Shmee

iTrader: (3)

I'm curious if anyone is running a high current alternator in their LS, I replaced my stock on with a cheap BA alternator while I have my OEM unit rebuilt (ps leak damaged) and noticed right away the 80amp BA alternator struggles to keep up as well as the stock alt.

With the plans to put in a new stereo as well as air, I'm concerned that the charging system will not be able to keep up with the demand of a cycling pair of compressors and a stereo, not to mention the rest of the car, all at once.

I found a few places selling high output alternators which lead me back to these guys: http://store.mechmanhighoutputaltern...400/93-00/4-0/

Anyone have some experience and wisdom in this area with the LS?
At triple and quadruple the output of stock, are there any problems I could have with such a high output alternator such as these?

HiloDB1

iTrader: (3)

Mechman makes good alternators and are pretty well regarded in the car audio scene. Other reputable brands would be DC Power and Singer Alternator. Any of them can build you a strong alternator with more than enough output at idle and full RPM for a host of aftermarket goodies.

Shibumi1

i havent seen such a large unit put in an LS... but if you swap to SC34U (optima red top batteries) 1 up front and 1 in the rear you shouldnt need anything other than the oem unit.. (understanding that for every 45mins of nonstop music at high volumes u must lower to low levels for AT LEAST 15-20 MINS to allow the batteries to recharge)if you follow this simple rule you wont have any issues at all...


also make sure to use 100%OFC (OXYGEN FREE COPPER) NOT CCA (COPPER COLORED/CLAD ALUMINUM) THIS GOES FOR YOUR GROUNDS AS WELL..... also increase the oem grounds to at least the same size as your power wire....


as most car audio companies have switched to CCA due to the high cost of copper.. i use high strand count welding cable (had to run some wire in my car today so this price is accurate... $2.75 per ft of pure copper 1awg wire)


good luck

HiloDB1

iTrader: (3)

This is not necessarily true. You do not need to use OFC cable as CCA is fine. As long as you are within the rating of the cable you will be fine.

LScowboyLS

absolutely valid concerns! - you cannot have too high of an alternator output, as long as you increase the wire sizing appropriately to handle the extra current, but you can certainly have too low of current output rated alternator, in fact. on the 95-97 LS400, the lowly 80 amp stock alternator is almost too small for the car as stock! - So with large accessories such as high powered sub amps, high power headlamps, etc. - a high amp alternator is not just a good idea, it is a necessity if you want the alternator to charge adequately and your vehicle and your accessories to run correctly!

when I have been too cheap to buy a new higher amp alternator in situation where the output was close, I would cheat and install a slightly smaller pulley on the alternator for say a ~10% increase in output, in a pinch! - If you go much smaller, you will just prematurely burn out the alternator, so caution on doing this!



this is mostly correct - you definitely want to avoid any aluminum wiring, copper clad or otherwise, all wiring needs to be 100% copper, though it doesn't have to be oxygen free, but it does have to be adequate size (gauge) for the amperage it is carrying

Shmee

iTrader: (3)

What do you define as "high volume?" Are we talking 90-105db or like 130+??

My concern is that with 2 compressors drawing some 27-40amps each, plus a stereo drawing maybe another 20-40amps at a reasonable level, plus the standard electrical load of the normal systems, I'm probably north of double the alternators current output.


My plan was to run a 0/1ga power wire from the battery to the trunk to another battery, then a distro block and then 4ga power wires to 2 amps and the 2 compressors.

I planned to upgrade the big3 but is there a specific ratio for the alternator output:wire gauge?

LScowboyLS

there are standard electrical tables that will tell you the wire gauge and how many amps can be carried on that gauge - it all depends on the distance (and the wire material) - so a cable running 2 feet doesn't have to be as large of a size to handle the same amperage (current) as one running 20 feet

if you did decide to use the copper clad aluminum (not recommended) your cables will need to be considerably larger than with pure copper

Sc0pe

iTrader: (1)

Just run Pure OFC 0/1 AWG (I recommend Knukonceptz Kolossus) and be done with it. That's the route I'm going with so I can be confident my electrical system will handle anything and everything I throw at it.Here's a link to the Mechman alternator mentioned earlier on in this thread. There is a 320A version available but you won't need it unless you ditched your rear seats and turned your car into a seismic generator.

