UR Pulley personal opinion's
02-23-2010, 11:04 AM
#41
Intermediate
This will be the only response to this thread UR will make. Every angle the naysayers try to bring up has been covered in our FAQ on our web-site and in our blog which is linked from our site.
Everyone is entitled to their own opinion so those not willing to do this mod, don't do it if you are more comfortable. Anyone that doesn't agree with their decision not to use this product needs to mind there own business. Sure would I like to change their mind, of course but like with anything in life you win some and you lose some and some people will never change.
Dave_B you are nothing but a trouble maker with no basis for anything you say. Your opinion is just that, an opinion. You are the only person we are aware of that has ever seen a reduced 60' time from loss of rotational weight. You are also the only person we are aware of that can on one hand praise the laws of physics and on the other hand disprove them with completely unscientific your testing. The amount of mass required to hurt a launch is atleast twice the weight reduction of our pulleys, 8-10+ lbs.
Weight loss will yield an improvement in ET at any distance. Statis weight reduction needs to be significantly larger than rotational weight redcution but each will yield a corresponding drop in ET. If you dis-agree then take it up with Newton and hundreds of years of scientific data.
Your snippet about how we now say all cars use a damper is soooooo far out of context its laughable. Are you sure your not a journalist? Cause you took what you wanted out of the blog without even mentioning how we specifically rule out the need for a damper on all the sport compact vehicles we make pulleys for. Good job! I hope people finally see you as the trouble maker you really are
If you are so adamant about your claims then why don't you pay an independent lab to dis-prove us and the tens of thousands of happy UR customers that have their own dyno sheets and butt dynoes and improved tme slips. We don't have anything to prove because after 14+ years in business the market has proven us to be worthwhile and in fact aside from boosted cars that get programming or exhaust work our pulleys are the highest HP, per dollar spent, gain in the entire aftermarket.
Oh and one last thing I almost forgot. If 350z/G35 guys think our product is snake oil then why are those parts our best selling pulleys? Makes you wonder what Dave_B is talking about!
Respectfully,
Shawn Baumgartner
Everyone is entitled to their own opinion so those not willing to do this mod, don't do it if you are more comfortable. Anyone that doesn't agree with their decision not to use this product needs to mind there own business. Sure would I like to change their mind, of course but like with anything in life you win some and you lose some and some people will never change.
Dave_B you are nothing but a trouble maker with no basis for anything you say. Your opinion is just that, an opinion. You are the only person we are aware of that has ever seen a reduced 60' time from loss of rotational weight. You are also the only person we are aware of that can on one hand praise the laws of physics and on the other hand disprove them with completely unscientific your testing. The amount of mass required to hurt a launch is atleast twice the weight reduction of our pulleys, 8-10+ lbs.
Weight loss will yield an improvement in ET at any distance. Statis weight reduction needs to be significantly larger than rotational weight redcution but each will yield a corresponding drop in ET. If you dis-agree then take it up with Newton and hundreds of years of scientific data.
Your snippet about how we now say all cars use a damper is soooooo far out of context its laughable. Are you sure your not a journalist? Cause you took what you wanted out of the blog without even mentioning how we specifically rule out the need for a damper on all the sport compact vehicles we make pulleys for. Good job! I hope people finally see you as the trouble maker you really are
If you are so adamant about your claims then why don't you pay an independent lab to dis-prove us and the tens of thousands of happy UR customers that have their own dyno sheets and butt dynoes and improved tme slips. We don't have anything to prove because after 14+ years in business the market has proven us to be worthwhile and in fact aside from boosted cars that get programming or exhaust work our pulleys are the highest HP, per dollar spent, gain in the entire aftermarket.
Oh and one last thing I almost forgot. If 350z/G35 guys think our product is snake oil then why are those parts our best selling pulleys? Makes you wonder what Dave_B is talking about!
Respectfully,
Shawn Baumgartner
Last edited by unorthodox; 02-23-2010 at 11:08 AM. Reason: One last point I fogot to add
02-23-2010, 12:40 PM
#42
Three Wheelin'
As I said I personally don't like the mod because of my previous pulley I bought from another manufacturer. The woodruff wallered out the friggen opening and decided to weld itself to the bolt somehow. It could have been because of the crappy materials built into it but I like the factory my preference since I can use my tool to pull it off quick. But anyway my friend has one on his v6 accord he says he likes it. Not my kind of mod but for those that need a easy, quick mod thats the way to go. Its nice that UR actually provided that statement as I recall that has been on there for quite a while since quite a bit of people were questioning about internal dampening etc. If I was to do anything I would do the surrounding pulleys other than the crank.
