Not 100 amps but you might want to look at the Man-a-fre website. Problem is I've heard that the Mean Green alternators do not deliver as advertised. I think it's worth looking into however.
From my days (err... forays?) in the car audio world I seem to remember Dominick Iraggi was the guru of all things alternator and could hand wind custom alternators like nobody's business.
He's mostly available on various forums, but I seem to remember if he didn't offer a high output unit you could pull the alternator off your vehicle and he would work it over to a high output unit. Google him and see what you come up with.
What are you needing/wanting/trying to do that the stock alternator isn't enough for?
If it is a surge or short duration demand, maybe a bigger battery would do as well? If it is a shock load (BIG thumpin' amplifier) maybe a capacitor would do it.
What vehicle/engine? (I noted the HDJ81 in your sig line.)
Capacitors don't really do much for a car audio system, especially a high end one. It is a common misconception and an easy way for a company to make more money off people. A second battery is worthless unless you have an alternator capable of charging both while handling the huge draw. Check out Iraggi, good things come from him.
EDIT:: Actually, Iraggi hasn't been doing too good with customer service as of late. try http://www.h-o-alternators.com/
they have one for 80 series, 170 amps I believe
Any review of this company and their product? I am weary of after market "high output" alternators, it is difficult to tell for sure what exactly you are getting.
1. Replacement Alternator HO 170 Amp Alternator Part # 30913
Price includes our 1 year hassle free warranty.
Suggested Retail $735 Your Price $649
Our alternator will directly replace the stock alternator, and interface directly to your car’s computer. No need for brackets or messing with the wire harness. The only change you will make is the output from the alternator to the battery. We recommend 4 gauge or larger.
2. PowrCap We also recommend you add a battery-capacitor to your battery system The PowrCap 400.
Suggested Retail $249 Your Price $199
3. Freight DHL Ground alternator $19
DHL Ground PowrCap $15
DHL Overnight alternator approx. $45
HO alternators are custom built to work with your vehicle’s computer and existing brackets. Please anticipate a one week delivery time due to our current backlog of orders.
h-o-alternators is another reputable alternator company.
Car audio websites are chock full of info about alternators and people who buy and stress them. They separate the good from the bad, and h-o, ohio gen, and a few others make the cut, but most do not.
A cap is not a bad thing, there is this internet rumor that they are and everybody seems to spread it...
A cap is a bad thing if your current draw exceeds your alternator's output capacity, but if it is simply acting as a charge buffer and you are not draining your battery, it can help stabilize voltage. Granted, something like a xstatic batcap is a better choice still, but caps are not inherently a bad product, they are just usually used before other more important issues are addressed.
Well My alternator died recently, and in my HDJ-81 I have 2 batterys(stock), my truck takes a 100amp alternator from the factory to keep all the option for my diesel working. So I am just checking to see if there is any stock replacements in N. America for me, or it is $1250 plus shipping from Japan for a brand new alternator. I think I found a replacement in the Supras, I just have to change the pulley, and they are under $200 online. but I am still looking into it, unfortenatley there is no part # crossovers between N.America and Japan to cross reference my alternator