EricL

If your are not interested in any other pulleys than the UR pulleys and are happy and don't want to be bothered, stop reading now. I am very impressed with the results that mattg got today, and would love to see a "firm" answer" come from UR (some methods to determine what's going on are possible) AND if they are not going to put out the "equivalent" vibration studies that other pulley makers do, perhaps someone else would be willing to make some very light pulleys with advanced damping that could actually make MORE power with MORE reliability. If UR thinks they have such a product AS IS -- I'm very interested in seeing the graphs and data that fluidampr supplies!

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http://www.fluidampr.com/torsional_vibration.html (Fluidampr)


Measurement of vibration link: http://www.fluidampr.com/testresults.html (stock vs the lightweight AND DAMPED pulleys) (UR are not damped)

This site has info on how these guys actually measure the amount of damping of their performance dampers vs. the competition (sorry, no UR comparisons). However, it is possible for someone to make a damper with some viscous liquid in it (or elastomeric material) that can damp BETTER than stock if someone will spend the time to do all of the harmonic analysis. The site explains how THEY do it and with what equipment!

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Warning: NEGATIVE INPUT HERE

http://www.pacarsearch.com/stealth/udp.htm (The Stealth Guy has probably seen all the flames he will ever need)

And a letter -- he had them and mounted them on his engine (a Stealth). He got a chance to find his bearing wearing out and when the engine was mounted to via solid engine mounts, the UR pulleys were shaking him to death...

http://www.pacarsearch.com/stealth/buschur.htm


"Letter from Dave Buschur to Talon Digest Sept. 1998

Hello, I am not starting a debate again. As a matter of fact, if you have some questions send me a private e-mail. I do have some facts though. First let me say, yes, I have been running an Unorthodox underdrive pulley for about a year. I have had no problems that I can blame on the pulley, they are nice and they are cheap. If they do pick up 10hp like Turbo Magazine says they do then they are a bargain. Now to my point. As alot of you know I have been working with a company to have some custom dampers done with the underdrive built into them. They are finally done and I have done the final testing. We have had the first unit on and off the AWD a few times to get results back and the final settings have been made. After looking at the unit and getting the feedback from the shop that is building the units for us there is ABSOLUTELY NO doubt that these cars, just as we thought, have to have the damper on them. I have had some unusual bearing wear for the last year or so. The more I learn about dampers the more I understand that the problem was 99% related to the fact I have not been running one. We did end up keeping the underdrive unit in the damper too. So there is less drag and we get a superior damper compared to the stock unit. Now, everyone that has ever bought a performance part thinks it works, why? Well you just spent your hard earned money on it. I have done the same thing in the past I am sure. I am very skeptical nowadays. Well I took the damper off the AWD Sunday and put it on the RWD. Since it is the only one I have so far I wanted to swap it. The difference? Holy $h!t. The RWD engine is mounted to solid aluminum plates which are bolted directly to the frame of the car. The car vibrates so hard it goes up your spine, it also vibrates enough to readjust the rearview mirror just revving the engine. I cannot believe it but this is all but gone. I mean you can still feel the engine has some vibration, it has to mounted this way, but the majority of it is gone. I am going to be really curious next time we pull this engine down to see what the bearing look like. I have 10 more being shipped to me ASAP, they are built, the shop and I are just working out pricing. The first 7 are sold. This is the list of the guys first names (for privacy), you guys will know who you are, if you have changed your minds please contact me. I have three more available."

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Tech Info on Crankshaft Critical Speeds

http://www.prism.gatech.edu/~gte154q/ (Determining Crankshaft Critical Speeds)

Info on the subject...

http://www.bhjinc.com/dampers/precis...c_dampers.html

(B-H-J precision harmonic dampers offer maximum protection from torsional, axial, and radial crankshaft vibrations while adding minimum weight to the rotating assembly)


I found at least 3-different cars that have cars WITH torsional/harmonic dampers made for them by UR (despite their claims that they don’t make dampers for cars that need them – perhaps “need” is the keyword here…)

AND you can add the Acura CLS pulley to the list -- it has an inertia ring inside of the pulley (one person sent me some info and I checked with a buddy that knows a buddy over at Honda/Acura).

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If anyone is really interested, you should know the following:

1. All the literature seems to indicate that when used ONLY for drag racing (you move up and down past the critical resonance quickly, you might be ok. Drag racers, just keep those revs moving.

2. The literature seems to indicate that "road racers” who maintain fixed RPMs could have some serious trouble ahead.

3. There are some tests that could be done on the crank to detect if it being subjected to "strain". (NOW, THIS WOULD BE NICE. Not a test on an ACCORD, BUT ON THE CLS)

a. Check the heat output via an IR thermometer with laser pointer at the pulley -- when it puts out a lot of heat energy (like the M3s for racing), it is in need of damping at that frequency).

b. To those that are saying, "Hey, my car feels smooth" -yep, you also have some really cool motor mounts that would probably keep the engine feeling smooth with some pretty nasty vibration.

c. Any vibration would probably be of high frequency nature, so something to measure the jitter with rpm would let someone know at what rpms the engine is trying to bust the crank or beat up the front bearings.

