wtf? 23 amps at 1600 rpm? am I reading that right?

with my car that cruises at 110 km/h @ 2000 rpm, my battery wouldn't be getting enough of a charge and things would fail even before I turned on the stereo

 

He is likely quoting alternator rpm, which is not the same as engine rpm. 1600 alternator rpm is around 500 and change engine rpm. In other words that's about idle speed.

Later,
Brad

 

Alternators are like anything car audio - you get what you pay for.

And pulleys are a big topic on their own.

Yes, you can get bigass alternators that do 200, 300, and 400 amps, at idle, but they are custom alternators for car audio, and priced accordingly. You can get the 200 amp ones locally (to Albertans) by contacting Rob V.O. (Loud Brown Kicker Colt on these boards). Expect to pay at least $2 per amp for anything custom.

You can bolt on bigger alternators onto existing vehicles. Don't expect mind-blowing improvements, and don't expect it to be as easy as changing a light-bulb. Using my van as an example... The stock alternator, a Delco CS130D, does 105 amps. At idle with the stock pulley, it really sucked, music at 40% or better or A/C on and the voltage would drop. So I yanked the stock pulley and went all the way down to the smallest available, a pulley off a late 80's 5.0 Ford (Cougars, Mustangs, etc had these stock) alternator. This improved alternator performance dramatically, at a cost of some engine performance.

But, that little pulley on the stock alternator just wasn't good enough, especially once I doubled up on sub amplifiers. Not feeling rich, but having pretty much any stock style alternator I could want at my disposal, I grabbed the next best thing, a 140 amp Delco CS144 off the shelf.

The CS144 is physically much larger than my stock CS130D, so I had to "squeeze" it in there, but it wasn't to bad. The issue was which pulley to use? There's four common pulley sizes - biggest to smallest being the CS144 stock pulley, then the CS130D stock, then a 9si/10si stock, and then the Ford 5.0 pulley.

I tried the smallest first... It was obviously TOO small, causing excessive labour on my engine. Shift points were screwy, and the alternator sounded like a power plant as I drove around.

So then I tried a stock (the biggest) pulley for a CS144 - and it was to big - Shift points and engine performance were all good again, but alternator performance at idle was crappy.

So next was one size down. Acceptable engine performance, and better alternator performance at idle. But not good enough, A/C on and stereo at 50%ish, and voltage would drop.

So just the other day I stuck on yet one more size smaller, the stock size for a 9si/10si alternator. This is the one I think I'll live with - idle performance is very good, and engine performance is borderline. The shifts seem to hang a little longer, but I can live with it.

So, this was all done for less than $200 retail. A fraction of the cost of anything custom, but at the cost of some time for experimenting. 140 amps is adequate for my van, my sub amps are at 2 ohms, and with all five amps going as loud as I can handle it, they're pulling around 130-150 amps. Where I "use" it most of the time is when my stereo system is drawing 60 to 80 amps.

For competition, my alternator just can't do it. Even if I disable my three full range amps and just run the two sub amps at 1 ohm, they want 210 amps while burping! So I'd need at LEAST a 300 amp alternator for competition.

Being "Battery Bob" has it's advantages though - instead of ponying up for a highpriced custome alternator just for competition use, I throw a locomotive battery cell into my van with a couple 8D CAT's to back it up. 15 volts on tap woohoo! snap that 210 amp load on it and it only drops to 13.8

Holy cow I'm babbling again eh... "Somebody stop me..."

 

if 1600 = 500
what does 8000 = ?

 

because thay say
"This alternator will drop in place of your existing 90-136 amp unit.

This unit will provide 110 amps capability at 800 rpm and 220 amps at 1600-1800 engine rpm.

This alternator has been variable speed load tested for performance!

You can use this high output alternator to power your 2500-watt stereo system. You could install this alternator just as a heavy-duty replacement for the original, this alternator when put on light duty could last a lifetime."

 

320amps hot for $300. A local shop in my area can get ambulance alternators ( it's freakn' huge) and re-wind them. It might not fit in every car but I'm hoping it will fit in a firefly.

 

^ Would you know how much hp it eat up to produce 320 amps?

 

lol the lil firefly wont have anything left

 

fireflys do not have hp or get up and go power