HOZZMANRX7

iTrader: (43)

Yes, and there is a shop in Pomona off 2nd ave that will do it.

BUT, because you're essentially shoving a square peg in a round hole, low RPM (read at idle) volts will suck unless you have a very small replacement pulley to compensate.

meximan

iTrader: (37)

oh wow thats close by, But why the need to downsize the pulley? Its a factory unit right, so shouldnt the factory pulley be ok?

meximan

iTrader: (37)

Ahh just found a post on another thread by you hozz! that answered my question bout the smaller pulley size vs higher alt rpms.

The whole reason im looking at this upgrade is in teh event i run the taurus efan on my s4 TII.

I was considering the FD alt upgrade, but with 25 ish amps just in the taurus e-fan, that doesnt leave much "upgrade" room as far as amps are concerned..

jackhild59

iTrader: (7)

You didn't read all 8 (now 9) pages.

meximan

iTrader: (37)

mmmm yup i did ! and then some

^ read one post up

jackhild59

iTrader: (7)

Then you have either sort term memory loss or reading comprehension issues. Your question was completely discussed early in the thread.

ITSWILL

iTrader: (12)

Any reason in particular you needed to insult him?...

jackhild59

iTrader: (7)

I did it just so you would ask!
If you wanted to accuse me of being tactless you might be right.

Seriously, since when did stating obvious facts become an insult? Would you prefer I said 'Search Noob!!!' I gave a fairly benign hint. Then I stated facts. The rewind/upgrade alternator was COMPLETELY thrashed out in this thread. 25% of the first 8 pages are full of the discussion of rewind alternators. It's impossible to miss if you actually read the thread.

There are only three possibilities:
meximan read the thread and he didn't understand the discussion
Or he forgot what he read.
Or he didn't really read the thread and wanted someone to spoon feed him.

If meximan had questions about what he read or didn't completely understand what he read he could ask questions about the details in the thread, instead of asking a question that was *completely* thrashed out in the thread.


Hey meximan-I'm sorry if I hurt your feelings!



ITSWILL: I am sure meximan feels all better since you protected him from my bluntness.

RotaryEvolution

iTrader: (30)

and sometimes i will get it that it's shorter to just explain than it is to insult not just one person but another passeryby as well.

unless i'm just pissed at the world for some reason, then i call everyone the **** out!

meximan

iTrader: (37)

Lol...Nah ill explain myself...

I spent the last 2 days researching E-fans, benifits, disadvantages, taurus bs blackmagic vs mark VIII vs Fiero....which then branched out to.....

How to wire said E-fan, to toggle switch, to **** toggle switch and using thermosensors and reading threads upon threads of this...

which led to, Taurus fan Sucking s4 Alts dry (amperage wise)..

which in turn lead to this thread as well as others....I read through 8 pages of this thread.

Perhaps i missed the part about rewinded alts, I do remember reading an old member out of washingtons thread about his mathmatical decision to stay away from the rewinded alt, and it spinning at 24,000 rpm at 8k rpm's....Did i understand what he meant at the time no....Hence why at the end of this thread when i saw "justjeff" using his rewinded alt pushing 130 amps or whatever it was,

I felt that i just spent 8 pages of thread that could have been answered with a simple question...After the hozzmans post, I researched some more and found out what he meant on one of the other threads he had posted on

I do my homework! MY brain is proboblyl fried right now from staring at a screen but im not one of the lazy people that want answers spoon fed to them, I want to ask a specific question and get a specific answer. I learned everything i know about rotorys from the 5 years i been on this forum by helpfull members that know/have already been through it.

MY feelings arent hurt lol, but as simply as the "blunt" response was made, the answer could have been typed in the same amount of time/words.

But as you can see, right after my post i made i found my answer thanks to some usefull feedback and i had posted i found my answer

Thanks dudes!

RotaryEvolution

iTrader: (30)

the 92-94 ford tempo alternator puts out 130amps from the factory. one customer got a rewound one from motorcityreman which pushes 170amps for $176 which is part #7751N-Tempo from them.

but no one should ever need 170 amps, 130 is more than most will ever need even with a massive E-fan.

the stator always spins the same speed regardless of rewinding the alternator, so i have no idea why he would put that down as an issue. i have never checked the pulley phasing but if the stock pulleys push 24,000 RPMs then so will the rewound alternator. put a larger diameter pulley on it if you want to underdrive it.

jackhild59

iTrader: (7)

It's pretty simple. Take a 70 amp s4 alternator as an example. You want more amperage. The stator wire gauge is sized for 70 amps max. If the current draw is more than 70 amps, electrical resistance causes the alternator to overheat. Output goes down, not up. Keep this up and eventually you burn out the alternator. So you decide to get it rewound for high output. To rewind and get more amperage, you need larger wire diameter on the stator windings. So you wind with larger wire and everything is good, right? Not quite.

