So I was running the J-tune underdrive pulley on my car and noticed at idle the car only puts out 11.8-12.2 volts, and around 13.5-13.8 when driving. Is there anything out there to bump the voltage up? Maybe a smaller alternator pulley to speed up the alternator to keep the speed the same?
2009 Ford Mustang V6
look into the AEM alternator pulley. I may be mistaken but if I remember right its a smaller pulley to make the alternator spin faster when using an underdrive crank pulley.
I think AEM is stock size. Either way, the J-tuners alt pulley was oversized pretty big, so running the stock sized alt pulley would bump that up anyways.
Or you could look into redoing the alt to accomodate. I had an org member re-do my alt to put out some serious power due to my electrical demands, perhaps they can do something to up your voltage, like install an adjustable voltage regulator or something.
I dont know what all electrical equipment you are running in your car, but if its anything more than factory, I would def. consider doing a high ouput upgrade anyways.
Darkstars wrote:look into the AEM alternator pulley. I may be mistaken but if I remember right its a smaller pulley to make the alternator spin faster when using an underdrive crank pulley.
The AEM pulley is
oversized / underdriven. The J-tune Alternator pulley is also
oversized / underdriven.
If I were you I would get a stock sized alternator pulley. ~~Cough Cough~~ Or try and find a smaller than stock alternator pulley.
Ryan, The LD9 AEM underdriven pulley was designed to be used with the unorthodox LD9 underdriven pulley, so a stock length belt could be used.
Edited 1 time(s). Last edited Tuesday, January 06, 2009 9:02 AM
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
This is when I run just the underdrive crank pulley and the stock alternator pulley. The alt overdrive makes it even worse.
2009 Ford Mustang V6
Get a smaller / overdriven alternator pulley....or a new designed alternator.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
The01Cav wrote:This is when I run just the underdrive crank pulley and the stock alternator pulley. The alt overdrive makes it even worse.
That doesn't make much sense, unless the two undersized pulleys are causing belt slip.
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nope, it makes my power steering lag some, and the coolant temp even runs slightly higher with the underdrive pulley.
2009 Ford Mustang V6
its nothing that hasn't already been proven in the past.
your slowing down the alternator with the smaller crank pulley. your slowing it down even more with the larger alternator pulley. so in turn, no.. the alternator isnt going to be putting out much at idle.
my advice:
try the big three upgrade first, if it doesn't improve things then get a better battery. if that doesn't help locate the dood on here thats selling the high output alternators that output MORE then stock at idle instead of the LESS then stock at idle high output versions out there. and ultimately if that doesnt solve the issue, time to ditch that pulley in favor for an
MD LD9 stock sized aluminum one.
for the difference in power output the MINUSCULE gain isnt worth it. stock sized pulleys do just as much as the underdrive ones, the help comes from them being LIGHTWEIGHT, not the underdriven part. and in all reality, mike's alternator pulley is probably lighter then the J-tuners OR the AEM because its smaller. but for gods sakes here... its like 3 ounces lighter than stock. if you can feel a difference in power from 3 ounces you are a god and need to be floating above us.
Edited 1 time(s). Last edited Tuesday, January 06, 2009 11:45 AM
Are you scared of the changes coming? The answer is on the inside.
^^^Brad I see what you did there.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
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what u sed was the answer. but u dont want aem or anything. those are to underdrive the alternator as well for hp. needless to say thatll make it worse. i dont know if anyone make a pulley to speed up the alternator.
maybe machine it to a smaller diameter
dont worry about the voltage not a big deal
tune ur ecu for higher idle
Working on obtainting an M-Class license... ?? Hint: 2 wheels.
hey josh... didnt you end up getting a SMALLER than stock alt. pulley??? IIRC u bought like three different sizes, yes?
Are you scared of the changes coming? The answer is on the inside.
z yaaaa wrote:hey josh... didnt you end up getting a SMALLER than stock alt. pulley??? IIRC u bought like three different sizes, yes?
This is true. I got a HO alt from Motor City Reman, which came with a smaller pulley. I ended up getting a second pulley that was even smaller. (The final size is 1.75" diameter, if I recall.) So I should have both a stock pulley and slightly smaller than stock pulley lying in the garage someplace. The only catch was they claim there aren't suitable undersize pulleys for this application that have the correct number of ribs, so both small pulleys have an extra rib next to where the belt sits.
The 1.75" pulley.
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i see! well i guess some could leave that extra rib hanging out while others would get annoyed with it.. like me LOL
-
Mike
Davis- LD9.. time to make a
smaller alt. pulley for us.
Are you scared of the changes coming? The answer is on the inside.
-MD- LD9 wrote:Darkstars wrote:look into the AEM alternator pulley. I may be mistaken but if I remember right its a smaller pulley to make the alternator spin faster when using an underdrive crank pulley.
Ryan, The LD9 AEM underdriven pulley was designed to be used with the unorthodox LD9 underdriven pulley, so a stock length belt could be used.
I knew it was supposed to be used with an underdrive pulley I never thought they would use it to slow the alternator down even move. That just seems stupid LOL
^^^ anything to sell a part, aye?
Are you scared of the changes coming? The answer is on the inside.
z yaaaa wrote:i see! well i guess some could leave that extra rib hanging out while others would get annoyed with it.. like me LOL
Lucky for me, my bone-stock engine bay only gets opened when the coolant is down every few weeks.
I've watched to make sure the belt behaves and "tracks" well despite the extra pulley width, and it's given no problems since last fall. This definitely is an option for idle charging problems, if it's not a show car.
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z yaaaa wrote:i see! well i guess some could leave that extra rib hanging out while others would get annoyed with it.. like me LOL
-Mike Davis- LD9.. time to make a smaller alt. pulley for us.
How small?
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
-MD- LD9 wrote:z yaaaa wrote:i see! well i guess some could leave that extra rib hanging out while others would get annoyed with it.. like me LOL
-Mike Davis- LD9.. time to make a smaller alt. pulley for us.
How small?
i would like one as small as you could possibly get it
X2 here bro. i would benefit from it the most because my 180 amp insides dont charge as much as a stocker at idle.
on size... no idea where to even begin. i spose we probably should find out how fast the alternator can spin safely and not ruin the bearing to determine that, yes?
although.. i have aftermarket 180 amp guts inside mine so i have absolutely no idea if mine would be ok or not. i can call the shop that did it to check though...
Edited 1 time(s). Last edited Wednesday, January 07, 2009 12:51 PM
Are you scared of the changes coming? The answer is on the inside.
The one I ended up with seemed to be the smallest standard size offered by Motor City Reman (and was smaller than the already small pulley they included in the first place). Based on this, I'd recommend 1.75" as a guideline for an lower limit on smallness.
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....Just getting replies emailed to me....
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
I think the crank pulley I have is 25% under driven, so would the same theory work on the alt pulley of dropping it in diameter by 25%?
2009 Ford Mustang V6
