I always wondered about the random installs that some people do to their Tc's without any regard to safety/functionality. One of those random things happened to be a lightweight crank pulley, I was very skeptical about this because it
did not incorporate a rubber damper in the pulley.I was told by a very experienced Japanese car tech who once said "if the Japanese put the part on the car, it is there for a reason because they usually think of everything in terms of engineering."
So here I am now with a different outlook on after market lightweight crank pulleys and this is why.. ---------------> http://www.unorthodoxracing.com/

Whose website states: "Is my crank pulley a harmonic/torsional/vibration damper or a harmonic balancer?"

People are getting their crank pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term used loosely in the automotive industry. Technically, this type of device does not exist.
The "balancer" part comes from engines that are externally balanced and have a counterweight cast into the damper, hence the merging of the two terms. None of the applications we offer use a counterweight as part of the pulley,
as these engines are all internally balanced.

The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that makes them look similar to a harmonic damper. The elastomer in the OEM pulley serves as an isolator, which is there to suppress natural vibration and noise from the engine itself, the A/C compressor, P/S pump, and alternator. This is what the manufacturers call NVH (Noise Vibration & Harshness) when referring to noticeable noise and vibration in the passenger compartment. It is important to note in these applications, the elastomer is inadequate in size and durability to act as an effective torsional damper. If you look at the pulleys on some imports there is no rubber to be found at all. We have samples of these, mostly from Acura/Honda, the Nissan Altima, 1.8L Eclipse, 2.3L Fords, Chrysler 2.2L's, and 1.8L VW's, to mention a few. This is not to say with our pulleys you will hear a ton of noise or feel more vibration from your engine compartment. Most owners who have installed our pulleys notice the engine actually feels smoother. This is result of replacing the heavy crank pulley with our crank pulley. NVH is variable and unique to every car. NVH will increase with the installation of an aftermarket intake and/or exhaust, for example. Think of OEM intake systems in newer cars, they use baffles and resonators in the intake to quiet all the intake noise. Aftermarket intakes eliminate these resonators and create dramatic increases in engine noise from the throttle opening and closing. So to most tuners, certain types of NVH can make the driving experience more enjoyable.

The purpose of a traditional harmonic damper is to protect against crank failure from torsional movement. This is not necessary in most modern engines because of the many advances in engine design and materials.
Factors such as stroke length, displacement, inline, V configurations, piston dwell time, piston pin off-set, power output, etc., do determine when and how these harmonics and torsional movements occur.

Again, there is a lot of internet hearsay about crank pulleys. When engine problems occur, too often people are quick to blame the pulley first, rather than taking the time to look logically into why there was a problem.
We hope that after reading this you will understand the crank pulleys better.

* I will not always believe everything I read, but I don't have any doubts about this anymore.

____

 

When I read that article, it mentions the elastomer that is built into crank pulleys on cars such as ours. Considering the source (a website that sells lightweight crank pulleys), I'd say that "It is important to note in these applications, the elastomer is inadequate in size and durability to act as an effective torsional damper" is a blanket statement. They don't have evidence to back that up, especially not for every application. Going along with what your experienced tech friend said, why would manufacturers put inadequate damping systems in their pullies if it's common knowledge enough to be on the unorthodoxracing website? Additionally, the claim that the car feels smoother is not explained either, just said to be a "result of replacing the heavy crank pulley with our crank pulley." The parallels drawn between NVH in the crank with airboxes and exhausts is also unrelated, as those forms of NVH do not have such a direct effect on the engine itself.

Nothing against you, but I don't think this is even close to an end-all article. If you look closely, it's written by a biased source, presents general statements with little to no evidence in support of the claims, and uses parallels that are not the same.

 

It does make sense though... with all the amazing advancements in mechanical engineering I cannot even begin to conceive the idea that a little rubber ring is really all that would stand between total engine structural failure . Just wouldn't make a lick of sense to me.