d. I HAVE A SOLUTION FOR THE UR FOLKS -- here it goes -- do a test of the vibrations of the stock CLS pulley VS. their pulley. If they can show that their pulley is "somehow" making less vibration, then everyone can go toast themselves for a safe and cheap power maker -- ok? (All pulleys and accessories must be installed on the CLS engine during the tests)

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Here is a link to a site that carries UR pulleys and "lightweight pulleys with dampers" (sorry, not our car...yet):


http://www.extrememotorsports.com/g1cat/engine.htm

Notice how they have the same old UR pulleys -- with no dampers -- and they sell a high-performance version with a damper. Here is the "blurb" and is down the page from the UR pulleys (hey, they sell both -- ok)

"Unorthodox Racing Underdrive Pulley Setp

(Whole enchilada with crank pulley)

"Billet Aluminum Harmonic Damper [EXM1176] $349.00
Lightweight CNC Billet Racing Damper... this harmonic damper also works as a underdrive pulley thats helps increase usable horsepower while protecting your engine....


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Please read the Stealth site info – they have already been through the trenches over there and the article basically “gathers-up” the info. The important info is how to get all of the power and not have to blow an engine up to make sure it is a “good” thing…


So -- THERE ARE SOME SOLUTIONS and TESTS that will answer this in a non-destructive way. If some of you have a suggestion on how this could be done, I welcome it...


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Warranty excerpt from the UR download of instructions for an earlier CL (no comment):

“. Unorthodox Racing, Inc. is not responsible for voiding any original manufacturer warranty. All warranty claims must be returned to the authorized reseller, you …”

moomaster_99

BUT......they said it's okay.....

soopa

I'm gonna start calling you Eric Brockovich!

SiGGy

LMFAO, no doubt!

I'm just glad someone is paying attention to these things. Most people haven't a clue on the concepts.

cnatra

LMAO!!

Where do you find the time to gather all the info Eric ??

It's great you research all this stuff so we don't have to!

Nashua_Night_Hawk

Can we summarize as follows:

1) The Stock Crank Pulley does ahave Torsional Vibrations Damper (Called TVD) . An Elastomer Damper. The UR crank pulley does not.

2) The Torsional Vibrations Damper is NOT a Harmonic Balancer. Since, it is not intended to balance the engine. Such device (counter weight) is supposed to be on the crank shaft itself.

3) UR claims:
a) The TVD would reduce noise vibrations.
b) he TVD would reduce Torsional Vibrations.

4) UR claims:
a) The UR crank pullye is 0 gramm balanced (TRUE). So, it would make less noise and less vibrations.
b) The UR crank pullye is lighter and smaller than the stock pulley, therefore, it would show less/reduce the Torsional Vibrations to the point where the TVD is not needed. (Yet to be proven).

I believe the best to do now is to contact/contract a company to a Vibration Measurement test, such as this one: http://www.fluidampr.com/testresults.html (stock vs the lightweight AND DAMPED pulleys) (UR are not damped)

Please keep us imformed!

EricL

a. The stock crank pulley DOES HAVE an elastomeric damper.
b. The UR pulley DOES NOT HAVE any kind of damper (viscous or elastomeric)

(I wish I could make this a yes or no answer, but some of the problems are due to terrible descriptions for parts and the terms being used interchangeably by tons of people…)

a. TVD == HB. Well, yes and no. The terminology gets “misused” and some people call their TVDs' HBs and some people call their TVDs HDs. This just adds to the confusion… (So, if you want to be “dead on” correct about terms: BALANCE HAS NOTHING TO DUE WITH DAMPING – PERIOD!)

b. If a pulley is perfectly balanced from a rotational standpoint, it doesn’t have anything to due with “Balancing the engine” (e.g. Balance shafts will “balance” an engine.). If a pulley has any kind of elastomeric material or viscous fluid that allows a “chunk”/”ring” to “respond to”/”damp” vibrations, it is a TVD.

c. If the pulley is drilled or weighted to make it “unbalanced”, it should be considered a balancer and it has nothing to do with torsional vibrations. (NOTICE: I did not use the term “harmonic balancer” just “balancer”).

d. OUR pulley is a TVD. It is balanced, but has an energy-absorbing damper in it to absorb and reduce torsional vibrations.

e. THE TERMS ARE SO MISUSED and leaves such a gap for “semantic” games, that I would prefer to just use the term “BALANCER” (for removing an out-of-balance condition that has nothing to due with torsional resonance). I would love to just have the stuff called “DAMPER”/TVD for anything that tries to quiet modal vibrations/resonance (think shock/spring).