02-23-2010, 12:47 PM
#43
Pro
Join Date: Sep 2005
Location: Charleston
Age: 49
Posts: 706
Likes: 0
Received 0 Likes
on
0 Posts
How about gas mileage, wouldn't it improve slightly?
I have never heard anything bad about UD pulleys, the problem is with insufficient cooling with the addition of high hp mods. The TL doesn't have this problem. It is worth it for better throttle response and over all better performance.
I have never heard anything bad about UD pulleys, the problem is with insufficient cooling with the addition of high hp mods. The TL doesn't have this problem. It is worth it for better throttle response and over all better performance.
Last edited by Bender; 02-23-2010 at 12:49 PM.
02-23-2010, 02:55 PM
#46
Burning Brakes
Wow. That's pretty weak, Shawn.
It's laughable to you don't understand the physics of the very part you sell. It's called moment of inertia. Go back, research it, and then get back to me. Here, I'll make it easy for you http://en.wikipedia.org/wiki/Moment_of_inertia
Here's a simple test to prove what I'm saying. Take a 8" peice of string and connect it to a 1lb weight. Then take a 20" peice of string and connect it to a 1lb weight. Grasping the strings, spin the weights. You'll see that it takes a lot less force to start spining the weight attached to the 8" string and to keep that weight in motion. The point here is it's take a lot less force to spin a smaller diameter, same weight object. The same applies to your pulleys. Sure, you're removing weight, but it's a mass of weight that has a small diameter and it mounted directly to crank.
I've done the math and reducing the pulley weight to the degree that you do, will result in a realized gain of approximately 4hp in 1st gear, 2.5hp in 2nd gear, 1hp in 3rd gear, and .5hp in 4th gear. Over the span on a 1/4 mile run, the "gains" are basically worthless in a 3000lb+ car.
I am surely not only avid drag racer that has not posted an improvement in 60' time with your pulleys. I've been drag racing for over 15 years now and have drag raced domestics like Stangs and F-bodys, sport compacts, and import sedans. I've got over 500 passes under my belt and I fully understnd the physics and techniques behind drag racing. You fail to understand that in a drag race, you want some amount of moment of interia because without it, makes a car harder to launch and far more prone to bogging. It's the main reason why you don't see drag cars running lightened flywheels. Lightened assemblies like flywheels suck for drag racing, but are good for road racing because it's easier to rev match a downshift which reduces chassis movement. What applies to road race cars doesn't necessarily apply to drag cars. This is where much of your "opinion" is flawed.
Again, it greatly depends on where the mass is.
Regardless, for years you have vehemently denied that OEM pulleys were dampers and that the elastomer ring was simply there to quiet accessory noise. Now your tune has changed and fully admit that OEM pulleys are in fact dampers. Your loosing this argument, Shawn.
Did you miss my previous posts where I said put your pulley to the test both on the strip and dyno? I can post other dynos of Maximas and G/Zs showing no gains with your lightened pulley as well as other makes which are the same exact thing. A majority of G/Z and Maxima crowd put lightened pullies up there in the same ranks as The Tornado and throttle body spacers.
Dave_B you are nothing but a trouble maker with no basis for anything you say. Your opinion is just that, an opinion. You are the only person we are aware of that has ever seen a reduced 60' time from loss of rotational weight. You are also the only person we are aware of that can on one hand praise the laws of physics and on the other hand disprove them with completely unscientific your testing. The amount of mass required to hurt a launch is atleast twice the weight reduction of our pulleys, 8-10+ lbs.
Here's a simple test to prove what I'm saying. Take a 8" peice of string and connect it to a 1lb weight. Then take a 20" peice of string and connect it to a 1lb weight. Grasping the strings, spin the weights. You'll see that it takes a lot less force to start spining the weight attached to the 8" string and to keep that weight in motion. The point here is it's take a lot less force to spin a smaller diameter, same weight object. The same applies to your pulleys. Sure, you're removing weight, but it's a mass of weight that has a small diameter and it mounted directly to crank.
I've done the math and reducing the pulley weight to the degree that you do, will result in a realized gain of approximately 4hp in 1st gear, 2.5hp in 2nd gear, 1hp in 3rd gear, and .5hp in 4th gear. Over the span on a 1/4 mile run, the "gains" are basically worthless in a 3000lb+ car.
