Does a light weight pulley actually help increase hp?
#42
Originally Posted by engifineer
Originally Posted by zer0
http://clubstlscion.com/forum/forum_posts.asp?TID=2835&PN=1&TPN=3
If someone can come out and dispell the laws of motion that we use everyday to calculate everything from automotive physics to the motions of the planets, then I will be all ears. And if one person can take a good number of 1/4 mile runs with a stock pulley, swap to a lighter one and take a good number more and show me a significantly (respectively) lower time, I may look closer. Will reducing mass help? Sure, since you are making acceleration of the engine easier, but I can bet that you will find that the real performance increase you measure on the track (especially with such a small change in rotational mass on a small diameter object) will not add up to a 15whp or so gain.
Anyway, as usual we are all beating this to death, and the people that believe anything a shop with a dyno and a part to sell will believe that, the people that want to believe one way or the other will believe the same and those of us that are a little more skeptical after seeing mod after mod produce little or none of what is promised (not suprisingly when the physics says it wont) will believe what we do. So I guess we can at least agree on that point and go to bed now.... :D
So I reckon, Lightweight flywheels are pointless, lightweight crank pulley is pointless, and running lighter wheels on a track is pointless. Yet they all contribute to faster acceleration, and faster lap times...
#43
I didnt say they were worthless.. were did you say that? Now, the effect of a lightweight pulley verses the risks.. IMO is completely worthless. I never said (which was very clear in my post) that the two did not help in some way, what I said was that they do not create or free up hp. Any high school or early college physics textbook can show you that.
I thought I was pretty clear on those points. I dont know how more clearly I can put it really. Do what you like. Apparently the "Tuner" shops trying to sell a pulley know more than ATI or Dinan, or even Newton for that matter...
I thought I was pretty clear on those points. I dont know how more clearly I can put it really. Do what you like. Apparently the "Tuner" shops trying to sell a pulley know more than ATI or Dinan, or even Newton for that matter...
#45
That is a good question. Anytime a dyno result totally contradicts the simplest of physics.. I would question the dyno operator. I hate to start a war, but fact is fact. If you understood the basic physics involved, you would agree. Reducing rotating inertia ONLY effects accelleration or decelleration of the object (pulley in the example), not hp to the wheels. That is cut and dry physics, which has been tested a bit more scientifically than a crank pulley on a shops dyno.. who is trying to sell crank pullies. There are a lot of ways to read "gains" on a dyno. Again, I havent seen one set of before and after times that reflect those gains.. cause they arent there. Does it help? Yes. But no NEARLY as much as is advertised, because it only effects accelerating the crank.. add in gearing and the large difference in acclerations between the crank and wheels and the effects over 1/4 mile are minimal.
Hey, if you like your pulley, that is great for you. But I am not going to come back and say mr newton and his friends had it all wrong (not to mention any big, long standing builder out there) because a shop that builds pulleys says so. A CAI gains you 10whp too right?
A weighted wheel works as a flywheel. It STORES kinetic energy. That is its purpose. Meaning any power wasted to start it moving is restored to the system later (by keeping it turning). Conservation of momentum is great that way. The energy is NOT wasted.
As much as I like discussing cars and physics.. this will never go anywhere. Again, you can pick up a physics textbook (upper high school or early college level) and read up on the principles and it makes complete sense. That is all I can offer at this point, and should be all that is needed. I dont want to start any discontent between any of us. I can agree to disagree and call it good, but I have no reason to change my mind based upon the facts out there.
Hey, if you like your pulley, that is great for you. But I am not going to come back and say mr newton and his friends had it all wrong (not to mention any big, long standing builder out there) because a shop that builds pulleys says so. A CAI gains you 10whp too right?
A weighted wheel works as a flywheel. It STORES kinetic energy. That is its purpose. Meaning any power wasted to start it moving is restored to the system later (by keeping it turning). Conservation of momentum is great that way. The energy is NOT wasted.
As much as I like discussing cars and physics.. this will never go anywhere. Again, you can pick up a physics textbook (upper high school or early college level) and read up on the principles and it makes complete sense. That is all I can offer at this point, and should be all that is needed. I dont want to start any discontent between any of us. I can agree to disagree and call it good, but I have no reason to change my mind based upon the facts out there.
#46
Having lighter masses to make spin around, especially with the A/C unit, will help your engine take less power away from the wheels to power things like the A/C, or recharge the battery. Whether you have a 50lb rotating mass, or a 2lb rotating mass, if they have the same diameter, it takes about the same energy to keep it spinning at the same speed. Granted, with the same power input, the heavier rotating mass with spin longer, but the same energy is required to keep them moving at the same speed.
Think about a big truck. They burn more gas shoving their huge mass to keep a constant speed, than a little car does, and no, it's not just because there is more drag. With the big truck, it's harder to stop, and takes a freaking long time to get going. The same principle has to do with the pulleys. Lighter takes less energy to get going, and less to stop, thus increasing acceleration of the engine, which can result in higher acceleration times.
Now, I fully agree with engineer dude about the fact that replacing 3 pulleys will not get you 15whp, but I don't think anyone was claiming that. What I have seen regularly from guys is about a 5whp gain, max, on average, with replacing all 3 pulleys using the NST pulleys.