Both are true. They reduce noise vibrations and they reduce “twisting” that occurs at various loads and rpms. (Energy is being dissipated and a damper should not be confused with the “flywheel” effect.)

a1) This is the worst kind of hogwash that I’ve ever seen. If the crank and other assembly happens to be OUT OF BALANCE by .1 gram at 122-degrees and it just so happens that the “unknown” pulley from Acura had an offsetting weight, it could make that statement from UR FALSE.

a2) How to make your a) true: 1) Acura’s pulley would have to have no TVD (it does). 2) it would have to be proven that their pulley is better balanced (theirs probably is) 3) that any residual resonance in the engine was better damped due to the lowered mass of their pulley (this is not the general rule; however, rotational systems have analogs with translation systems [think spring, mass, damper]. IMO, it can go both ways.


b. The literature seems to indicate NO, but if someone will produce a graph, it’s a large chunk of HP to get, and it would be worth it. Hence, why not PROVE it with a graph like the other folks do? (No proof either way)

IMO, cake and eat it too time. If someone is willing to put the instrumentation on the car (as does fluidampr and show the graphs), there is no guesswork. I would love the HP, but don’t feel “warm and fuzzy” just yet…

jsims006

is the pulley from the acura 3.2 the same as the pulley from the accord 3.0?


(sorry to invade the acura forums with my accord questions, but at least we are from the same family)

SiGGy

The main purpuse of a harmonic balancer is not to balance the engine. It does what it literally means, balances the harmonics of the engine.

And a torsional vibrations damper is a harmonic balancer... as a harmonic balancer removes torsional vibrations... hence balancing the harmonics of the crankshafts torsion from the pistons firing...


I found this URL to help

EricL

First, thanks for the post – I found some typos and word order errors that were confusing about TVD's being called both HB and HD (I had two HDs)

I do have a comment regarding your “balance the harmonics of the engine….” There are various “harmonics” that are generated in some engines: V6 and I4 to name a few. They are the result of rocking and other modes of “balancing” that have NOTHING to due with a crank twisting. (That’s why I so dislike the term HB [Harmonic Balancer] – it is a diabolically confusing term.) I’m sure you know what is going on (the link your provided and the quoted excerpt are great) , but I would hate to have someone see the word harmonic and automatically assume that it is TORSIONAL in nature when it could be due to rocking and other “types” of engine inbalance

First, a side note:

And also found this, and thought this was "humorous:”


"Ray: With the term "Harmonic Balancer," I think we're finally seeing the influence of the flower children of the sixties in Detroit. The engineers who came of age during the hippie years realize that automobiles, by definition, are out of balance with the forces of nature. And in naming part of the car the "Harmonic Balancer," they were simply trying to bring the "negative vibrations" of the internal combustion engine in line with the peaceful forces of the environment

http://cartalk.cars.com/Columns/Arch.../March/03.html

More info on torsion types of harmonic balancing:

WHAT THE HECK IS A HARMONIC BALANCER?

MORE: http://members.core.com/~faldrich/harmonic.htm

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AND NOW for why the use of “balancer” and “harmonic” is such a source of possible confusion: V6 60-degree and V6-90 engines (bigger issue here) have some “balancing” issues that have NOTHING to due with the crank flexing due to “TORSIONAL RESONANCE”.

Here is an SAE paper describing a balancer that kills first- and second- harmonic rotating unbalance couples of a 90-degree V6 even-firing engine. (Notice that the word harmonic is used again and again.[However, they do refer to rocking and not twisting])


” Abstract
This paper describes the effectiveness of an Oldham- coupling- type balancer in reducing the first- and second-harmonic rotating unbalance couples of a90° V6 even-firing engine. It is shown that the prototype balancer can be configured to eliminate the residual, first-harmonic rocking couple usually remaining in a conventionally balances 90° V6 engine. Further, the Oldham- coupling- type balancer can be used to reduce the elliptical second-harmonic rotating couple to a horizontal rocking couple. The power consumption of the balancer was measured to be approximately 0.35 kW at 2000 r/min and 1.5 kW at 4500 r/min. “


http://www.isr.umd.edu/TechReports/I...0/TR_87-40.pdf


(A lot of “harmonic” terms being used – but in conjunction with the term “couple”)

(AND – this has NOTHING to due with the OUR TVD)!

JRock

Is this the post that makes the UR pulleys a bad mod to do?

See all this discussion and worrying is why I'm not getting them. I need my car to last me for several years.

mattg

J32A2 short block - only $1500.


the heads are the part that's really expensive. :o

SiGGy

It's an interesting topic/point(s) of view you bring up. I think no matter how you view it, it is truely a "harmoic balancer" even though it may have a dual purpose of balacing the crank. If the crank is off balance you are going to have vibrations/resonance. And as such the "harmoic balancer" will help alleviate the vibrations/resonace from the unbalanced shaft. As any resonsance is considered a vibration/harmonic.

I don't think I would switch to the new pullys myself. I really do believe it will hurt the longevity of the engine.

In all reality, no matter how well balanced the crank/pistons/rods are. It still needs something to dampen the shock from the pistons firing. Whether or not the crank has been balaced internally or from a counterbalance on the "harmonic balancer" the main purpose of the "harmoic balancer" is to dampen the shock from the power stroke. Any engine will suffer long term without it. However the "harmonic balancer" can have a dual purpose if it is able to absorb the vibrations from an out of balance crank... Unless it's a 1cyl, I can't imagine a weight counter balance on the crank externally making any bit of a difference on a 4,6,8 cyl engine. As it is always rotating between a difference stoke and (intake, compression, power, exhaust) cylinder constantly. Most crank shafts have counter balancing on them already. The machine shop will even blance and blueprint your engine. But they certainly won't tell you to run without the harmonic balancer. Even though the crank has been balanced near perfectly.