I am surely not only avid drag racer that has not posted an improvement in 60' time with your pulleys. I've been drag racing for over 15 years now and have drag raced domestics like Stangs and F-bodys, sport compacts, and import sedans. I've got over 500 passes under my belt and I fully understnd the physics and techniques behind drag racing. You fail to understand that in a drag race, you want some amount of moment of interia because without it, makes a car harder to launch and far more prone to bogging. It's the main reason why you don't see drag cars running lightened flywheels. Lightened assemblies like flywheels suck for drag racing, but are good for road racing because it's easier to rev match a downshift which reduces chassis movement. What applies to road race cars doesn't necessarily apply to drag cars. This is where much of your "opinion" is flawed.
Weight loss will yield an improvement in ET at any distance. Statis weight reduction needs to be significantly larger than rotational weight redcution but each will yield a corresponding drop in ET. If you dis-agree then take it up with Newton and hundreds of years of scientific data.
Your snippet about how we now say all cars use a damper is soooooo far out of context its laughable. Are you sure your not a journalist? Cause you took what you wanted out of the blog without even mentioning how we specifically rule out the need for a damper on all the sport compact vehicles we make pulleys for. Good job! I hope people finally see you as the trouble maker you really are
If you are so adamant about your claims then why don't you pay an independent lab to dis-prove us and the tens of thousands of happy UR customers that have their own dyno sheets and butt dynoes and improved tme slips.
02-23-2010, 02:58 PM
#47
I think this is both an interesting and entertaining thread!
The UR pulley was once very big on acurazine and considered the best bang for the buck mod, back when the eshift cats first came out and the only other mods were CAI and comptech catback. It is amazing how now there are so many more naysayers.
Here is my simple theory, which seems consistent with many of the comments above. Power output from the engine is unchanged (after all how could it be). However due to the lower mass of the pulley, the moment of inertia (3D integral) for the UR pulley is much lower. Since the torque for the engine hasn't changed, this allows for greater angular acceleration. This should translate into greater acceleration and power measured at the wheel.
I don't know if this is right. It has been a while since auto shop in high school and physics in college.
The UR pulley was once very big on acurazine and considered the best bang for the buck mod, back when the eshift cats first came out and the only other mods were CAI and comptech catback. It is amazing how now there are so many more naysayers.
Here is my simple theory, which seems consistent with many of the comments above. Power output from the engine is unchanged (after all how could it be). However due to the lower mass of the pulley, the moment of inertia (3D integral) for the UR pulley is much lower. Since the torque for the engine hasn't changed, this allows for greater angular acceleration. This should translate into greater acceleration and power measured at the wheel.
I don't know if this is right. It has been a while since auto shop in high school and physics in college.
02-23-2010, 03:15 PM
#48
The pulley is not about HP gain. Thus, the dyno might not reflect a gain.
The pulley is about dynamic weight loss. The dynamic weight loss is equivalent to removing 100 lbs from the car. And, a 100-lb reduction in weight is good for 1/10 reduction (one car length) in your 1/4 mile ET. It is equivalent to adding 10 HP to the car in terms of the performance improvement.
Don't worry much about stock size or undersize. The gains come from the lightweight, not from the diameter.
The pulley is about dynamic weight loss. There is a weird, inexplicable phenomenon that happens when gaining performance via weight reduction. I can not explain how or why this phenomenon occurs! But from my experiences with removing weight from my car (from small chunks to big chunks), the phenomenon is real. When gaining performance improvements derived from weight reduction, you will feel *less* g-force after the weight reduction mod. Therefore, do not use the sensation of increased g-force (aka, Butt Dyno) to evaluate the performance improvements from the UR Pulley... it won't be there.
This inexplicable phenomenon is "at play" when people say "It revs-out quicker but doesn't feel quicker". I read this comment often in regards to the pulley. I agree that it does rev quicker. However, I do not agree with the attitude in which it is stated. It is implied that "yes, it revs quicker but the car is not quicker." Now, think about this for a second. How can the engine rev quicker without the car gaining the respective MPH too ??? The transmission gearing did Not change. It is quicker.
Do Not use the Butt Dynometer to measure the performance improvements from your TL Diet (click here)
The pulley is about dynamic weight loss. The dynamic weight loss is equivalent to removing 100 lbs from the car. And, a 100-lb reduction in weight is good for 1/10 reduction (one car length) in your 1/4 mile ET. It is equivalent to adding 10 HP to the car in terms of the performance improvement.
Don't worry much about stock size or undersize. The gains come from the lightweight, not from the diameter.
The pulley is about dynamic weight loss. There is a weird, inexplicable phenomenon that happens when gaining performance via weight reduction. I can not explain how or why this phenomenon occurs! But from my experiences with removing weight from my car (from small chunks to big chunks), the phenomenon is real. When gaining performance improvements derived from weight reduction, you will feel *less* g-force after the weight reduction mod. Therefore, do not use the sensation of increased g-force (aka, Butt Dyno) to evaluate the performance improvements from the UR Pulley... it won't be there.
