Bought new 250amp alt but same voltage drop?

[adulbrich 5,000+ posts]

U guys do know that thes ho alts dont put out much more power than a stock alt at idle..they dont start putting out power till 1200-2krpms..at idle u are basically running on battery power ..if ur dropping that low that fast u probably dont have enough batt reserve

My car idles between 1.5k and 2.5k rmp, so it does make a big difference over stock. Idle isn't supposed to be that high though //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[NASTY08IMPALA 5,000+ posts]

My car idles between 1.5k and 2.5k rmp, so it does make a big difference over stock. Idle isn't supposed to be that high though //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

What kinda raggety azz car idles that high lol ..most newer cars idle at 6-900..and these alts dont out out max power from 1200-2k

 

[adulbrich 5,000+ posts]

Its an 86 Fiero. It was made when GM was still kinda working out the kinks with electronic fuel injection, haha. I know they don't put out max power in this range, but it does help when I just want to park and play my system at school.

My truck is a 2007 Silverado, and idles about 500-750

 

[yogegoy]

So you have a run of negative from front battery to back battery and that made your voltage drop less? Right now I have a 320a singer alt and I get voltage drop still too. I'm gonnna put a little smaller belt on it. I have a 20ft run of 1/0 cca on me and a couple terminals... do you think running a run of that from front negative to back negative would help any? Right now I just have my back battery grounded to my chasis.

1/0 neg starting from your alternator main mounting bolts to your negative battery post. Front negative battery post to the negative post of your other batteries and all the original engine, transmission bell housing, cylinder head cover bolts and where ever you can think of.

 

[1-12-t1 10+ year member]

So you have a run of negative from front battery to back battery and that made your voltage drop less? Right now I have a 320a singer alt and I get voltage drop still too. I'm gonnna put a little smaller belt on it. I have a 20ft run of 1/0 cca on me and a couple terminals... do you think running a run of that from front negative to back negative would help any? Right now I just have my back battery grounded to my chasis.

Yes the one run of neg from front battery to back battery bank helped almost a full volt. Now i have my big three done, so in theory, its like my battery bank is connected right to the neg of the alt.

 

[yogegoy]

Just make sure you have a dedicated ground cable from your alternator mounting point to your first battery negative post. It's not necessary connecting all your batteries neg posts to the alternator as long as the first battery has a dedicated cable for the alternator, the rest of the other batteries can be grounded through the solid chassis (seat belt mounting) mounts.

 

[DFW40 10+ year member]

What is the wattage drop from 14.4 to 12.4 with 5K watts roughly?

 

[xoutofmyheadx 10+ year member]

thanks alot for asking this i have the same problem. thought if i just ground fhe 2nd battery to the frame id be ok. but my 1100 watts is killing it at idle. ill work on fixing this and see where i stand