Just upgrading to a fluid dampener will help longevity of any engine. By removing more resonance from the crank in a much broader rpm range.

It is possible that UR crank pully can resonate/absorb well at the frequencys that are emmtied during the power stoke at specific rpms. This would have to be proven with a scope. However the resonance of the UR crank pully could be calulated based on its shape and density. It would be hard to know what frequencys the crank shaft is subject to produce without a scope.

(excuse any typos I'm pretty tired, I'll check it for errors in the morning) heh

LOL, ya that quote you posted is hilarious! I don't even know what to say to that.

Nashua_Night_Hawk

Okay,....

In short:

a) The Stock crank pulley has an Elastomer Damper Type TVD.
b) The UR crank pulley does NOT have a TVD.

The $64,000 questions:
a) What are the negative consequences of runing thhe UR crank pulley that does not have a TVD. Will it destroy the CLS engine?
b) Will the UR pulley show less Torsional Vibrations than the Stock Crank Pullye?
c) How we can test ( at low cost ) the Torsional Vibrations on the stock pulley and on the UR crank pulley?
d) Can someone contact am Acura/Honda Engine Design Engineer for a definite answer?

Thanks for all your effort!

Nashua_Night_Hawk

The VQ 3.5L and the VD30 engine do NOT have a TVD.

So, why it is not a problem for VQ not have a TVD?

Here are the pic:

Nashua_Night_Hawk

On the other hand Honda Prelude Engine has a TVD as ours. Here is what Prelude Owner has to say about the UR pullye and bearings going bad.... NOT good!

Performance Impressions
Once we got the belts adjusted and double checked everything, it was the moment of truth. The car started without a problem, and idled fine. We checked the alternator and it was putting out a steady 14.4 volts at idle even under a slight load. I went out behind Danny's where there is some industrial buildings to do a few 0-60s on the GTECH. I really botched the first one up, but the second one was a 6.29 sec!! I am sure that is a fluke, but I have not tried to reproduce it yet. I decided not to do anymore runs because of the amount of traffic.

The engine seems to pull slightly harder in first and second, but there is a noticable difference in third gear. Also, throttle response is greatly enhanced. One benefit that I like is that the A/C no longer drags on the engine so much. The only side effect to this is that the A/C is not as cold at idle. When driving around, the A/C is as cold as stock, however when idling, the A/C is slightly warmer than stock. Not really a problem in my opinion, even with the hot Texas summers.

I have now had the pulley on for about 10000 miles, and I have had absolutely no problems. I have been sent e-mail concerning the AEM ad that states that the crank pulley contains damping material that is "critical to engine life." True, the stock pulley is potted in a rubber compound, but I suspect this is to damp vibration from the p/s pump, the alternator, and the A/C kicking on and off. I haven't noticed any increase in engine vibration and engine sounds fine at idle and WOT. I am not saying that the guys at AEM don't know what they are talking about, but on our particular application, I don't think that changing the crank pulley will affect life at all. Also, the crank pulley is not a harmonic balancer; that is what we have the twin balance shafts for. There is much debate on this topic, and this is just my opinion. If you ask three different people, you will get three different answers!

Update- READ!!!
Since the original writing of this article, a few of us with these pulleys have done much more research. Billy has recently had his engine built up by Larry at Endyn. Upon dissasembly of the engine, Larry reported that the bearings, with 40k miles on them, looked like they had "a hard life." Roughly 20k of those miles were before the pulley, 25k of them after.

We have no idea what the bearings from a 45k mile engine are supposed to look like, but by comparing the #1 bearing to the #5 bearing in Billy's engine the difference is stark. The # 1 has deep grooves which have worn away all the original machining marks, still visible on his #5 bearing. Larry also reported that his oil pump was so damaged as to be unusable.

While we aren't going to detail all the arguments for or against pulleys, or tell you what you should do with your daily driver or track-only car, we (and Larry feel that the damage in Billy's engine far outweighs the benefits seen by the pulleys. We (including Larry) feel that the "accessory" pulley kits offered by companies like Unorthodox should NOT cause the same damage we think the crank pulley did- the harmonic balancer is weighted and damped to absorb the impulse energy created by the accessories as well as the crank itself; while changing the pulleys on the accessories will alter the characteristics of the load, we feel that any change would be a positive one. - Todd Marcucci

Full article is here: http://www.ntpog.org/reviews/underdrive/pulley.shtml

The bad wearing of the bearing problem is in 100% opposite with what UR is claiming:

4) "Will the underdrive pulleys cause my engine to have premature bearing wear ?"

This is a fear many prospective owners have and it is a valid concern since we are dealing directly with the rotating assembly. It is, however, a fear with no basis in fact. The fact is that our pulleys have the opposite effect on engine bearings. The combination of tight tolerances, quality control, perfect balance, and dramatic weight loss versus the stock pulleys reduces the stress on your engine extends the total service life you can expect from your engine. Engine bearing problems are purely associated to poor engine maintenance, use of heavier than factory recommended oils, improper engine building practices which includes poor balancing, excessively revving engines when they are cold, and owners expecting their factory oil pumps to handle engine HP outputs 2-3 times over stock HP levels.

