Battery in back question

[lostdaytomorrow 10+ year member]

Well, you should have someone keep the engine at 2k rpm and then retest the voltage at the amp. If the voltage is still dropping, then you need to finish off the big three before calling nathan. But if you finish the big three and you're still dropping to that low of voltage, and the install is correct with 0/1 awg throughout and good ground everywhere, then it sounds like a dud alternator.

 

[cocoleveo7686 10+ year member]

You're only running 1600 watts and a 200 amp alternator can't keep up? Something doesn't add up here. And you also have a g34 up front?
1. Finish the Big 3.

2. Let us know if you have any other accessories that are using current from your alternator (TV's or anything in the car)

3. Find out if your alternator is working correctly and actually giving you 200 amps like it should.

4. I assume you're doing these test with the RPM's at about 2000 right? Getting the peak of the power curve for the alternator. If you're measuring the voltage at idle then that's a problem because the alternator can only put out about 90-100 amps at idle most likely.

5. How long have you had the alternator?

i agree, i have a hifonics bxi2006d with a yellow top up front, 2 out of the 3 big 3 upgrades all i have to do is the positive to alternator, and 0 gauge wiring and my voltage drops to 13.0 when idling and i only have a 110A alternator, if i had a 200A i would think it would sit around 14.4