Putting on a lighter fly-wheel, I personally don't think is a good idea if you are doing any type of race where launch is important. Yes, you could shave off a few pounds from your car, but you want that rotating hunk to help your engine launch faster.
Think about a big truck. They burn more gas shoving their huge mass to keep a constant speed, than a little car does, and no, it's not just because there is more drag. With the big truck, it's harder to stop, and takes a freaking long time to get going. The same principle has to do with the pulleys. Lighter takes less energy to get going, and less to stop, thus increasing acceleration of the engine, which can result in higher acceleration times.
Now, I fully agree with engineer dude about the fact that replacing 3 pulleys will not get you 15whp, but I don't think anyone was claiming that. What I have seen regularly from guys is about a 5whp gain, max, on average, with replacing all 3 pulleys using the NST pulleys.
Putting on a lighter fly-wheel, I personally don't think is a good idea if you are doing any type of race where launch is important. Yes, you could shave off a few pounds from your car, but you want that rotating hunk to help your engine launch faster.
#48
Lightweight crank pulleys do not increase HP at all, they do free up parasitic drag caused by heavier pulley’s thus allowing higher HP numbers seen on a dyno. It will depend on the weight of the OEM pulley vs the lightweight pulley of how much power difference you will notice. Everyone will say it won’t harm your engine, well it depends on what your plans are with your car. The pulleys will not make immediate harm to your engine however after prolonged use you will notice a significant increase of strain to the bearings. Take two OEM engines run one 100,000 miles without a pulley and with a pulley then compare the bearing differences you will notice how poor the bearings on the engine with a lightweight pulley vs a damper even just a thin strip of rubber is still a damper. I am not saying your engine will go out but you do increase the risk once you have it for prolonged use. Prolonged use is not a year and 30K I am talking about several years and over 100K – 150K you will notice the added stress to the bearings.
#49
Got my OBX pullies installed yesterday (Crank, Water Pump, Alternator) and I can tell the difference in acceleration due to less rotational mass from the OEM pullies. Car also idles a little more smoothly. The true test will be in a couple weeks when I compete in Import Wars at Great Lakes Dragway....then I'll have the #'s to see what the improvements are.
#50
Competed in a Drag Racing event this weekend and my first two passes were against a manual tC that was fairly similar to my set up and I was able to take the win light both times and I'm auto. I have the OBX crank, water pump, alternator pulley's and I'm sure that played a factor in why I was able to pull away from him from start to finish. If you don't believe me I have the time slips to prove it. Definitely liking the quicker acceleration response with the pulley's....There's a noticeable difference that my auto tC is shifting a lot quicker than before and really pulls strong on the big end of the track.
#51
Competed in a Drag Racing event this weekend and my first two passes were against a manual tC that was fairly similar to my set up and I was able to take the win light both times and I'm auto. I have the OBX crank, water pump, alternator pulley's and I'm sure that played a factor in why I was able to pull away from him from start to finish. If you don't believe me I have the time slips to prove it. Definitely liking the quicker acceleration response with the pulley's....There's a noticeable difference that my auto tC is shifting a lot quicker than before and really pulls strong on the big end of the track.
#52
Lol, I wasn't saying that because I had pulley's it makes me faster than a manual tC, I'm just saying that those pulley's helped. Saying I'm faster than a Manual tC just because I have pulley's is just plain silly. Lol, and I always have proof to back up what I say, check out my thread (Woodard Racing N/A build) time slips are posted! I'm not one of these guys that lie about what their car performs. Time slip 1 and 2 are against the manual tC and I even make note that the first slip #'s were off because the guy missed 2nd. Before you say something about that this dude was no rookie! His second car he was racing was a twin turbo manual supra that was running 10's consistantly so I think he knows what he's doing.
Last edited by BadDudeTC3; 05-25-2011 at 03:52 AM.
#53
Lol, I wasn't saying that because I had pulley's it makes me faster than a manual tC, I'm just saying that those pulley's helped. Saying I'm faster than a Manual tC just because I have pulley's is just plain silly. Lol, and I always have proof to back up what I say, check out my thread (Woodard Racing N/A build) time slips are posted! I'm not one of these guys that lie about what their car performs. Time slip 1 and 2 are against the manual tC and I even make note that the first was #'s are so different because the guy missed 2nd. Before you say something about that this dude was no rookie! His second car he was racing was a twin turbo supra running 10's so I think he knows what he's doing.
#54
I know these original posts are old, but whatever you do, don't buy the pulleys from NST, or buy with caution. I purchased the underdrive pulley kit 5 months ago, and I still don't have the wp pulley. Plus, they never answer their phone and rarely respond to my emails.
#55
We’ve all heard it before, “Do lightweight aluminum pulleys free horsepower? Do they make your car faster? Are they really worth it?” At NonStopTuning we’ve been designing and testing pulley kits of various types for over a decade, and have posted our results on various outlets. We’ve decided to consolidate these results into one post, with several links, for your review: https://nonstoptuningusa.com/dynos/
Best of luck with all your projects everyone!
#56
#60
Why are NST pulleys better?
● more color options
○ red, blue, purple, gold, black, green
● weight reduction
○ 70 to 75% vs OEM
● anodizing makes aluminum stronger
○ most other brands don't anodize
● oil sleeves on crank pulleys
○ most other brands don't add sleeves
● proper crank pulley timing marks
○ in the same location as oem pulleys
www.NonStopTuning.com