Nashua_Night_Hawk

Another site: http://www.240sx.org/faq/articles/pullys.htm

Quote:

Harmonic Dampers

From what I have picked up over the past few months talking to various people about underdrive pulleys is that the UR eliminates the stock harmonic balancer. According to the last few posts about the ASP pulley, apparently it makes use of a harmonic balancer. From my understanding, the harmonic balancer is needed for the KA. If anyone else can add...please do, because I wouldn't mind finding out some more about them!

Here's an article from 'National Dragster, Racing Technology' about harmonic dampers:

Good Vibes
Contrary to what you might think, a crankshaft really isn't a solid, immovable object. The crank twists and bends relative to the loads placed on
it by the respective pistons and rods on each throw. General Motors' tests have shown that the crankshaft in a 350-cid small-block prepared for racing can deflect considerably at 8,000 rpm. A crankshaft also has natural frequencies. Coupled with the frequency of the torque inputs and resonance, severe crankshaft vibrations can result. The result is outright crankshaft failure if a damper of some sort isn't used to still these vibrations. Not that long ago, it was common to use an aluminum hub on the nose of a drag race engine. Bad idea. The end result was often a two-piece (or more) crank.

The Baddest Vibes
There's more here than outright crankshaft carnage. When harmful crank vibrations aren't kept in check, valve timing can be disturbed (often dramatically), oil pump driveshafts can break, wet-sump oil-pump gears can shatter, timing chains can stretch and break, and shifting gears in a stick-shift combination can become impossible, or, at least, difficult. Main-bearing wear is common when the vibes aren't controlled. Often the thrust surface of the main bearing shows signs of major degradation. Evidence of main-cap-to-block fretting, chafing, or galling is common. Rod bolts can continually loosen. Ditto for little things like valve-cover bolts. Rod bearings can blacken (the same applies to the back side of the connecting rod crank-pin hole). Valve spring life can become dismal. Flywheel and converter bolts can loosen. Flywheels can physically break. The torque converter pilot or hub to gear surface can fret or chafe.

All of the above are signs of unchecked crankshaft harmonic vibration in a race engine. Usually, the symptoms go hand in hand with a non-functioning
damper on the nose of the crank or when a simple aluminum hub is installed in place of a damper. Also consider that the damper hung on the nose of your engine is not a balancer. In reality, it balances nothing. The main purpose of that big hunk of metal out front is to absorb harmonics. Harmonics and balance are two decidedly different things.

The Range of Motion
The operating range of an engine along with the speed at which an engine accelerates can have a profound effect on the damper requirements. Some dampers are "tuned" to operate at a specific rpm level. That's fine for an engine that runs at a constant or relatively constant speed (a good example is a diesel highway tractor with a dozen or more forward gears), but if the engine is accelerating and decelerating over a wide rpm range (as in a drag race application), then frequency tuning becomes troublesome. Case in point is a widely publicized test run by Katech for General Motors. Four aftermarket dampers were tested on a 427-cid small-block (4.125" bore x 4.00" stroke). From 3,112 rpm to approximately 6,500 rpm, none of the dampers twisted the crankshaft more than 0.6 degrees. But after 6,500 rpm, the test proved that crankshaft twist increased by a considerable margin in three of the dampers. At 7,893 rpm, one damper showed 2.0 degrees of crank twist, another showed 1.7 degrees, and another showed approximately 1.25 degrees. The last damper, an ATI model similar to the assembly pictured, showed 0.28 degrees of crankshaft twist. From my perspective, outlining this isn't to compare dampers but to show that crankshafts definitely do migrate. They're not immovable objects, and they do twist.

George Rogozin
Email: rogoman@home.com

Nashua_Night_Hawk

Another negative result of lack TVD on a race engine

http://www.rolmfg.com/Technical/HPI/Cranks.htm

cnatra

I want a VQ 3.5L !

(G35 coupe would be NICE!)

EricL

Nashau:


Look, if people want to get the pulleys, let them get them, it's their car.

I think there is now enough "anecdotal" evidence to show that there is great potential to cause accelerated bearing wear.

There are now two people (one Stealth, one Prelude) that have had a look at the bearings after some miles with the UR pulleys and weren’t thrilled. The question is “how much” damage, if any is done – well, that’s the question and who knows for sure…

I spent time on the phone with a lot of people who DO NOT want to have their name used. In my mind and in the mind of a few others IT IS A TVD. UR doesn’t think it matters.

(There are some other points that I believe have some problems with them, but there not of any real import to the issue of -- "what to do and where to go now" )

AS far as second guessing the designers at Acura, I feel that it would be "nice" to get an opinion from them and have them say, "don't worry, we worked with UR and here is your new warranty (call me pessimistic). IMO, there would be so much red tape, that getting official Acura OKs (at least to my mind) is a long shot (A VERY LONG SHOT). Who in their right mind wants that added liability?

So -- yes, the pulley look like real power makers.

So -- yes, the Maxima pulleys shown in your picture don’t have a TVD (Hey, there are people who are debating the lightweight pulley issue on the Maxima and I sure can’t see a damper.) If there wasn't damping material (elastomer + internal ring) in our pulley, I'd take the chance... ok).


