1996 Buick LT1 alternator

Does anyone know the PN of the larger pulley for alternator PN 19152103 . I believe GM made two different
diameter alternator pulleys. I want to change mine (96 Buick Lt-1 ) to the larger size.
Thanks ed

Roadagon wrote:

Does anyone know the PN of the larger pulley for alternator PN 19152103 . I believe GM made two different
diameter alternator pulleys. I want to change mine (96 Buick Lt-1 ) to the larger size.
Thanks ed

Why??

I thought someone may ask that question,Inquiring minds and all that, well I am
going to a lower geared rear,plus I want to reduce the drag on the alternator by going
to a larger diameter pulley.

Sorry dude,but that makes no sense to me at all!To each his own,so go for it!Measure the pulley
width and shaft diameter and hit the junkyards.
Jim

Roadagon wrote:

I thought someone may ask that question,Inquiring minds and all that, well I am
going to a lower geared rear,plus I want to reduce the drag on the alternator by going
to a larger diameter pulley.

ah,. you're one of those,.

not worried about the p/s? the a/c ??

lemme know how it is idling in gear in traffic with all lights and accessories,. blower fan on high,.and wipers going .

mebbe you know something i don't,. i,m always willing to learn, and you certainly are a fountain of idea's,.

you understand how an alternator works right???

good luck with your search.

Nick

Ok guys, The larger size pulley that is offered by GM is only about 10-15%
larger in diameter. For those of us that have been around awhile,I'm not looking
for the type of pulleys that 60's and 70's stock and ss racers used that were like
3 times the diameter of the stock one. My Roadmaster gets pretty limited use,and
I doubt that I would ever be driving it in the type of conditions that I would need
my fan on high and all that other stuff going. Nick,I thought the p/s ran by hydraulic
power,and not electricity.Why would you say that a larger alt pulley would hinder
the power steering? So do any of you guys know the p/n of the larger alt pulley?
tks ed

Update on my 96 Roady wag.
Ok so I found an alternator pulley thats about 25% larger in diameter
then the stock one. I installed the pulley and while I was at it I also
added a volt meter gauge . To date I have driven around town for
maybe a hundred miles plus two trips to the New Jersey shore about 210
miles round trip for a total of approx 500 miles. At idle the gauge shows
about 12.5 volts and at cruise the gauge reads about 14 volts. So, for
all the nay sayers ; so far so good. I know it will take more time to
truly prove out ,but for now I am reasonably pleased with the experiment. ed

Roadagon wrote:

Update on my 96 Roady wag.
Ok so I found an alternator pulley thats about 25% larger in diameter
then the stock one. I installed the pulley and while I was at it I also
added a volt meter gauge . To date I have driven around town for
maybe a hundred miles plus two trips to the New Jersey shore about 210
miles round trip for a total of approx 500 miles. At idle the gauge shows
about 12.5 volts and at cruise the gauge reads about 14 volts. So, for
all the nay sayers ; so far so good. I know it will take more time to
truly prove out ,but for now I am reasonably pleased with the experiment. ed

well done,??

Not so much a nay sayer here,.i do believe you can, and you did, slow down the alternator,and again i reiterate that perhaps you might investigate the technology of an alternator vs a generator.

BUT,. perhaps you might need to see how much torque it takes to drive the alternator @ X rpm,.then how much torque at X rpm -25%,. this would give you the true value of what you have accomplished. I,m also curious to see what you think you have accomplished.

Nick

Nick, As far as accomplishments,nothing major,however I believe
I reduced parasitic drag somewhat and probably increased the life
of my alternator. These are really small things in the big picture
of how an automobile performs, but isnt that the goal of forums such
as this to identify small areas of performance. I am sure you are aware
of this , there are a few companies in the automotive aftermarket
that have carved their nitch making pully systems to free up
trapped power. ed

An underdrive pulley does no good except in the case where you are worried about over-revving the part in question. The alternator, for instance, takes 'full power' to turn at any speed when charging is being called for by the regulator. Underdrives are used when an engine is expected to rev over 6-7 grand, which is more than the accessories were designed to put up with (and may 'grenade', so-to-speak).

