction of what a real Fluke meter would cost. A clamp on is also safer with those who are learning about electricity. Just clamp on the wire you want to measure.
https://www.amazon.com/Multimeter-Auto-Ranging-Continuity-Electrical-Capacitance/dp/B01N014USE/
 
1 - 7 of 7 Posts
Top