The testing is well documented on the fluidampr link:

Methodology (of sorts) (it's just a suggestion and I haven't gone to the "experts" for comments -- oK)


(WARNING: NERD/TECH GEEK STUFF COMING)

Find a lightweight optical wheel with alternating clear/black white/black tick marks. Or find some white tape with contrasting lines on the tape. Wrap the tape around the outside of the pulleys (it would NOT alter the balance of the UR pulley do to its super light weight). (There would be a small discontinuity where the tape lapped, but…)

The idea is to get a set of pulses from an optical or magnetic sensor). It's been a while, but have used a LED (emitter) with pin-diode (light detector) to sense the fast moving crank via reflected light (the bracket would not have to be that close).. The output would need some cleaning up, and this would give the raw pulse output. (I don’t have the part number handy, but the device was in a single plastic block and was made to operate from 1- to 6-inches in range (depending on the contrast of the “markings” on some tape, etc).

The pulse output would go to a FM discriminator (one would look for a change in frequency in a desired range). One way is to take a Phase-lock loop and pick-off the output voltage coming from it’s phase detector, then through a low-pass filter, and into its voltage controlled oscillator (VCO).



(R is a resistor)
(C is a capacitor)
(Can be replace with any LPF (low pass filter))

(The two make up a loop filter)


(Fin in the pulses from pulley [range of 2 to 7] x “ticks” per rotation)
(Frequency to volt converter)



------

Note: Pll’s VCO can be replaced with AD-537 wide range voltage to frequency converter. And 1 of the 3 phase detectors (depends) can be used from the 4046 (probably #2).

Signal -- marked as (2) -- is the “jitter” / FM signal/vibration signal that goes to FFT, scope, data acq. card, etc...

This circuit above is basically a wide-band PLL (phase lock loop) and if someone grabs the output of the phase detector, they now have a cheapo FM discriminator (about $20 bucks worth of parts)

OR



Using just a 4046 (and seeing if the track and capture range will do:



----



This circuit just uses one of the xxx4046s, and/or can be “enhanced” by substituting one or more of the “subcircuits” inside the package with devices mentioned in the links included below.

Choose your own method: analog, digital, or heck, just try using the F to V converter, and post process the V signal on a pc with a data acq. board and some matlab or other programs with FFT and DSP function...


Before the quibbling begins, this is just “a design idea” (hey, if there are problems – make it better and keep going...)


See the following PDF and Figure 21.

http://www.national.com/an/AN/AN-162.pdf

If there are “problems” with the PLL, the circuit in Figure 22 can be substituted for the PLL’s VCO.

A typical PLL, would be a 4046 with phase comparator #2 used.

http://www.semiconductors.philips.co...046A_CNV_2.pdf

http://www.iweil.com/devices/pll/ti_4046.pdf

http://www.analog.com/library/applic...tage/AN277.pdf

(For a wide range and linear voltage to frequency converter)
http://www.analog.com/library/applic...tage/AN277.pdf


One of the two devices would probably have not problem covering the frequency range of interest (2K – 7K)

An engine is set to various rpms, and the “jitter”/ vibration (change in pulse repetition frequency (FM signal)) is then fed to a FFT. If there is no “jitter”, there will be no signal from the VCO.

If there is “jitter”, the change in frequency with time will generate a voltage that corresponds to change in phase/frequency.

So, if there were no jitter at a steady engine speed, a FFT would show no “output” with a non-varying DC level coming from a Phase detector.

If there is “jitter”, there will be an up-and-down level change that is the FM signal. The FFT of this will show the fundamental frequency with its harmonics.

Finally, you can compare the “jitter” on the stock pulley and chart the FFT at each RPM (A frequency domain plot is produced for each RPM of interest)

THEN

You compare the “jitter” on the UR pulley and chart the FFT at each RPM (A frequency domain plot is produced for each RPM of interest).


If you show that the UR pulley has LESS vibration that the factory pulley, you have gone part of the way to show that there is no “additional” vibration due to the UR pulley.


THE above-mentioned “no-dyno” tests are not “robust” and if any vibration was detected (UR vs OEM) with no-load engine test, there is something nasty going on.

Note: A good look at the fludampr notes will show that they are doing a more robust test by sweeping the engine under load (this will increase the power pulses being applied) to the crank and increase the crank flex and subsequent torsion and resonance.

Now, your looking at not just buying or renting the test gear (as mentioned on their site and there is no FM discriminator mentioned by test device name) or “cobbling-up” the Discriminator, but NOW we’re talking some dyno time and the “gear” better be “good to go”…



YMMV

Nashua_Night_Hawk

Great Work EricL,

Why not someone or better those 40+ who bought their pulleys call UR and ask them to do some real work Torsional Vibrations Testing as outlined in your analysis.....

Great work... let us be informed, I am starting to be biased toward selling or returning the pulleys to UR.

EricL

IMO, if you have an out-of-balance crank, you balance the sucker. The crank, rods, pistons, pulley make up a system. As such, there can be "out-of-balance" forces that will NOT manifest themselves as torsional/twisting "vibrations". The "couples" can end up as various rocking motions (e.g. the back of the engine wanting to go up, while the back wants to go down and so on). The imblance is manifested in two planes.