 

First, a damper and balancer are two different things. Funny that unorthadox either is too uneducated to know this, or just decided to confuse the un-knowing with the harmonic balancer crap, which is not applicable to this conversation. They mention it so as to confuse people regarding which is which and what they both do (they are different things) Our engines are internally balanced, so of course they have no harmonic balancer. But that does abosolutely nothing to affect resonance, or "ringing" to set up in the crank.

Second, a company selling crap mods that take none of the design engineering that toyota spent time and money to incorporate will say anything to sell a pulley.

Third, I have yet to see one company selling these, defend them with a shred of physics knowledge.

Fourth, some very minute design changes would have kept the tacoma narrows bridge from falling into the river. Same concept. So that "little peice of rubber" is pretty important for the long life of your engine.

It is called torsional vibration, and can destroy anything from an engine, to a turbine to a full sized bridge, without proper damping.

People all have thier own opinions, but they should at least read a little physics before trying to defend something.

Been discussed a million times. And I will take physics and REAL engine builders like dinan and ati over these little parts sellers anyday. You can read what those three say all over the web.

 

You were "sold" by the company making the part, who obviously knows nothing about the part they are selling or is chaning the subject to confuse you, as I explained above. If you want more impartial links, look through this thread:

http://www.yoursciontc.com/forums/in...pic=14934&st=0

It has links from Dinan (you know.. a real shop, building world class performance), ATI (who was asked by a lot of people to build an undampened pulley for the tC. Their response was that they would build one with MORE dampening to handle higher hp builds) and Toyota.. who we all know

We had NST post some info.. but of course danced all around the physics and actual use of having a TORSIONAL damper just like unorthodox is doing. And their descriptions and explanations had little, if any physics to back it up. Only more tuner shop bs.

If McDonalds told you that 600 calorie hamburgers with 500 calorie orders of fries was good for you.. would you believe them?

Not trying to bash you for what you posted, but bashing the companies that fed you this.

Just be sure to read ALL the info, from a source not trying to sell a part.

They probably also say it "frees up hp" as well.... let me know if you want me to quote actual physics data and laws to throw that in the trash.
A flywheel (which the pulley acts as) STORES KINETIC ENERGY, so no hp is lost regardless of weight, it is just used differently/at different moments.

__________________

 

how about reading this post be4 you buy...it might change ur mind
http://www.yoursciontc.com/forums/in...opic=6923&st=0

 

so wait does the NST pulley really put out the hp it claims to put out?

 

None of them do. It is against all laws of physics for a lighter flywheel to increase or "free up" hp. They either dyno them on an inertial dyno, which is fooled by changes in rotational mass, or they simply skew thier dyno numbers.

Again, a uniform disc acts like a flywheel, which stores kinetic energy. This is why every increase in revving is accompanied by a decrease in inertia, meaning the engine is just as easilly slowed back down due to the lighter pulley not carrying as much momentum.

A lightweight pulley or flywheel does nothing but make the engine rev quicker, it does absolutely nothing to increase hp to the wheels.

For that part, you dont need company links, you can simply look up and read up on the laws of physics governing moments of inertia, rotating masses, etc.

 

let me tell you something, i've had the ur pulley for quite some time. i go to the drag strip every monday and wednesday.also i go to racing nights on saturday, wich it means that i step on my car as if it was stolen and i havnt had any problems with it so far. you can really feel the diff.

 

You can feel the difference by sticking your hand in a blender too. First it's there, then it's not! What a bargain!

If the pro-undampened crank pulley folks want to defend their claim, try navigating beyond the "gut feeling" bull____, because none of it means anything.

 

I have two questions then:

1. Are the alternator and water-pump pullies safe?

2. Why is it that any of the above mentioned companies that DO make safe pullies have yet to for us? What's taking them so long?