This inexplicable phenomenon is "at play" when people say "It revs-out quicker but doesn't feel quicker". I read this comment often in regards to the pulley. I agree that it does rev quicker. However, I do not agree with the attitude in which it is stated. It is implied that "yes, it revs quicker but the car is not quicker." Now, think about this for a second. How can the engine rev quicker without the car gaining the respective MPH too ??? The transmission gearing did Not change. It is quicker.
Do Not use the Butt Dynometer to measure the performance improvements from your TL Diet (click here)
You WILL see the gain on a dyno, otherwise there is no other mechanism to improve the car’s acceleration besides the tiny bit of weight reduction that you do get from the pulley.
I think the dynamic weight loss you are speaking of is the rotational inertial of the pulley – a lighter pulley = less rotational inertia and thus the engine can accelerate the lighter pulley quicker (faster revs) and sees less power loss because of it.
Less g-force? I don’t think so. The faster you accelerate the MORE g-forces you will feel. The engine itself may see less g’s due to its lighter weight, but this depends on how much acceleration you gain (remember F=ma, very simple).
02-23-2010, 03:18 PM
#49
I think this is both an interesting and entertaining thread!
The UR pulley was once very big on acurazine and considered the best bang for the buck mod, back when the eshift cats first came out and the only other mods were CAI and comptech catback. It is amazing how now there are so many more naysayers.
Here is my simple theory, which seems consistent with many of the comments above. Power output from the engine is unchanged (after all how could it be). However due to the lower mass of the pulley, the moment of inertia (3D integral) for the UR pulley is much lower. Since the torque for the engine hasn't changed, this allows for greater angular acceleration. This should translate into greater acceleration and power measured at the wheel.
I don't know if this is right. It has been a while since auto shop in high school and physics in college.
The UR pulley was once very big on acurazine and considered the best bang for the buck mod, back when the eshift cats first came out and the only other mods were CAI and comptech catback. It is amazing how now there are so many more naysayers.
Here is my simple theory, which seems consistent with many of the comments above. Power output from the engine is unchanged (after all how could it be). However due to the lower mass of the pulley, the moment of inertia (3D integral) for the UR pulley is much lower. Since the torque for the engine hasn't changed, this allows for greater angular acceleration. This should translate into greater acceleration and power measured at the wheel.
I don't know if this is right. It has been a while since auto shop in high school and physics in college.
thats pretty much right.
the engine will see less parasitic losses with a pulley that has a lower rotational inertia. The output of the engine stays the same, but since it takes less energy to power the accessories, this energy can now be used for the wheels. the dyno will capture this.
02-23-2010, 03:25 PM
#50
Safety Car
Perhaps I was not clear. I meant to say that there is a sensation/feel/impression of less g being experienced by your human body. I would hope that you give me some credit for understanding basic physics.
02-23-2010, 03:31 PM
#51
ha I'll give you some credit...was only staying that to be clear.
02-23-2010, 03:36 PM
#52
Safety Car
^ Nevermind. I am stupid and I don't know anything about weight reduction (static and dynamic) and the effects that it might have on the car and driver. Sorry. Please carry-on. 
02-23-2010, 04:14 PM
#54
2006 6spd
Thread Starter
iTrader: (2)
is all of yalls talk just about the under drive pulley or does it apply to both it and stock size?; i more plan to get the stock size being that i have a big amp and sub
02-23-2010, 04:42 PM
#56
the underdrive pulley gives power gains both to being lighter weight and smaller size. smaller size means there is less lorque required to spin the pulley. it also means that it will provide less power to your accessories (alternator is what you care about here if you have audio equipment) since the belt will move more slowly.
02-24-2010, 10:02 AM
#58
Burning Brakes
I'd like to add another thing regarding lightened pulleys. I've never seen evidence of a Nissan or Honda motor being wrecked by adding a lightened pulley. I ran my UR pulley for about 40K miles and 3 years and then I ran it without the UR pulley for another 1.5 years and 20K miles. The motor ran like a top. IMO, you're not going to blow the motor running one of these things. However, if you get one, make sure it has a pressed in hardened steel key way and not just aluminum. The reason being is that aluminum is soft and brittle and can deform when you tighten down the crank pulley bolt to well over 200 ft/lbs. The shrink/swell under heat of the aluminum in comparison to the hardened steel crank pulley bolt and steel crank itself can cause a problem too. The worst case scenario is the key way breaks and the pulley wobbles and seizes to the crank. When it seizes to the crank at a strange angle, it completely throws off the balance of the crank and destroys the motor. I've seen this twice now in Nissan VQ motors running lightened pulleys. Using a pulley with a hardened key way will reduce the chances of this happening.