Here is a perfect example of a simulated shaft with a couple imbalance. You are correct in that there will be a torsional product that results from the "couple" (or moment imbalance), but the literature is pretty clear that the imbalance should be corrected through appropriate methods (in this case, the removal or strategic placment of weights will remove the couple). The addition of the "torsional damper" will not remove the "beating" that the bearings are going to get. (AS an aside, I did find an off-the-engine damper on the web. So, I will provide that and it's even made for an 8-cylinder engine) Quoting from my electric motor book, "From a theoretical standpoint, the aim is always to achieve a zero-unblance condition. In practice, the requirement is to reduce the unbalance to a point at which the unblance forces have a negligible or non-harmful effect on part operation."

So, the torsional damper (viscous or elastomeric) is really designed to cut down "shock" on the "whipping" that the crank experiences due to the rotational forces and harmonics that show up as a torsional/twisting force. It is not there to remove the "continuous" torsion that is a result from a lousy dynamic balance job! (You could tell by seeing that the vibration increased by the square of engine speed and was not directly related to load [e.g. -- you would get the problem with an electric motor driving the crank or flywheel with all the plugs out. OUR TVD would be a lousy fix due to the spring/damping qualities of the rubber. The viscous damping in some TVDs is analogous to a "shock", where the rubber/steel ring damper is analogous to a spring/shock combination. With the "rubber"/"metal-ring" assembly tuned to a “narrow frequency band”, it wouldn't help the problem at higher rpms and would still have the rock...

Here is the reference to the V8 balancer:

Link is https (secure): https://www.spoperformanceparts.com/...html?CATID=525

10216339 8" Torsional Damper

(Notice that they don't mention the external balance feature until it gets into their description)

'An externally balanced 4.00" stroke crankshaft used in a 454 and 502ci big-block Chevrolet engine requires a counterweighted damper for proper engine balance. This harmonic balancer is used with LS-6 and LS-7 engine assemblies.'

AND here is something with a seemingly identical "short description":

3879623 8" Torsional Damper

(Notice this one is made for an internally balanced crank)

'This 8" diameter torsional damper is designed for all internally balanced big-block V8s. It was originally used on 1967-69 427ci engines'

(Interesting -- hey? Both V8s, and both need TVDs [aka TDs], but only one is counterweighted.)



A full set of tests would go a long way to get one on my car. I wonder if one of the guys who make the lightweight viscous damping models could be “induced” to make one for our car???? .


Well, I’m more concerned about the “harmonics” as they “stack-up” in an additive fashion to create sympathetic vibrations in the crank that can be “damped”. It goes to the very heart of an internal combustion engine that some amount of flexing is going to result from a small blast going off.. And once again, the out-of-balance issue related to the “couple”. So, to be very clear, are you talking about a particular “couple imbalance” (as in the case of an electric motor’s rotor) creating torsional force?


RE your quote: “I can’t imagine a weight counter balance on the crank externally making any bit of a difference…”

See the early references to this same issue. They really do make them.


IMO, I don’t know/think anyone would be too thrilled with a suspension system with shocks that were made out of rubber.

Viscous dampers (analogous to dash-pots, etc) is a pure damper and doesn’t have a resonant quality. I’ve mentioned it being analogous to a shock absorber or “damper”; it also just like a resistor in electronics. Its damping is NOT related to frequency and/or time.

OTOH, rubber (or elastomers) have a spring quality to them (they push back [have a restoring force, just like a spring) and they also damp (Check out the bump-stops in the CLS’ suspension .)

RE: resonance of the crank pulley… I’m not sure I’m tracking on this one. Once a solid and homogenous pulley becomes part of a system (without articulation) as is the case, the object’s resonance isn’t important. (An example would be like me measuring the modal vibrations of a dowel pin and then driving it into a cylinder or vice-a-versa. The combined resonance would differ depending on the materials properties of the dowel pin or cylinder. But, I’m not aware of any equations that allow the two to be combined. If you know of a reference or other info, I would be very interested.

AND

Perhaps someone will propose a “Vibration study of UR pulleys group buy”

Nashua_Night_Hawk

Please let us keep this research going strong!

Nashua_Night_Hawk

Hi,

I recently bought an Unorthodox Racing Ultra SS street under drive crank pulley for my Acura 01 CL Type-S. I did not install the UR pulleys, yet. After some more research, I found out the stock crank pulley has elastomer-damper-type Torsional Vibration Damper (TVD). The Unorthodox Racing crank pulley does not.

After reviewing your site, I understand that the lack of TVD would be very destructive to the bearing and journals of the crankshaft. Now, Unorthodox Racing claims that TVD is just to reduce the engine noise/vibrations from reaching the cabin. Hence, a mere cabin comfort enhancer. Moreover, UR claims that their crank pulleys would reduce Torsional Vibrations.

Since UR never did any Torsional Vibrations testing on their pulley and you already did and have the expertise to do so, I wanted to know, if it is possible to do Testing of Unorthodox Racing Ultra SS street under drive crank pulley on Acura 01 CL Type-S Compared to the stock crank Pulley? If so, who much such testing would cost an average Joe?