The stator has a physical size limit. The larger wire means you can fit fewer wraps or winds on the stator. You can make more current without overheating but at a given rpm you have fewer wraps breaking the magnetic field. So at a given rpm the rewound alternator makes fewer volts. You might be making plenty of amps, but idle volts on many high amp rewinds are low, often 12 volts or less. The more extreme the rewind capacity the worse the effect. Rewind 70 amp for 90 amps, you probably get close to idle voltage you want. Rewind that 70 amp for 130 or 200 amps, you are not gonna be happy.

What to do? You could set your idle higher, maybe up to 1200-1500 rpm to get your volts up. The recommended solution is nearly always to speed up the alternator with a smaller pulley effectively overdriving the rewound alternator.

But guess what? Now that you are overdriving your new alternator, it makes more heat, the bearings wear faster, the brushes wear faster etc. On an engine that makes 8,000 rpm you easily exceed the alternator rpm that is considered safe.

There are several threads regarding problems with rewound high output rewind alternators. One is on the front page right nowTypical rewind story.

Physical space limitations coupled with electrical theory makes the rewind more of a science project than a solution.

Every reputable rewind company tells you exactly what I just posted. They will specifically tell you that it is normal for a rewind to make low voltage at idle and that the warranty does not cover this situation.

http://www.motorcityreman.com/technical-info.html

Installation

Installing our high amp alternator will be a direct bolt-in installation unless otherwise notified before purchase. Proper performace, though requires more than standard installation expertise.
Keep in mind that you are not installing a stock alternator and it will not function the same on your car as your stock alternator does. The most common problem you may experience on initial installation is low out put at idle. This problem is easily solved with system upgrades that we describe below.
If you are not prepared to make needed system upgrades or feel you will not need to make those upgrades for whatever reason, please do not attempt this project.

High amp alternators are very RPM, WIRE GAUGE and BATTERY sensitive. These three things are absolutely necessary for optimum performance -

#1 - The positive battery cable to alternator MUST be upgraded to heavier gauge wire according to the amperage of the new alternator. Please refer to chart on the technical information page for correct wire gauge size needed.

WARNING - IF THE POSITIVE BATTERY WIRE IS NOT UPGRADED, YOUR NEW HIGH AMP ALTERNATOR WILL NOT FUNCTION CORRECTLY!!!

#2 - A smaller than stock pulley is used on the 200 amp and 250 amp alternators to achieve maximum output at engine idle speeds. A worn or stretched alternator belt that is working fine on your stock alternator will slip on a high amp alternator and cause a no charge or low output condition due to excessive torque created by the new high amp alternator. In some cases even a new stock size belt will slip.
For that reason, in some cases a shorter than stock belt is needed. This is not always necessary on the 160 amp and 170 amp upgrades.

WARNING - UPON INITIAL INSTALLATION OF YOUR NEW HIGH AMP ALTERNATOR, IF YOU HAVE VOLTAGE READINGS OF 12V OR LOWER AND WHEN YOU INCREASE ENGINE RPM THE VOLTAGE READING INCREASES TO 13-14V, YOU HAVE A SLIPPING BELT OR INCORRECT PULLEY RATIO OR BOTH.
**** WHEN YOU HAVE THESE SYMPTOMS, THE ALTERNATOR IS NOT BAD ****

This is why it is far better to find an OEM alternator with the desired amp capacity that will work on your car. Everything just *works*.

HOZZMANRX7

iTrader: (43)

^THAT is an excellent explaination that any layman could understand. Well done!!

Also explains why the physical size of a 100amp FD alternator is simply larger than an 80 amp S5 or 70 amp S4.

TheAbsence

iTrader: (19)

So it really sounds like the Taurus alt is the one for me.... the only issue I have is that I'm not sure it will clear my Mazdatrix 3 point strut tower bar.

meximan

iTrader: (37)

Thank you jack, thats the kinda info i was hoping for!

Jason, lets go get one, we can do it together :P As i dont have my car together to mock up fitment/wiring

JustJeff

iTrader: (13)

Thanks for the information Jack. Here is the modded Alternator I got.

140 amp alt

I haven't noticed any low voltage at idle. BUT I also have a brand new optima and also I've removed OEM and upgraded most of my battery and ground wiring.

IIRC I have:
4ga grounds

1. Battery to chassis
2. Battery to OEM ground location for starter through bolt
3. Engine to Chassis

4ga Pos (+)

1. Battery to alternator (B post IIRC)
2. Battery to starter
3. Battery to distribution block for amps (not that it applies to the alt at idle)

8ga Pos(+)

1. Battery to main fuse link in engine compartment

This post is a good reminder because I still have to remove the OEM wiring. It's disconnected but still loomed in with all the other wiring. I also have to research and find if I need to alter the wiring to the harness on the S5 alt.

