I looked on Carcustoms.net and found this, but is this a set of underdrive pulleys or just one?
It is just the Crank Pulley.
dont buuuuy it killed my battery and alternator in two weeks, question did i have a system. Yea i did but a small one those pulleys according to them are good for a system up to 500 watts. plus there are little to no gains
frew wrote:dont buuuuy it killed my battery and alternator in two weeks, question did i have a system. Yea i did but a small one those pulleys according to them are good for a system up to 500 watts. plus there are little to no gains
Any under driven or lightened pulley will give gains.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
with the rk sport pulley do i need a smaller belt or no? i havent gotten to take a look at mine yet because it was just shipped yesterday.
I want to share something with you - the three sentences that will get you through life. Number one, 'cover for me', Number two, 'oh, good idea, boss', Number three, 'it was like that when I got here.'
Myles & Everyone Else,
That is a great question (about the smaller belt). I was wondering the same. I have a modified alternator to pump out quite a bit more amps for my audio system. Currently I need to get the RPM's above 3,200 in order to get the pulley turning quick enough to produce the higher amps. I need to get a new alternator pulley and am having a difficult time of finding out what size the factory alternator pulley is to begin with. Then I can figure out what smaller size pulley would be appropriate to put on to replace and speed up the revolutions on th modified alternator.
If any of you guys/gals know that answer to that it would be great. Then the next obvious questions would be (for those of you that have installed a smaller sized pulley) if you needed to swap to a smaller belt as well. Myles, when I talked to the professional alternator technician his simple answer was...put on the smaller pulley...if it sqeaks you need to get a smaller belt. That is obvious but if someone knows for sure it would be nice to budget in the price of a new belt.
Thanks everyone for help!
Excited New Member here
hey doug how did you modifiy the stock alternator to push more amps. im interested in getting mine done
Actually...I just brought it to a local shop that does alternator mods along with a bunch of other electronic related car parts. I didn't do it myself. I am located in MN. If you are from MN I can tell you where they are located. I can't even remember the name of the place that did it...its been more than 3 years since I was at their shop. I haven't had any problems with the mod'd alternator and like I said...I have had it for over 3 years. I have just been way to lazy to change the pulley...all I have to do is turn up the RPM's in order to get the juice...and usally I cruise at 2500+ RPM's anyways so it doesn't cause any issues.
Talk to the local car audio shops...they might now of a place near you. That is who tipped me off initally to the shop that I went to.
Doug
Doug Schmitz wrote:Thanks everyone for help!
First off, no one makes a smaller alternator pulley, Period. Inversely no one makes a larger crank pulley either, yet Both would spin the alternator shaft faster. Also there is very little room to shrink the alternator pulley. Trust me, there ain't really any room.
AEM makes a larger than stock alternator pulley, but thats not going to help you. Factory alternator pulley is 2.208" in diameter to the top of the pulley ribs.
Belt will be anywhere from 9.99-29.99 depending on band and design. I personally like gator back belts.
All under driven crank pulleys require a belt change to a smaller belt. RKsport, RSM/Z-spec, BOMZ, Unorthodox racing, and others all offer under driven pulleys.
If you want higher alternator output, you need to reduce the alternator pulley at the same ratio or more that the smaller crank pulley to produce just the same shaft speed or more of the stock set up. This isn't going to happen. Sorry.
In your case I would get a lightened stock crank pulley. Still have performance benefits, and will not slow your alternator. Currently I and RSM/Z-Spec are the only ones that makes stock diameter lightweight pulleys. I have none now, and RSM/Z-Spec.... If you get one good for you, nice product, bad shipping habits. They also pissed off a lot of members here. Try frankie Z on ebay he might have one or two left. He bought all the RSM/Z-Spec stock when the company went belly up AGAIN. He sells them for $30...I can not even get them made for that price.
Matt search in the Audio & Electronic forum. It has been disgusted a lot.
PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO
Mike,
Thanks for the response. A lot of good information there. I could be wrong here...but I just went on the NAPA website and found at least 3 different sized pulleys.
Now, unless I am missing something (which is very possible) the other universal Alernator pulley sizes I can choose from are: 2 5/8; 2 1/4; 2 13/32, 2 1/2. All of which are smaller than the 2 3/4 stock pulley size that I had A NAPA pull off of the shelf for me and check.
Did I get this wrong. You probably have more experience at this stuff than me.
Thanks!
Doug
I won't have a/c when I drop in the eco, and I cannot find the proper sized belt anywhere. I know the solstice belt works without the a/c, but I got no numbers on a belt size. Anybody got any clue?
I want to share something with you - the three sentences that will get you through life. Number one, 'cover for me', Number two, 'oh, good idea, boss', Number three, 'it was like that when I got here.'
call rk sport they will hook you up with the stock number for the goodyear gatorback belt that they recommend for the swap. With that number advanced auto can cross-reference the number you get you any make belt you want.
