Thank you for the advice. That is why I wasn't considering anything bigger (well that and the pulley size decrease that some have stated causes the belt to slip).

I really wasn't sure what output level would dictate an upgrade such as the external rectifier.

 

I think this is an even better read on the same subject/company. WARNING--some of the language is graphic

Calling B.S. on all these HO alternators

 

Yeah, I just read all 16 pages. I suppose I am sold on the DC alternator.

I used to know our alternator pulley size (wrote it down somewhere). Anyone know what it is? I was told that the F series ratio is 2.8:1

 

Depending on which part of the pulley groove you measure 2.625" for all intents and purposes.

 

Stock is 2.73" according to this:

6.0L Diesel Alternator Overdrive Pulley [GGD-ODPulley8] - $75.00 : Direct Injection Performance - GoGoDiesel.Com, Your Source For All Things Diesel!

 

Thanks Tim / cartmanea.

Looks like the DC alternators are on sale ........

DC Power alternators for 2003-2007 F250/350/450/550 Super Duty pickups with the 6.0L Powerstroke diesel

Sarge (or William) - did William upgrade any wiring for the 190A alternator?

 

Nice--I didn't do too bad for a "guess" as I didn't really know where to measure. Well......if Doug has it for $75 then it can be purchased cheaper somewhere else, so lets get to looking gang.

It would also be nice to know what size DC's alternators come with as they reference a "custom" pulley and their alternators are rated at alternator RPM's not engine RPM's.

 

Looking at the stuff you are thinking of buying, and the most obvious omission is any reference to duty cycle as designed.

So we don't know if it is 200a rated, but duty cycle of 100% (all the time - unlikely) or more likely, 50% time or less.

There is also no performance data correlated to temperature --- critical.


The key to buying right is to balance your actual duty cycle / load profile with the alternator, add a bit of safety margin, and then... hope you guessed right.

Remember --- power demands never stay the same, but grow as a vehicle age from poorer contacts, added electrical gadgets, etc.

So safety margin going in is money in the bank for future reliability.


There are two major determining factors beside underhood temperature.

A) what is the actual load / duty cycle?

B) what is your peak load?


If you are looking for a high percentage of the rated (e.g. 150a continuous) then you really need the capacity.

Motors like starters are very high output, but very low duty cycle.

Alternators are not expected to do much higher than 50% rated output over more than, say, 25% of the duty cycle.

So add up all your loads, and if you are even close to 50% duty cycle, you need more than the standard alternator.

IMHO, the external rectifier is such a no brainer (cooler, add "free" capacity by cooling the most heat sensitive part), that I strongly recommend it for:

A) warm climates (e.g. Texas)

B) any load profile above 50% rated for more than 25% of the time.

Often, you cannot predict the times when your electrical load peaks out at the same time as you hit peak temperature.


If it would help your decision --- I put in a 145ish amp custom built (tow truck) alternator in my van without an external rectifier.

But,

a) I am operating in a cold climate most of the time.

b) I anticipate peak loads of 100a about 50% of time (e.g. charging house batteries plus all electrical accessories running, with some bling bling working like computers and electronics.

c) I have very little room (E series).

d) it may only be rated 145ish amps, but it is also rated to pull over 100 amps continuously, whereas most standard alternators peter out at more than 50% rated capacity for any length of time.


To help you make your decision --- talk to local high "hotel load" usage people like ambulance, tow truck, police, etc. and see what they are doing.

Don't waste much time with the dual alternator people --- real difficult balancing 2 alternators on one circuit even with factory ECM --- or with those who have a dedicated 2nd alternator to house batteries. They are irrelevant to you.

Talk to the people that are running everything on one alternator, and you will very quickly find what is right in your climate.


To me, to run electronics cool is to do the same as changing oil no later than the recommended interval --- the cheapest insurance you can buy.

Enjoy!

 

You also forgot to mention that the input shaft and the solonoid that is in the direct clutch is a weak point as well. One of the reasons why incorrect(or off the shelf tuning) does not do very well. These were later addressed in the tranny behind the 6.4 as it can handle significantly more power without needing to be rebuilt.

 

Mark:

This link below gets you to a big PDF document with a lot of valuable data that should be on the Tech Folder:

http://wpnet.us/2009-Electrical.pdf


Specifically, I draw your attention to the output / rpm / temperature curves for nearly every commonly available Ford alternator.

P. 17 have the curve for the 200amp alternator.

Note how much output changes with temperature ---

If you can keep the key part cool (rectifier), you get most of the output lost to higher temperatures.



The publication here is for sizing alternators for Ambulances:

http://dimensions.sensata.com/Applic...otes/An107.pdf





The weakest part in your alternator is the electronics:

http://www.st.com/stonline/books/pdf/docs/1368.pdf

Note on page 2, the voltage regulator IC have an absolute maximum temperature of 140C.

That temperature is easily exceeded on a hot day inside the alternator case.

When you get close to that temperature, the IC basically shuts down the alternator gradually.

 

I searched on that site on the terms "alternator duty cycle"

Apparently that was not mentioned in the thread...


Our average diesel starter is a 3 to 4kilowatt unit.

The catch: don't try to use the starter more than 20 times a day.


It is very possible to get large "peak" outputs from what appear to be smallish alternators.

On the bench, you will get outsized output --- 300a etc.

But try to deliver anything close to that on a sustained basis, and you are toast.


Given that the average 6.0 owner actually have high charging needs (glow plugs, fuel module, high amp starter) all consume gobs of electrical power that have to be replaced (charged back into batteries), the duty cycle profile of a diesel 6.0 is that much harder than a equivalent V 10 gasser.

Whats more, inherently, we load our trucks up with electrical bling bling --- from the inverter inside, laptop computer, navigation, heated seats, TV, radio, phone....... all this stuff have to be operated.

When I did the calculation on mine (Van with house battery to be installed), I came up with a sustained load of 150 amp while charging house batteries --- and that is with careful power rationing to ensure I don't overload the peak limit.

Once the batteries are charged (car and house), I am down to 100A or so --- leaving a safety margin of nearly 50% with a 145a alternator.

That is why I went for a 145a tow truck alternator that is able to put out close to its full load on a continuous basis.

Don't get to brag about my 300a peak output... but I can do 140 probably all day, while the 300a peak job might die with 120a continuous.

 

Mark I dont think he changed any wiring. The only thing I know is that he bought a polished one. Other than that there was no mention of a wiring upgrade to make this work properly.

I read the DC sstuff too and I am glad we waited and didnt jump on it last year when we were hot to trott LOL

 

The easiest way to do a wiring upgrade from the alternator is to add a power cable and ground strap / wire in parallel to the existing one.

However, the wire should be properly fused with a fusible link.

 

I haven't changed any of the wiring, and haven't seen a need to yet. I'll run some tests on mine today and see what it's really putting out. I can put a decent load on it. I'll measure the pulley for you also Tim.

 

A quick test showed 132A output at idle after driving all morning. This was with both HVAC blowers, (2) HFCM's, a Viair 480C compressor, and head/fog lights on. I'll throw up something more detailed later.