For what it's worth I haven't seen any voltage lower at idle than I ever did with my OEM S5 or my FD alt. All of them sat near 12v at idle and picked up to 14v at around 3000-3500. The way it was explained to me that is normal behavior. Please advise me if that is not the case.

jackhild59

iTrader: (7)

Jeff-you are describing exactly the behavior that plagues rewind alternators.

At 12 volts your battery is discharging. A fully charged 12v battery is actually 12.6 volts, open circuit (no load). A 12 volt battery open circuit that measures 12.1 volts is considered to be 50% discharged. At 11.95v that battery is considered to be 75% discharged.

At 12volts, you are right on the edge of trouble!

Here is how it should work: You get in your 130 amp alternator sweetness-mobile. You start the car. This takes some electricity from the battery that must be replaced (if the battery is to be fully charged). The alternator provides 14.1 volts to the battery. And there it stays at idle, with the cooling fan running, the A/C fan running the stereo running, sub thumping. Everything gets 14.1 volts.


Think of it this way: all your accessories are designed to run at 14.1 volts. When the alternator is putting out 12volts, everything is running 15% slower/lower. Your fan runs slower, your fuel pump runs slower., your a/c fan runs slower, your amplifier makes fewer watts, your lights are dimmer, your ignition system makes 15% fewer volts etc.

If you spend most of your time running at 3000-3500 rpm that gives you 14.1 volts, you are golden. Most of us however spend lots of time at idle-sitting at a traffic light, sitting in the bank drive-through line, sitting at Sonic etc.

clokker

iTrader: (2)

This sorta implies you use your 7 as a car, like driving around in traffic and stuffs.
And I thought I was weird.

JustJeff

iTrader: (13)

Thank you for the explanation. What I find peculiar is that I have seen right around the same voltage at idle with all of the alternators I've used. Over the years I've had 2-3 different S5 alternators, an FD alternator, and now a modded S5 alt for 130 amps. I've had them in two different cars. They all show just over 12v at idle. If the RPMs go up to 3000 or so voltage jumps to 14v. The modded one does snap up much more quickly than the OEM ones. But they all have shown about the same voltage at idle....well if the OEM gauge is accurate.

meximan

iTrader: (37)

Just wanted to verify real quick before i start chopping up the harness, This is what i should be doing for a s4 Taurus alt upgrade. Excuse my Elementary school drawings

Taurus Plugs



s4 FC Plugs


And MY Elementary Drawings


Everything look right?

P.S..That gray cable was cut by the previous owner running a haltech...I have no idea what it goes to. any ideas?

jackhild59

iTrader: (7)

I would check it with Volt meter.

I changed from my S5 alternator because I couldn't carry the load of the Taurus Efan. Before the fan, my oem gauge read 14.1 volts. At Idle.

FWIW, my completely stock 04 Mazda6-S operates exactly as I described: 14.1 volts at/after start. When the battery is fully charged, it drops to 13.6v. I checked it today with a/c on high, rear defroster on, headlights/fog-lights on, stereo booming (amp and sub in the trunk) foot on the brake. I got 13.6 volts at idle. On this car, the voltage regulator is not old school, it is controlled by the ECU. This car has a 130 amp alternator from the factory.

dwb87

iTrader: (22)

meximan, your diagram seems to be correct. You can use the stock B+ wire for the Taurus alternator.

TheAbsence

iTrader: (19)

I'm down dude.

I'm sitting at 10 volts at idle :o

RotaryEvolution

iTrader: (30)

makes sense and i figured there would be a form of drawback to rewinding the stators, but i was having a hard time figuring out how the RPM was an issue.

JustJeff

iTrader: (13)

Jack, what you said was dead on..not that I doubted your advice. Just figured I'd report back. I was at my parents yesterday and let my father's 91 vert idle at around 500rpm. His OEM volt meter read 14v the whole time.

I've got my engine apart to have the injectors serviced so I can't test my alt with a multitester. But I'm stumped in that all of my alts have shown the same just over 12v at idle. For that reason I haven't noticed any different behavior from my OEM S5, FD and modded 140 amp S5. For the time being and foreseeable future my alt is going to remain the same. I know someone posted with a Taurus alt under their TMIC but I simply don't know how they did it. My FD wouldn't fit properly. I'd like to eventually go VMIC and at that time I'd gladly do a Taurus alt...but who knows if or when that will happen.

If I'm understanding the research I've done on aftermarket pulleys. The RB pulley and others are for slowing down the alt for high rpm/racing purposes. The exact opposite of what is needed for a H.O. alternator. Guess I'll have to hold rpms up a touch in traffic until I find a pulley.