However, IMO you're wasting your money running one of these things. Yeah, it's a relatively cheap modification, but just because it's cheap and rather easy to install, doesn't necessarily mean it's a worthwhile modification. Your $200+ would be much better spent improving your racing skills on the strip and at the auto-x.
However, IMO you're wasting your money running one of these things. Yeah, it's a relatively cheap modification, but just because it's cheap and rather easy to install, doesn't necessarily mean it's a worthwhile modification. Your $200+ would be much better spent improving your racing skills on the strip and at the auto-x.
02-25-2010, 09:24 PM
#59
Senior Moderator
How about gas mileage, wouldn't it improve slightly?
I have never heard anything bad about UD pulleys, the problem is with insufficient cooling with the addition of high hp mods. The TL doesn't have this problem. It is worth it for better throttle response and over all better performance.
I have never heard anything bad about UD pulleys, the problem is with insufficient cooling with the addition of high hp mods. The TL doesn't have this problem. It is worth it for better throttle response and over all better performance.
As far as cooling, some of the guys who ran superchargers had their engines running a little hotter than normal, the needle would be slightly above where it usually sits. However these guys had nearly ever single modification available for TL, from grounding kits to custom exhausts to custom engine work. The factory cooling is fine until you add every single bolt on + the supercharger. With the turbo it may be a different story, however I cannot attest to how the system would react.
As far as some of the other information in this thread, here are the facts:
The TL has an internally balanced crank.
The UR stock or Under-drive pulley weighs close to 5-6 pounds less than the stock pulley
The UR pulley (both under-drive and stock diameter) have not caused a single problem that has been reported on acurazine.
Also as a warning, keep it civil, next person to insult, harrass or cause trouble will get a 2 week vacation.
02-25-2010, 09:57 PM
#60
Senior Moderator
Also to add in my 
on it, the pulley works by reducing spinning mass. More torque is required to spin a heavier object, simple physics. The UR Stock Diameter Pulley does just this. It's lighter thus allowing the motor to use less power to spin the crank pulley.
Now the question is how this will affect the car, it does in many ways. First and foremost is the reduction in parasitic loss from spinning unnecessary weight. Second comes the benefit of time; the UR pulley, both stock diameter and under-drive, allow the motor to rev up slightly faster to a given point. The reason for this is the same as the first, less load on the motor.
Some simple calculus could show this, your dy/dx or a(t) of the equation of power required to spin the pulley over time would should you the slope at any given point in the RPM range. This equation would use the relationship (Related Rates) of the weight of the pulley in regards to how much power is required to spin it during a given time period. The overall graph of the UR pulley would be steeper due to the decrease in time that it takes the motor to rev.
To experience this, rev your car in neutral, it jumps up pretty quickly. Now do the same thing in drive, it'll take a bit longer as now the motor has quite a load to move. (not recommended to try this for extended periods nor bang off the rev limiter, don't break your car and blame me...)
As far as the under-drive pulley, it works by helping further remove parasitic loss from other components of the car such as Power Steering. The car is using power to spin the other components at a given RPM, lets say 1000. With the stock pulley being 7 inches in diameter, that means the belt is moving at 7pie/revolution = 21.98 inches every time the pulley spins. This times 1000 RPM means that it's moving 2198 inches a minutes at 1000RPM.
The UR pulley with it's reduced diameter (I believe it's 6.5 inches) using the same equation will come out to 20.41 inches/revolution or (13pie/2)/revolution meaning it'll be moving 2041inches per minute at 1000RPM.
In stupid terms, the belt is moving less, thus giving less power to the other components.
The question is will you feel this power using a butt dyno or see it on a dyno at a shop? The answer is yes and no. You will see, hear and feel the motor rev up faster, thus allowing you to get into the power band faster. However will you feel that surge of power you get when you go from a low HP car to a high one, no. At the dyno shop, will you see it, yes and no. Dyno's can easily have an error of 2%, so with a 200 WHP car it can be + or - 4 HP. The UR Stock diameter pulley will barely add any measurable power, may be 3-4 WHP the UR one, maybe 5-7 WHP. The real benefit is having less load to spin thus allowing you to unlock the power band faster and thus acclerate faster.
