HOSS

iTrader: (12)

I have had the March u/d pulley on since April now, I have noticed that recently my battery gauge has been staying below 13. It looks like it is reading around 9-10 after I drive for a while. When I start the car up after it has set for a while, it reads around 14-15, then drops after a bit. I have a sub and amp, electric cutout, walbro 255 fuel pump, wideband a/f setup, and 2 gauges. My questions are:


Should I get the alternator overdrive pulley, thus pretty much cancel out the underdrive crank pulley purpose?

Get a stronger battery, like the optima, and see how that goes?

Or just leave it?

Thanks
Ben

JoeyAnderson

iTrader: (20)

Ben,

Before I'd go with the larger alternator pulley, I'd go with an Optima Battery. I'm running a 25% underdriven Powerbond on my car (with an Optima redtop) without any charging issues at all (stock alternator pulley).

Alternatively, you may want to have a local AutoZone or the like test your alternator -this could be a sign that your alternator is on it's way out.

Good luck!

-Joey

Ferocity02

iTrader: (60)

I'm having similar issues. With the motor off, the windows BARELY roll down and up. I've charged the battery too, same issues. My gauges reset everytime I start the car. But when I start the car, the windows go super fast. So maybe Optima batteries are crap after all.

Dal1as

Get the alternator tested. Is it stock? Hell I have an ASP underdrive pulley and an aftermarket alternator with a "smaller" pulley and don't have charging issues with all accessories running. Alternator starts charging at 650 rpms (higher with the underdrive) though. I also bumped up my idle a bit.

Car_Guy

iTrader: (3)

"Smaller" pulley would make the alternator spin faster thus producing more amps. Maybe that's what he needs to do.

Dal1as

Only problem with that is most aftermarket alternators need to see an 800 rpm idle and with and underdive crank you would need to set your idle around 900 like I did. Also the alternator would need to be setup for an underdrive pulley. It would fry a stock alternator in his case.

I went through all of this for awhile until finding the right amplifier.

I would get the alternator checked. Sounds like the voltage regulatoris going. Then check with Nate and www.excessiveamperage.com and ask him to make you a 200 amp alternator with the lower rpm turn on. That's the one I use now and it works great. It's around $275 I believe.

jmilz28

iTrader: (13)

Get the Optima anyway, excellent mod and insurance against a needless tow.

HavATampa

iTrader: (49)

Same exact problem here and just replaced my failing battery with a red Optima. Still have the exact same problem. Voltage gauge starts out high and slowly drops below 10 on the gauge after driving a little while. Getting the alternator checked next and might pop for one of those high output jewels soon.

Ed Blown Vert

iTrader: (2)

I am having same exact problem. But I already replaced my Yellow Top with a brand new one. Replaced the alternator and installed a smaller pulley on the alternator.

:dunno:

WILWAXU

iTrader: (6)

What's your idle at? A couple hundred more in rpm idle will have the altenator charging all the time.

Dal1as

Yep, I bumped my idle up but then again I have an aftermarket alternator with a much smaller pulley.