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High Output Alternator Questions

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JJ_Is_Edge

Probationary Member
16
4
Nov 24, 2015
Saugus, Massachusetts
I've done a lot of research on HO alternators in regards to DSMs but the info seems to be from several years ago and sparse.

I believe my alternator is on it's way out (12.8-13 volts with no load and 3,000 rpms, 11.9-12.3 volts with AC, fans, and headlights on at 3,000 rpms)

I have a pretty large stereo system from my old car I haven't gotten around to installing yet, so I figured now would be a pretty good time to install a new higher outputting alternator and the system.

I have been looking at Altstart alternators as there seem to be more info on them, but I'm also looking at Power Basterds and this one https://www.amazon.com/Output-Alternator-1995-1999-Mitsubishi-Eclipse/dp/B00AY1XZVG

I will be running 0gauge wire from the alternator to the battery, and both of my grounds. I will be cleaning EVERY ground point and ensuring everything is tight and secure. I plan on fusing the power wire within 6 inches of the battery, and will also be running a very small .f microfarad capacitor mainly as a distribution block for the amps but also I guess to aid in voltage fluctuations as a byproduct.

My questions are as follows:

1.) What are the most reliable HO alternators (135-160 amps preferable) that are also reasonable priced (I really would like to spend no more than $250-$300 for a 150-160 amp alternator)?

2.) Is it true that all HO alternators have a shorter life than OEM? If so, how long? Months? Years?

3.) Is there a way to bypass the ECU controlling the voltage? Or is that a bad idea?

Thanks in advance!
 
Sorry for the third post here but I thought I'd share something. Before my DSM I had a 3g Eclipse. I had a spare alternator from it and it's rated at 95amps. According to this thread:

http://www.dsmtuners.com/threads/wh...-alternator-8g-galant-and-3g-2-4s-fit.465752/

It should bolt up, however, the bracket is WAY too small. No way it's working. Unless you grind a good inch off the engine block to mount the bottom of it and even then it seems not worth the trouble for 30 amps when the Saturn alternator can be rewound and needs much more minor modification to make work.

I don't have sufficient privelages to post in that thread, so hopefully someone will see this and make a correction there and save someone else the trouble of trying to swap in a 3g alternator to no avail.
 
I have used several high put alternators over the years since 2003 because I too despite the high horsepower my car makes, drive it daily and at the same time love music! I run two 10" rockford fosgate p3s being pushed by a hifonic 2000 watt amp all this alone with 2 fuel pumps, one 450 and 1 255 hp inline not to mention all of the other electronic the car needs to function. I run an ebay 160 amp alternator to this day without issue. The only issue of any alternator is the location somehow I have found its not the amperage of the alternator that determine life span its location. If it is located in the stock position and any oil of any kind gets on it its not going to live long. Usually its the power steering pump leak that kills them the most in the stock location. If you can control the oil leaks your alternator will live a long life span high output or not! just my .02 I must add that the car beat hard which is soothing to me when I am riding on a country back road heading home from the shop!
 
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I agree with keltalon. The alternators on the DSM are poorly positioned, which negatively impacts the life span. In addition to fluids and such leaking onto them, heat kills them just as often. Because of the proximity to the down pipe and exhaust components, the rectifier bridge and other components often cook. If you have removed any of the stock heat shielding, you should replace/reinstall it.

Lastly, if you're running a large stereo, a surge capacitor will help protect the charging system during times where immediate demand is needed. The addition of a 1 farad capacitor will suffice for most stereo systems.

I just installed a 90 amp Bosch in my Galant. I'd highly recommend it: http://www.dsmtuners.com/threads/gstwithpsis-galant-vr4-1837-2000.482807/page-6#post-153588498
 
I run a atuozone 75 amp one and two jl amps about 800 watts with all the other accessories worked for years still works but one amp now .
 
surprised noone has suggested a saturn alt swap, thats on my list of future changes.

the other option past whats been mentioned already, is finding an alternator/starter rebuilding shop (theyre getting rare) and tell them what you want said alternator to do. there was a shop my dad used to take all his heavy equipment and car starters and alts to, and he always had him rewind and modify them for high out put to help with the lights and aux equipment they were running. granted most were diesel alts with less space constraints, but i dont see anything holding a dsm sized alt back from 175-200 amps.

or you could always contact mechman alternators and see if hell make you a custom one.

heat is definitely going to be the biggest enemy of your alt. ive contemplated getting a liquid cooled at from some euro car and seeing about adapting it with a small cooling circuit, but thats alot of extra work, and the cost of those alts is far higher than a saturn or dsm alt.
 
I tried an Ebay one. The bearings were garbage and my volt light would flicker at idle. I emailed the company and would not warranty out the alternator. I sent it back to them and they basically said it was fine. beforehand I took it to 2 different auto places (just the alternator) and both places said it was the bearings. I gave up on this company and just went with a gallant 90 amp. No issues since and its been like 5 years now.

Might want to look into upgrading the big 3 too.

I have used HO alternators from Powermaster in the past in my GMs and have really loved them. I think one of them had like 140 amps at idle and around 200 at cruising speeds. You might try contacting them too.
 
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I had my brand new oem altinator built by a local shop it did 80amps before. And after they worked it it did 130 amps.
 
I agree with Keltalon and GST with PSI
I have a HO alternator and it constantly gives me no lower than 14.2 volts both fans running ALL the time, two Rockford fosgate amps 1k watts,my alternator runs nice and cool in the stock location,due to the undertray I made for the front bumper and my down pipe is coated and wrapped.. Like GST says get a capacitor. I have a 1 farad cap . Car starts out cold at 14.7 volts when warmed 14.4 to 14.6,stereo on 14.2.
 
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