Remember, a dyno does not measure how fast your car is, it measures how much horsepower and torque you have. It can give a general idea of track times, however the only way to find them out is go to the track and try it yourself.
In my honest opinion, to spend 200+ dollars for 5 WHP isn't worth it, I'd rather spend the money elsewhere such as on an ipod or something.
on it, the pulley works by reducing spinning mass. More torque is required to spin a heavier object, simple physics. The UR Stock Diameter Pulley does just this. It's lighter thus allowing the motor to use less power to spin the crank pulley. Now the question is how this will affect the car, it does in many ways. First and foremost is the reduction in parasitic loss from spinning unnecessary weight. Second comes the benefit of time; the UR pulley, both stock diameter and under-drive, allow the motor to rev up slightly faster to a given point. The reason for this is the same as the first, less load on the motor.
Some simple calculus could show this, your dy/dx or a(t) of the equation of power required to spin the pulley over time would should you the slope at any given point in the RPM range. This equation would use the relationship (Related Rates) of the weight of the pulley in regards to how much power is required to spin it during a given time period. The overall graph of the UR pulley would be steeper due to the decrease in time that it takes the motor to rev.
To experience this, rev your car in neutral, it jumps up pretty quickly. Now do the same thing in drive, it'll take a bit longer as now the motor has quite a load to move. (not recommended to try this for extended periods nor bang off the rev limiter, don't break your car and blame me...)
As far as the under-drive pulley, it works by helping further remove parasitic loss from other components of the car such as Power Steering. The car is using power to spin the other components at a given RPM, lets say 1000. With the stock pulley being 7 inches in diameter, that means the belt is moving at 7pie/revolution = 21.98 inches every time the pulley spins. This times 1000 RPM means that it's moving 2198 inches a minutes at 1000RPM.
The UR pulley with it's reduced diameter (I believe it's 6.5 inches) using the same equation will come out to 20.41 inches/revolution or (13pie/2)/revolution meaning it'll be moving 2041inches per minute at 1000RPM.
In stupid terms, the belt is moving less, thus giving less power to the other components.
The question is will you feel this power using a butt dyno or see it on a dyno at a shop? The answer is yes and no. You will see, hear and feel the motor rev up faster, thus allowing you to get into the power band faster. However will you feel that surge of power you get when you go from a low HP car to a high one, no. At the dyno shop, will you see it, yes and no. Dyno's can easily have an error of 2%, so with a 200 WHP car it can be + or - 4 HP. The UR Stock diameter pulley will barely add any measurable power, may be 3-4 WHP the UR one, maybe 5-7 WHP. The real benefit is having less load to spin thus allowing you to unlock the power band faster and thus acclerate faster.
Remember, a dyno does not measure how fast your car is, it measures how much horsepower and torque you have. It can give a general idea of track times, however the only way to find them out is go to the track and try it yourself.
In my honest opinion, to spend 200+ dollars for 5 WHP isn't worth it, I'd rather spend the money elsewhere such as on an ipod or something.
03-13-2010, 08:54 PM
#61
2006 6spd
Thread Starter
iTrader: (2)
i finnaly installed it today and it was done by the all mighty ME!!! i was reall scared to do it myself but said what the H#*L and want for it!!! took advantage of the free loan a tool service at my local auto zone barrowing a torque wrench and a breaker bar; purchased a 1/2 drive 20in socket extension and a 19mm impact socket only to return when i was done...didnt take too long and wasnt very hard at all... theres a thread in here some where with full instructions but not sure where or how to ponst a link to it just typed in tension pulley on google clicked on a pic that showed the powersteering bottle in it... think it was installation for a TSX but basicly the same thing... if your a do it yourselfer id say go for it!!! Just want to say thank you to ACURAZINE.COM and everyones support!!!
03-14-2010, 04:33 AM
#63
I'd like to add another thing regarding lightened pulleys. I've never seen evidence of a Nissan or Honda motor being wrecked by adding a lightened pulley. I ran my UR pulley for about 40K miles and 3 years and then I ran it without the UR pulley for another 1.5 years and 20K miles. The motor ran like a top. IMO, you're not going to blow the motor running one of these things. However, if you get one, make sure it has a pressed in hardened steel key way and not just aluminum. The reason being is that aluminum is soft and brittle and can deform when you tighten down the crank pulley bolt to well over 200 ft/lbs. The shrink/swell under heat of the aluminum in comparison to the hardened steel crank pulley bolt and steel crank itself can cause a problem too. The worst case scenario is the key way breaks and the pulley wobbles and seizes to the crank. When it seizes to the crank at a strange angle, it completely throws off the balance of the crank and destroys the motor. I've seen this twice now in Nissan VQ motors running lightened pulleys. Using a pulley with a hardened key way will reduce the chances of this happening.