Jimbeau; Are you saying there is no gain in HP when you underdrive the accessories? ed

Roadagon wrote:

Nick, As far as accomplishments,nothing major,however I believe
I reduced parasitic drag somewhat and probably increased the life
of my alternator. These are really small things in the big picture
of how an automobile performs, but isnt that the goal of forums such
as this to identify small areas of performance. I am sure you are aware
of this , there are a few companies in the automotive aftermarket
that have carved their nitch making pully systems to free up
trapped power. ed

under drive pulleys are used to slow down pumps,. they are usually sold in matching pairs, the smaller pulley of the set is then added to the alternator so it can turn optimal speed for charging even at low crank rpm,.

I,m not a qualified anybody, but i can tell you the miniscule amount you might have added to the life of the bearings of your alternator, in my opinion does not justify the cost/benefit for this time you have invested in sourcing,purchasing and installation,
perhaps a complete belly pan added to the bottom of the car might produce better gains?

Again i think you might not have a complete grasp on the differences in technology between alternators and generators.

To do a proper scientific comparison, the car should have been run thru a few controlled test cycles to setup a baseline, then the exact same test cycles with the larger pulley,

No where in your theory have i seen the correlation explored between amps and voltage,.with the larger pulley etc,.

you are asking the alternator to produce its amps at a lower rpm, which in fact may take more power from the engine, it may also contribute to the alternator running warmer than necessary due to the cooling fins turning slower, which i could surmise that the alternator would indeed wear out quicker and use more fuel if it,s run a lower than its optimal rpm,.

another engineer out engineering the engineers?

I can't say for sure,. but i will say again,. in my humble opinion its a complete waste of time and effort.
and in my opinion is detrimental.


Nick

Roadagon wrote:

Jimbeau; Are you saying there is no gain in HP when you underdrive the accessories? ed

I can't see ANY significant gain on the alternator. PS pump, sure, but my guess is that the stock pulley is designed to be as slow as is practical because they don't want the pump running any faster than it HAS to. The all-important CAFE standards make the manufacturers try to squeeze the most efficiency out of accessories as possible. If you lowered the speed of the PS pump, my guess is you'd lose it at idle. AC compressor? Sure, you'd gain some HP, but it wouldn't do any compressing at idle, so what have you gained?

Nick, In response to your post of earlier this afternoon about my non standard diameter alternator pulley, It sounds as if you have more concern and compassion regarding my
alternator then you do about berating someone in public. Fortunately there are few
forums out there that contain a member such as you.Although I am relatively new to
GM Longroof,it didnt take me long to figure out your " game ". You try and draw your
victim in and allow them just enough rope to verbally hang thenselves,then you pounce
and embarrass them in front of all the members. How dare you take a vehicle such as
this forum, thats supposed to be for learning, enjoyment of the automobile hobby and
possibly even making some distant and local friends and turn it into your personal
shooting gallery. You state that my experiment was a waste of time and the cost and effort
of it much out weighed any good that could ever come of it. To everyone on this Forum,
I am sorry that I shared this experiment with you and I also apologize for wasting your time. There are several other GM forums out there where you dont get blasted for telling
the members about your thoughts and ideas. Nick,lets say you are correct about my experiment, First off, I dont believe I
harmed anyone during it,I dont think it was illegal to perform and possibly someone however remote my glean some knowledge
from it. Nick think of it ,if I start an epidemic, in no time at all you will have the forum to yourself!

Roadagon wrote:

Nick, In response to your post of earlier this afternoon about my non standard diameter alternator pulley, It sounds as if you have more concern and compassion regarding my
alternator then you do about berating someone in public. Fortunately there are few
forums out there that contain a member such as you.Although I am relatively new to
GM Longroof,it didnt take me long to figure out your " game ". You try and draw your
victim in and allow them just enough rope to verbally hang thenselves,then you pounce
and embarrass them in front of all the members. How dare you take a vehicle such as
this forum, thats supposed to be for learning, enjoyment of the automobile hobby and
possibly even making some distant and local friends and turn it into your personal
shooting gallery. You state that my experiment was a waste of time and the cost and effort
of it much out weighed any good that could ever come of it. To everyone on this Forum,
I am sorry that I shared this experiment with you and I also apologize for wasting your time. There are several other GM forums out there where you dont get blasted for telling
the members about your thoughts and ideas. Nick,lets say you are correct about my experiment, First off, I dont believe I
harmed anyone during it,I dont think it was illegal to perform and possibly someone however remote my glean some knowledge
from it. Nick think of it ,if I start an epidemic, in no time at all you will have the forum to yourself!