 

Yep... I have asked and asked and asked for real before and after numbers (a group of runs before and a group after) and have had ONE person give me some real data... that data showed a .1 sec gain (WOW.. and that could be variation in driving) once and an INCREASE in time the other couple of times. That tells me that any difference he had was only due to driver variation. Due to finding NO usable gain and reading stories from people having issues, plus taking time to read all the data an principles, he switched back to stock. It WILL make the car rev quicker.. that is about it, especially with something as minimal in diameter and weight as the crank pulley. Seat of the pants means jack.. people also say they "feel a good gain" with a CAI, which is BS... it is called Butt Dyno fooled by loud noises

And saying you ran it on the track some and had no problems shows you are still not reading the info we linked. The vibrations dampened by a harmonic damper affect long term engine life.
There are instances (the Supra guys found this out) of it causing damage fairly soon, but the most common issue is premature bearing failure, oil pump failure, etc.
The even better part is that in those long term cases it is virtually impossible to attribute it to the pulley to the point you can sue the manufacturer, which is why they are so willing to back their product.

Again, the info is all posted. You have the gut feeling crap and the 100% verifiable info from the links we have posted and the physics books. Everyone can have their own take on it,
but please, for the love of god, actually read the info posted before arguing. Like a couple of posts up, the point is missed in virtually every argument.

SF2k4, I know of no company making a safe one for the crank. ATI is a very good company for this. They were approached by people from YStC and their response was to build a pulley with MORE damping
since it would be in a high performance application (built motors.. boosted, etc). Last I heard, they wont build an undampened pulley. They even build dampened units for race applications.


__________________

 

I retract my previous statement...

 

Yea, I mean why aren't they making dampened ones? What's the hold up?

 

ok so in your opinion: im going the nitrous route, looking into 300whp(in total), are the NST pulleys worth my time and money....

cai no gains??....but that has been dynoed, and what not please explain, im looking into the injen intake...

 

There are gains with an intake, however, they're only peak gains, which means next to nothing when the number is less than like 20.

If you gain 10 peak horsepower, the actual umph is averaged throughout the entire powerband. Do you think you'll really feel that 10 horsepower (even if it's 10) when it's averaged through 6200 RPMS?

Na. Not at all. The sound will make you think you feel it, and that's it.


Pullies are worth no one's time or money unless it's for a Supercharged application, where there is an actual effect.

 

I have been around and worked in a machine shop all my life and I changed out my pulley just recently. When I removed the pulley i saw the rubber ring and knowing that castings ( the pulley is a casting except for the ribs that hold the belt in place) have many imperfections in them, led me to believe the rubber ring on the pulley allows the belt and pulley to float freely with the inconsistancies in the pulley's casting. I called ZPI before installing the pulley and asked them what the pulleys tolerences were and they said that it was much closer the the stock pulley. This would be a result of machining the majority of the pulley (every step that needs to be precise without removeing the part from the machine) resulting in a more precision part and near perfectly balanced pulley. So I have reason to believe that the pulley will never cause damage to the crank, bearings, seals, etc. I hope this was helpful to everyone. PM me if you have any questions.

 

so are the gains claimed NST peak gains as well?....how about turbocharged applications?

 

The fact that the aftermarket pulleys are perfectly balanced is not the issue. The stock pulley does not balance the engine. The rubber DAMPENS the harmonics of the motor. The pulley does not gain you horsepower. That is like saying my light weight wheels gave me horsepower..........no they didn't. The way they state the claim is not true.

 

all pullies will actually do if you are N/A is let you rev up and down easier, nothing more nothing less, might let the engine spin a little easier, but its all a perception of the mind that makes you think it helps, just because you spent 130 on it.
you feel guilty for spending money that could have been used elsewhere.

Unless you are supercharged the pulley will not help...

The engine is internally balanced so balancing has almost nothing to do with the problem as much as removing the dampener.

removing the dampener like stated above for you to lazy to read above posts, WILL CAUSE PREMATURE FAILURE OF EITHER THE CAM CHAIN OR THE OIL PUMP, maybe even more, complicated problems.

try taking a wheel and using no tire on it, it does not work how it is supposed to, and imagine us having wooden tires like back in the day, do you think that the suspension will last as long as it lasts today.

My point is, Toyota is a very respectable company, that puts thousands of dollars into R&D to perfect their products, for best use over a long period of time, sure the pulley might feel a lil better on the butt dyno now, but in the long run your engine will not last as long