However, IMO you're wasting your money running one of these things. Yeah, it's a relatively cheap modification, but just because it's cheap and rather easy to install, doesn't necessarily mean it's a worthwhile modification. Your $200+ would be much better spent improving your racing skills on the strip and at the auto-x.
However, IMO you're wasting your money running one of these things. Yeah, it's a relatively cheap modification, but just because it's cheap and rather easy to install, doesn't necessarily mean it's a worthwhile modification. Your $200+ would be much better spent improving your racing skills on the strip and at the auto-x.
I understand your theory and your opinion but you can't dodge hundreds of people on AZ personal experiences. What I don't understand is why you have so much negativity toward it without true experience. I've talked to my team mechanic regarding the pulley and he says it is legit (Kenny Tran renowned tuner/racer in Dallas TX) and tons of other people. Also, it's nearly impossible to calculate precise Performance increase of a pulley, perhaps, the pulley itself but not the pulley on the car. So your theory it makes 2 hp avg per gear is outright stupid. I don't mind you making opinions but it seems like you have it out for the pulley with 0 evidence but your "physics" I've taken calculus based physics and labs for 3 years n it certaintly applies but come on now, 6-10 hp freed and proven by our TL, not G35 or 350z, for $200. You'd be stupid not to buy it if you're serious abou modding a TL
03-14-2010, 04:41 AM
#64
And once again the pulley doesn't increase HP
necessarily buT it frees up weight equivalent, such as innacurate said, 100lb. You may not feel it like any other mods but it's there. Any 3G TL veteran would agree. Dunno why anyone is scared or thinks this mod is not good. Of course with improper installation or cheap aftermarket pullies with any car could have problems but the UR pulley that we have for our cars has been working flawless with nearly 0 complaints and thousands of satisfied users. At the end of the day, screw physics, because that is all that matters
necessarily buT it frees up weight equivalent, such as innacurate said, 100lb. You may not feel it like any other mods but it's there. Any 3G TL veteran would agree. Dunno why anyone is scared or thinks this mod is not good. Of course with improper installation or cheap aftermarket pullies with any car could have problems but the UR pulley that we have for our cars has been working flawless with nearly 0 complaints and thousands of satisfied users. At the end of the day, screw physics, because that is all that matters
03-14-2010, 04:47 AM
#65
Also to add in my on it, the pulley works by reducing spinning mass. More torque is required to spin a heavier object, simple physics. The UR Stock Diameter Pulley does just this. It's lighter thus allowing the motor to use less power to spin the crank pulley.
Now the question is how this will affect the car, it does in many ways. First and foremost is the reduction in parasitic loss from spinning unnecessary weight. Second comes the benefit of time; the UR pulley, both stock diameter and under-drive, allow the motor to rev up slightly faster to a given point. The reason for this is the same as the first, less load on the motor.
Some simple calculus could show this, your dy/dx or a(t) of the equation of power required to spin the pulley over time would should you the slope at any given point in the RPM range. This equation would use the relationship (Related Rates) of the weight of the pulley in regards to how much power is required to spin it during a given time period. The overall graph of the UR pulley would be steeper due to the decrease in time that it takes the motor to rev.
To experience this, rev your car in neutral, it jumps up pretty quickly. Now do the same thing in drive, it'll take a bit longer as now the motor has quite a load to move. (not recommended to try this for extended periods nor bang off the rev limiter, don't break your car and blame me...)
As far as the under-drive pulley, it works by helping further remove parasitic loss from other components of the car such as Power Steering. The car is using power to spin the other components at a given RPM, lets say 1000. With the stock pulley being 7 inches in diameter, that means the belt is moving at 7pie/revolution = 21.98 inches every time the pulley spins. This times 1000 RPM means that it's moving 2198 inches a minutes at 1000RPM.
The UR pulley with it's reduced diameter (I believe it's 6.5 inches) using the same equation will come out to 20.41 inches/revolution or (13pie/2)/revolution meaning it'll be moving 2041inches per minute at 1000RPM.
In stupid terms, the belt is moving less, thus giving less power to the other components.
The question is will you feel this power using a butt dyno or see it on a dyno at a shop? The answer is yes and no. You will see, hear and feel the motor rev up faster, thus allowing you to get into the power band faster. However will you feel that surge of power you get when you go from a low HP car to a high one, no. At the dyno shop, will you see it, yes and no. Dyno's can easily have an error of 2%, so with a 200 WHP car it can be + or - 4 HP. The UR Stock diameter pulley will barely add any measurable power, may be 3-4 WHP the UR one, maybe 5-7 WHP. The real benefit is having less load to spin thus allowing you to unlock the power band faster and thus acclerate faster.
