PDA

View Full Version : considering Wire options



XLexusTech
06-12-2013, 06:14 AM
Anyone know the amperage pulled by a stock LS3 starter? I am looking for gauge and material data.. I am considering using thinner wire and also considering Aluminum,

astroracer
06-12-2013, 07:28 AM
Anyone know the amperage pulled by a stock LS3 starter? I am looking for gauge and material data.. I am considering using thinner wire and also considering Aluminum,
Can't help you out on the Amp Draw but I will tell you smaller gauge is not good and mixing that with aluminum will be even worse. Low performance out of the starter and very hot wires is all you will get out of it... If you do anything go bigger with fine strand copper....
Mark

dontlifttoshift
06-12-2013, 09:55 AM
Fuzzy memory but rule of thumb when checking starter draw with a VAT40 was 1/2 the cubic inches. I don't remember why or if that is even correct but it seems close. 350 cid = 175 amps when cranking...approximately.

We use 2 ga welding cable for battery cables, even when mounted in the trunk.

esenior
06-12-2013, 10:45 AM
If you are trying to calculate the smallest size wire needed, then you also need to take into account the wire distance (e.g. if the battery is in the trunk, will need larger wire). I think if you went with a minimum of 2 gauge copper strand, you would be fine. I'm using 2 gauge Quick Car cabling from the trunk to a starter on my 540 Big Block. No problems at all. However, if you are trunk mounted, I would HIGHLY recommend a remote starter relay...you don't want that wire energized all the time.

dontlifttoshift
06-12-2013, 12:11 PM
However, if you are trunk mounted, I would HIGHLY recommend a remote starter relay...you don't want that wire energized all the time.

Why? I have heard this repeated over and over on here and other forums, I think it is just old internet wives tales. You still need a charge back wire to the battery that will be hot all the time, so instead of worrying about 2 wires/cables running from front to back why not just deal with one?

astroracer
06-13-2013, 02:27 AM
Why? I have heard this repeated over and over on here and other forums, I think it is just old internet wives tales. You still need a charge back wire to the battery that will be hot all the time, so instead of worrying about 2 wires/cables running from front to back why not just deal with one?
Old wives tale or not, I choose to have that huge cable dead to the world other then during crank... Why? read this from the MAD Electrical Site:

"The starter motor cable is the only electrical circuit that cannot be protected by a fuse, circuit breaker, Fusible Link, or other short circuit protection. (Because starters can draw all the current that a battery can put out, so the battery cannot put out enough power to “trip” a protective device with high enough capacity for starter motors. All other circuits can be protected, and Fusible Link wires are best for the heavy-duty circuits.)

With our START’M UP system, the cable between the START’M UP solenoid and the starter is electrically “dead,” except for during engine cranking.

It makes good sense to put the START’M UP solenoid next to the battery (in the rear)–to avoid routing a “full-time battery live” cable all the way forward to the starter. (If a “live” starter cable ever became shorted, a fire or battery explosion would be likely.) "

Should be enough reason for anybody to do this the right way.
Mark

Mad's Site:
http://madelectrical.com/catalog/tm-1.shtml

dontlifttoshift
06-13-2013, 04:10 AM
That's all valid. What do the oems do when the battery is in the trunk or under the rear seat?

esenior
06-13-2013, 09:15 AM
Why? I have heard this repeated over and over on here and other forums, I think it is just old internet wives tales. You still need a charge back wire to the battery that will be hot all the time, so instead of worrying about 2 wires/cables running from front to back why not just deal with one?

If you are in an accident and your battery cable is pinched off, that 10-12 gauge charge wire will burn out much faster than your 2 gauge battery cable. Also, you will only need to run a single wire to your starter, although you will have to re-route your starter wire from your ignition switch to the trunk, but since it is only kicking on the relay, it doesn't have to be a very heavy duty wire.

What sold me was that several years ago I did a VERY stupid thing when replacing the accessory belt on my 70 El Camino. I proceeded to loosen the alternator bolts, then I shoved it over to loosen the belt. Since I forgot to unhook the charge wire, the stud grounded out on the head and the charge wire lit up like a christmas tree. The thought of the same thing happening with a 2 gauge cable scared me enough to go with a remote solenoid.