pulleys
pulleys
Can someone explain to me the whole under pulley/unorthodox pulley thing? Do you just simply replace the stock pulley with the new one, or what? and how do they help? Im sorry to seem so clueless on this subject, but I would like some straight information on this upgrade. Thanks in advance!
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juazam_186
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Nismo_Freak
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Well if for some chance it didnt have it. Yes you just replace the stock pulley with the new lightweight pulley on the crank. Works best with a crank pulley puller tool and with the removal of the mechanical fan. If you live in a cool climate and dont use the A/c often then there is no real need for the mechanical fan. Just switch the electric fan to the primary and make it come on when the coolant temp reaches a certain degree. For insurence you can get a new high pressure radiator cap and dual T-Fal fans.
That really isn't true, eliminating equal reciprocating mass shouldn't throw anything off. If you just cut a chunk out of the existing one THAT would cause unequal balance. Think about it, a rotating crank and pulley, coupled with a driveshaft, would not wear unevenly if you did anything unilaterally across a device. For example if you shaved an eigth of an inch off the driveshaft the whole way around evenly then it would be balanced. An Underdrive pulley is primarily what the name says, a pulley that provides about 15% less spin to all your accessory pulleys, however all these are overshot anyway and can deal just fine with that loss. And if you know about the law of reciprocatin mass you know that nothing can help an engine spin faster than lightening the parts that have to spin. ASP makes a pulley that is pretty much the same as the Unorthodox and is cheaper.
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Daunttless
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I didn't read to closely, so excuse me if its been answered already. But basically an underdrive pulley does exactly what it says. It underdrives the pumps and alternator. This is good because it means that theres less power going to them, but its bad if you do things like big stereos or what not, as your alternator will not be providing enough charge to adequately refresh your battery. Also, its not about unbalancing, that was a problem with the original pulleys, now its a problem with the harmonic balancing. : ) A lot of people have problems with the vibration prone KA and underdrive pulleys. Also, you'll need all new belts and what not to use, and I can't remember the codes for them, but they should be on 240sx.org. : ) Good Luck!
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Daunttless
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MaineExport
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While the power reclaimation is noticable, don't expect too much. The underdrive will lighten the "reciprocating mass" and the electric fans will take some of the load off the engine. I wouldn't bother removing the A/C. Unless it is turned on, it really doesn't offer much resistance.SPIRO wrote:I plan on installing an underdrive pulley, removing my a/c, and replacing my mechanical fan with 2 elctrical ones. I hope to gain a decent anount power back from all of this, but would having this done cause any other problems or is it a 100% good idea? Thanks in advance.
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240sleeper
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Pulley and Compressor????
Hi I just had a major a/c compressor failure and had a remanufactured one put in and I would like to know if slowing down the compressor by installing a pulley would harm it. Remember I live in Phoenix:rolleyes Thanks
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MaineExport
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Installing an underdrive pulley shouldn't have any adverse affects on the A/C compressor. Basically it's just going to be running the unit as if you were driving at a few less RPMs. Such a small decrease won't be noticable. If anything it might increase the life of all the moving parts, as they are spinning fewer times.... just a thought.
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ash1y1
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Pulleys
Ok guys probably yet another dumb question, but since I don't know much, I'm going to ask it anyway.
On my automatic 95SE, is it a good idea to replace with electric fan and get the crank pulley and CAMs? I do have a couple of subs and 2 amps, but aren't really running that much juice. Tell me what you guys think I should do.
Also, I should be receiving my new intake system and extension. What should my second purchase be, third purchase be, fourth and so on. If someone could put together a nice list for me that would be AWESOME! And please list parts that should be bought together next to each other. Thanks
On my automatic 95SE, is it a good idea to replace with electric fan and get the crank pulley and CAMs? I do have a couple of subs and 2 amps, but aren't really running that much juice. Tell me what you guys think I should do.
Also, I should be receiving my new intake system and extension. What should my second purchase be, third purchase be, fourth and so on. If someone could put together a nice list for me that would be AWESOME! And please list parts that should be bought together next to each other. Thanks
Flip240, I installed the UR pulley, was it worth it, I guess. Was it hard to complete the mod, I thought it was, but some of that was due to my 97 being an automatic. I am glad I did the mod even if just for the experience.
btw, while your doing the job change the front seal. The seal is only $6 -$10 bucks.
Emperor, I also have the other 3 pulleys from UR but have not installed them. Not sure if they will make a big difference but I wanted to have the complete set. Depends on you goals I think. My car is more show than go......
btw, while your doing the job change the front seal. The seal is only $6 -$10 bucks.
Emperor, I also have the other 3 pulleys from UR but have not installed them. Not sure if they will make a big difference but I wanted to have the complete set. Depends on you goals I think. My car is more show than go......
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skydragoness
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92' 240sx 60k survivor :) - Location: North DFW, TEJAS
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ehhhh...
i've somewhat crossed off underdrive pulley from my list of mods for the KA, based on the product reviews i read on 240sx.org, for there to be any doubt that it affects the KA's harmonic balancing makes me wonder if it's worth installing...and most of the more 'positive'reviews of the pulley didn't seem to make that much of a difference in power delivery, hence i'm not doing it. Besides, if i keep the car as long as i plan to, i'll be throwing in the SR, much, much, much, much later.
It should make a difference(that is why god invented gears), the most common problem is that people get used to it very quick, a lot of people use only the butt-dyno to guess HP gains from mods.
it's difficult to do a list of the actual path of mods, we can all chip in and see the basic mods and do "stages for mods" but that is a big discussion all by it self.
Who says a $300 header is stage 1 or stage 2?What you want to do in the long run? FI or NA.
You get the drift right?
When you mod your car, everyone will tell you "Since your changing this, do this also and this" and a simple $100 mod will turn in to a engine overhaul in no time, just plan everything and do the things yourself(if you can) and if you have to do it again to change something else do it again. Unless you have the money of course...
it's difficult to do a list of the actual path of mods, we can all chip in and see the basic mods and do "stages for mods" but that is a big discussion all by it self.
Who says a $300 header is stage 1 or stage 2?What you want to do in the long run? FI or NA.
You get the drift right?
When you mod your car, everyone will tell you "Since your changing this, do this also and this" and a simple $100 mod will turn in to a engine overhaul in no time, just plan everything and do the things yourself(if you can) and if you have to do it again to change something else do it again. Unless you have the money of course...
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allthrottlenobottle
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underdrive pulleys are a great mod because they are horsepower gain for cheap. Most pully kits only need shorter belts installed. the reason for the shorter belt is to apply the same tension as stock belts. Some setups do not even require shorter belts.
Dauntless is right on the money with what they do and how they work. Sometimes charging rate goes down at idle and i've never seen it down at higher rpm's.hence the shorter belts to compensate.
Dauntless is right on the money with what they do and how they work. Sometimes charging rate goes down at idle and i've never seen it down at higher rpm's.hence the shorter belts to compensate.
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