LScowboyLS

here ya go!

Shibumi1

aluminum has a higher internal resistance than copper (and is also prone disintegration over heavy current draw) earlier this yr we built a 2013 mustang with a show quality system.. from day one we noticed random clipping and distortion.. and couldnt seem to find the cause... about a month in, the customer dropped off the car bcuz the clipping became to annoying...

understand we used what we thought was top quality wire.. it turns out a large audio company (who i wont name) switched to cca.... in far less than 30 days the speaker (12awg) running into the doors had literally TURNED TO DUST!!!!!!!! inside the rubber casing.... the same was true about the 1awg wire at the battery terminal under the hood.... so the entire car had to be rewired!!!! of course at no cost to the customer.... think of wire as the arteries that feed energy to the body u want the best flow possible or guess what..HEART ATTACK...(in this case blown amps, blown speakers or worst case a stroke! car burning to the ground!!)

i say OFC as it guarantees that it truly is copper (if ur sure u have real copper then so be it) but it took a week to disassemble the mustang then to rebuild it again... at a huge loss in labor...

if u have time an money to waste then CCA is all yours... we wont use it at all ever again!!!!!

(6 other cars have been back since an there are plenty more on the books)...to save a few bucks.. for cca your car is literally a fire hazard

the wire chart posted above is a great guideline (but that chart is for constant draw.... music is a bit more dynamic so 1awg is about as large as u would need...(under 1000watts REAL POWER USE 8AWG...OVER 1000watts REAL POWER 4AWG UP TO 1800WATTS THEN 2AWG OR 1AWG IS SUGGESTED) if ur aux batts are in the rear it will reduce the draw on the long run from the front.. (a guideline i use is the output of the alternator+ 50% above its max output works well) which is also how i fuse it (within 18" from ea battery)



@ Shmee .. high volume is "usually" anything above half to 3/4 volume(as max volume is never suggest for any length of time).. as ea system is designed differently its hard to say.. but if u notice your lights dimming or your amps are getting hot its usually a good time to turn it down... remember most alternators put out max output about 2500+ rpm (not at idle) unless its been set up that way.. so if your parking lot pimpin...it will take a bit longer to recharge..

Shmee

iTrader: (3)

Thanks, that's great info.
So if I'm looking at a stereo with ~1000-1200W rms draw(subs at 500-600w and 4 speakers at 100-150w rms each) then 4awg is needed but because I plan to run a couple compressors off the same power supply then I do noose to run 1/0 from the battery to the trunk.

And from the alternator to the battery, would I still need 1/0, along with the main ground. Anything more?

LScowboyLS

I would run 1/0 anywhere it will fit, wire that is too big is fine, wire that is too small can cause a car fire!

Sc0pe

iTrader: (1)

Pretty much what Cowboy said. Just make sure all your grounds match the power wires. Inadequate ground wires are just as bad as running inadequate power. Furthermore, the general consensus for a solid ground is scraping the paint (you can use a flathead screwdriver, or get a steel wool attachment for a drill - please do this, but keep a vacuum on hand because the paint dust will get EVERYWHERE), drilling and adding a bolt. With my car, we used a star washer and two self-tapping screws (one to put around the ring terminal and another to hold it in place). I'll add a picture on here in case you want an idea on where I ran my ground.

When it comes time to do the air, I'm reusing the 4 AWG from my current audio setup and rerunning it to a distro block to get it down to 8 AWG and use the two runs to each compressor, as well as running one line back up to the front to yet another distro block to get it down to ~16 AWG so I have more than enough power to run any small accessories (i.e. LEDs, USB connections, power wire for air gauges, etc.).

stebster

NOT TRUE... CANT EVEN PLAY 3 MINUTES AT HALF VOLUME AFTER 25 MIN BREAK. DO THE UPGRADE. I HAD 2x10 's almost every brand. 2x12 MTX now 2x15 L7 SQUARE 2017 model. THE ALTERNATOR for
POWER IS REQUIRED + EXTRA BATTERY