upgraded alternators?

[ptownTSI]

so i think i need a new one, mine is only putting out 13.5v. seems too low, almost all the cars i've had did 13.9-14.4.

and if i'm getting a new one, i might as well upgrade, what are my options. does any do large case GM alternators for these things.

[europeanplates]

There are a ton of companies making aftermarket alts. AMPTECH comes to mind. Most of these will lose you a little engine power. Where are you checking for the 13.5 that does not sound low if checking at the battery.

Tyler

[ptownTSI]

it was a 13.8 today at the battery...weird. seems like everything is running good actually.

[ptownTSI]

what about putting in the 140amp 5 series alternators? they were 140's right? i am not a fan of "high output" alternators. I bought one from some custom alternator company and the idle amperage sucked and then the idle diode went out and it wasnt making any power at idle. cost me $40 to have it fixed, what a waste of time, and i had to buy another new alternator. $700 spent on alternators and the best one was a stock 150amp replacement that came on a special grand cherokee. stock alternators put out alot of amperage at idle compared to "ho" alternators.

[AndrewBird]

It's not just voltage that matters. What matters is amperage. As long as it is putting out over 12V, I don't see a problem with it.

[KenC]

Stinger

[808BMW]

My 220A Iraggi alt works fine, getting about 14.1 at idle with no load.

[ptownTSI]

my 240 amp "iraggi" alternator for my jeep was the biggest piece of shit ever. that is the alternator i was talking about in my post. didnt know people on here knew about iraggi alt's.

[StereoInstaller1]

OK, so understand here what an alternators job is...

Simply put, an alternator needs to make enough power to overcome the internal resistance of the battery, PLUS the running load placed on it.

Do this: measure your battery voltage AT THE BATTERY. Next, start the car, check for voltage again. Then, turn on every electrical device you have that has a steady load...NOT the stereo or blinkers, but wipers, heater, A/C, rear window defog, whatever....then test again (this is called a "load test")

You will see the difference that the load makes.

Now, with the engine off, go check the voltage at the output of the alternator itself, then check the battery voltage again...you may have a bunch of loss in the wire itself. Oxidization of the wire can cause a 20% drop...and when you only have 13V to start with, 20% is a bunch.

Luke

[808BMW]

my 240 amp "iraggi" alternator for my jeep was the biggest piece of shit ever. that is the alternator i was talking about in my post. didnt know people on here knew about iraggi alt's.

I don't remember exactly which one is which, but when I bought mine, there is a clear explanation that just because it has the most max amps, it doesn't mean it has the highest idle amperage.
I researched and went with (AFAIK in an e30 fitment) the highest idle alt, vs. the highest maximum amperage (which usually performs best at ~3000 rpm or so).

[ptownTSI]

i dont think it had any idle amperage, lol. i was so much happier with my OEM 150 amp.