What perplexes me is it took you so long to get to this point where you are now embarrassed,

I,ve tried to give you the opportunity to read up on ac and dc current,. amperages etc,. yet you,ve chosen to plow on down a path that to me personally seems a complete waste of time,.
I,ve been careful to add to my posts that i,m not qualified to make a scientific judgement,. and it,s simply my opinion,.
I stand by my opinion, which is this whole exercise of yours has been unproductive and not cost efficient,.it doesn't even have a "cool" factor to offset it,.If my opinion is that damaging to you,. i suggest you turn in your man card,.its obviously doing you as much good as your engineering certificate,.

If you feel berated,. well ok i'll apologise,.

vilifying me for saying "the emperor has no clothes" is quite common,. i,m used to it,.

You yourself are guilty of baiting,. asking jimbeau a reverse onus type question,about horsepower and under driven accessories,. so acting all holier than thou doesn't cut it .

Kudo's for your tenacity, in pursuing your questions in life,.
yet at the same time are you tenacious? bull headed? or in my opinion just not smart enough to research a project before you execute it,.or to listen to different opinions , thoughts, or advice,.

I did notice a common denominator in the replies to you,. from jimbeau flasheroo and myself, all guys with plenty of experience around cars, and well schooled in redneck engineering, guys secure enough in their knowledge to speak up ,.


At no time were you accused of anything dangerous, or illegal,. these are your words looking for sympathy,.the only time you,ve wasted is your own,.and you,ve gained my opinion (and a couple of others) for free,.

I wish you all the best in any future automotive modifying endeavours,.i will find them fascinating i,m sure,.
and i,m sure somewhere someone will glean some knowledge from them,. possibly not to do as you have done,.

Lets hope we don't have an epidemic of slow turning alternators out there,.that are arcing madly trying to produce ac electricity at less than optimal speed,.

Oh and for your info,. if with the car running at idle you are producing only 12.5 volts,. you are draining the battery,., with full electrical accessory load, your car will definitely be discharging the battery at idle,.
I.E heater fan on high,. headlights on, wipers on,. and defrosts both on,.

Best of luck,.

Nick



I

@Roadagon: My info was just for discussion and clarification purposes.
There is nothing wrong with you screwing around with your car; it's what we ALL do.

Yep its been some time since I posted , I wanted to give, anyone that was interested,
some details concerning the long term testing of my alternator with the oversize pulley. Took the wagon on a trip to Maine approx 1300 mile round trip, I did make sure the battery was fully charged before we left. Alot of the trip driving was done at night and in the early AM. We used the heat ,AC ,defrosters,wipers,headlights, and anything else that we needed to stay
relatively safe and comfortable during the trip. I tested gas mileage only once during
the trip and I am pleased to say that we got a little over 23 mpg, I figure we had about an 800 lb payload and thats including the 2 passengers. Anyway the alternator performed
adequately during the 10 days that we were up there. I dont know if anything was improved or degraded because of my pulley swap,but nothig catastrophic occured due to the alternator/pulley combination. ed

These wagons if driven at normal speeds and no racing will easily deliver 25mpg and even more
if you really are careful with the go pedal.Wish you had taken this trip with the stock pulley
installed and again after replacing it to see if your mileage was really effected.Best of luck and dont be such a stranger.

Hi Flash; I am pretty sure the addition of the larger alt. pulley was pretty insignificant
regarding fuel mileage.
I would be really surprised if it did that much. I do know that it did reduce
parasitic drag a small amount without adversly harming the charging system.