Remember, a dyno does not measure how fast your car is, it measures how much horsepower and torque you have. It can give a general idea of track times, however the only way to find them out is go to the track and try it yourself.
In my honest opinion, to spend 200+ dollars for 5 WHP isn't worth it, I'd rather spend the money elsewhere such as on an ipod or something.
on it, the pulley works by reducing spinning mass. More torque is required to spin a heavier object, simple physics. The UR Stock Diameter Pulley does just this. It's lighter thus allowing the motor to use less power to spin the crank pulley. Now the question is how this will affect the car, it does in many ways. First and foremost is the reduction in parasitic loss from spinning unnecessary weight. Second comes the benefit of time; the UR pulley, both stock diameter and under-drive, allow the motor to rev up slightly faster to a given point. The reason for this is the same as the first, less load on the motor.
Some simple calculus could show this, your dy/dx or a(t) of the equation of power required to spin the pulley over time would should you the slope at any given point in the RPM range. This equation would use the relationship (Related Rates) of the weight of the pulley in regards to how much power is required to spin it during a given time period. The overall graph of the UR pulley would be steeper due to the decrease in time that it takes the motor to rev.
To experience this, rev your car in neutral, it jumps up pretty quickly. Now do the same thing in drive, it'll take a bit longer as now the motor has quite a load to move. (not recommended to try this for extended periods nor bang off the rev limiter, don't break your car and blame me...)
As far as the under-drive pulley, it works by helping further remove parasitic loss from other components of the car such as Power Steering. The car is using power to spin the other components at a given RPM, lets say 1000. With the stock pulley being 7 inches in diameter, that means the belt is moving at 7pie/revolution = 21.98 inches every time the pulley spins. This times 1000 RPM means that it's moving 2198 inches a minutes at 1000RPM.
The UR pulley with it's reduced diameter (I believe it's 6.5 inches) using the same equation will come out to 20.41 inches/revolution or (13pie/2)/revolution meaning it'll be moving 2041inches per minute at 1000RPM.
In stupid terms, the belt is moving less, thus giving less power to the other components.
The question is will you feel this power using a butt dyno or see it on a dyno at a shop? The answer is yes and no. You will see, hear and feel the motor rev up faster, thus allowing you to get into the power band faster. However will you feel that surge of power you get when you go from a low HP car to a high one, no. At the dyno shop, will you see it, yes and no. Dyno's can easily have an error of 2%, so with a 200 WHP car it can be + or - 4 HP. The UR Stock diameter pulley will barely add any measurable power, may be 3-4 WHP the UR one, maybe 5-7 WHP. The real benefit is having less load to spin thus allowing you to unlock the power band faster and thus acclerate faster.
Remember, a dyno does not measure how fast your car is, it measures how much horsepower and torque you have. It can give a general idea of track times, however the only way to find them out is go to the track and try it yourself.
In my honest opinion, to spend 200+ dollars for 5 WHP isn't worth it, I'd rather spend the money elsewhere such as on an ipod or something.
Just say it made 5 WHP and not the 6-10 WHP I originally said, that is still a whole lot of HP gained for the money.$40 per WHP is not bad. Supercharger is what $4k+? We'll just say it gains 35 WHP without boost, you're talking about over $100 per WHP. That is why the J-pipe and UR Pulley are great mods. Best Price to HP ratio of all performance modifications we have.
Last edited by TheChamp531; 03-14-2010 at 04:51 AM.
03-14-2010, 12:12 PM
#66
2006 6spd
Thread Starter
iTrader: (2)
well like any mod you dont notice a significant difference unless your going turbo/supercharger just like CAI you know it there but not nessicarrily a drastic change; as for my thoughts im happy with it actually bought it from thechamp brand new for a good price so any mod thats gonna help improve my BABY im all in! As for significant gains and drastic change NO but after reading everyones post to this thread i have a better idea of what its doing... My happyness would i guess be compaired to maybe my CAI you know something has to be there and thats all i need because im assuming in would of never been thought of or invented in the first place...if any thing alittle smoother and slightly better throttle response i have th stock size but im assuming the underdrive would be just a little better based on reviews but i have a big sub and amp... again the OEM pulley weighs a ton compaired to the UR...Hope this helps
Thread
Thread Starter
Forum
Replies
Last Post
rp_guy
Member Cars for Sale
9
07-16-2017 07:33 AM