The plan is to ask an Acura CL-S owner, to volunteer his car to be tested with and without the UR crank pulley.

Thanks a lot for your help.

Regards,

Samer007

To do a Torsional test you would need two torque transducers and to encoders (for speed). One would be placed at the source of rotation the other at the recieving end and do comparision. I have done some torsional measurments on supercharged engines. And it was not easy, and was very costly, even though we own the equipment (that reqires the engine to be unmounted).



FYI, here is a cutout of the crank pully (#14)

BNut

Woot!

You guys are awesome! Its nice to see a group of people determined to get to the bottom of a mystery!

The tire rhetoric of "UR has been making pulleys for a long time, don't you think they know what they are doing?" Doesn't cut it for me.

I already know for a FACT that they royally screwed over the 3rd Gen V6 Eclipse owners and then pulled the product from their website after Eclipse owners started getting check engine lights shortly after installing the pulleys. The president of UR then made posts on the neweclipse.org message board stating the DSM platform was "weak" and making other excuses why they pulled the pullies from their website.

Go to www.neweclipse.org and ask, "What do you think about UR pullies?" and see what happens afterwards.

BNut

UR is having an open house on July 20th at their Lond Island location.

Check here for the details:

http://www.v6accord.com/forums/showt...5&pagenumber=2

Might be a good way to come armed with the facts and get this settled once and for all.

Nashua_Night_Hawk

For completness, this is the reply I got from Vibratech:
Mr. NNH,

Being an employee for a company that manufactures TVDs, I would like to see one on every engine. The Honda engineers put one on for a reason. Car companies do not spend frivolously. As for testing, we are extremely busy with our projects and would not be able to accommodate your request at this time.

Sincerely,
Scott

typeR

hey NH...think aobut this...how easy would it have been to make the stock manifold flow like the comptech headers....wouldnt have taken much...yet the acura engineers let 32 hp slip past them...howabout RES for that matter...granted we cant buy one but asumming it is what it's supposed to be...a simple enlarged intake cover....12-15hp missed again....

Nashua_Night_Hawk

In case of the TVD is totally the opposite!,

Acura could have done the same as Nissan, gives the CLS a solid steel1-peice crank pulley. I am 100% sure that such non-TVD pulley is cheaper than the stock CLS pulley (TVD).

Why Acura decided that CLS has to have a TVD crank pulley? Simply for a reason, to dampen the Torsional Vibrations.

moomaster_99

Everyone knows that exhaust manifold is one of the last things to be considered in a vehicles design by Honda and every other car manufacturer for that matter...that's why Nissans gain a considerable amount of power with just the addition of a new Y-pipe(?)....they factor in cost of materials and labor...(iron v. ss and casting v. TIG welding.)

typeR

ya but 32 whp...come on it didnt take stainless and tig welds to get all 32 just the shape probablly made the biggets diffrence...
"Introducing the new 2001 275 hp acura cl typeS" ...think of how much better that would have sounded....15 hp from the iron cast manifold was doable....
my point is somethings are done just because thats how they do them ,not because there isnt a better way...

EricL

Stainless == $$$$

BTW, depending on the car, there have been some examples of factory manifolds (BMW 2002ti) that was pretty good. It was a 4/2/1, but didn't have any ugly right turns that the Acura CLS manifold does.

Now, as to why they don't soften the bends a tad -- I have no idea. Not being a iron-casting-guild member", I don't know if there were other considerations given to some of the 90-degree gas flow “designing” that’ up near the top of each header bank. At the very least, it makes one wonder about the flow length on the outside cylinders…

You would hate to think they did to keep ANY MORE hp from getting out of the engine.... I could probably toss about 8-different guesses and who knows if they would even be close...


IMO, a more “apt” analogy would have been if they had put a pulley on the front with a damper inside it that didn’t articulate and just weight a ton more without being “active”…

EricL

AS in direct measurement...

Did you look at the note from fluidampr?

I assume your were looking at the actual flex (not as a general resonance but as an absolute amount of twist (at load and speed) -- tell me if I'm wrong.

Did you guys ever test to breaking?

And

Where did you mount the sensors (im very curious -- would mind some extra detail?)

TIA

Chopsie

This was on the Similar posts at the very bottom of reading another thread.
Now after wanting UR pullied. I found this to be very interesting, yet complicated at the same time, since a lot of it I do not understand. Thought it maybe useful to others and to see if anyone has any additional comments as to whether they have solved this potential problem with the UR's.

phipark

Summary? I know I will be looking into the URs later on down the road.

darrinb

i actually heard about this from another guy not on the forums about the vq 3.5, i havent had any problems with my UR pulley, i only have the crank

allmotor_2000

It would be very interesting if I had tried the Comptech Flywheel/Clutch without the UR Pulley (as all other users are doing) and see if it was indeed some sort of resonance which caused the pressure-plate travel-stop pin to destruct everytime!

CL_Cha

does the aem pulleys have a tvd?

Chaptorial

Still no problems running all three UR pulleys for about 4k miles.