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FFP ud pulley...a hazard???


futuretgper
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Answering a question from above: The pully is actually has very little under-driving... Actually, some pully KITS make the crank pully smaller and the water pump and alternator pullys also smaller to compensate and drive them the same speed they were intended to run, while slowing down the A/C and power steering a bit... Most of the power you get out of an underdrive pully system is from simply making the pullys lighter... rotational mass is worth something like 10*static mass... If you take one pound off of rotational mass, you're effectively taking 10lbs off of the weight the engine feels like it's pulling...

 

On a side note... FWIW, With a 60* V6 being naturally balanced and not having a balancing weight on the crank pully, I don't immagine it's a big deal, BUT, knowing the automotive industry pretty well, I'll tell you, these guys will give their mother's grave plot for $0.05 per vehicle cost savings (because it adds up over millions of vehicles), so EVERYTHING in a car is there for a reason! I immagine most of the reason for the rubber damper is belt life... If you're pulsing a belt with some known strain on it, that is going to wear a belt (and probably the accessories) out faster than if the belt is moving a constant rate...

 

[rant] BTW, I know I'm not the only one that gets annoyed when people (COUGH *Aaron* COUGH) turn a thread... every thread... that has several sides and pros and cons into a "YOU ARE A COMPLETE DUMBASS IF YOU DO NOT AGREE WITH ME" thread... In any technical discussion, there will almost always be more than 2 sides, and given what I said above, this has had a TON less research put into it than the stock system, which is there for a reason. Saying that nobody has had a problem yet with this mod, so there are no reprocussions is kindof like saying "we all are using WD-40 instead of oil in our engines and have been for at least 2 days, and nobody's pitched a rod yet, so it must last FOR EVER!" [/rant]

 

Mike

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Saying that nobody has had a problem yet with this mod, so there are no reprocussions is kindof like saying "we all are using WD-40 instead of oil in our engines and have been for at least 2 days, and nobody's pitched a rod yet, so it must last FOR EVER!

 

Hope your not talking about me, I may be arguing but I dont call people names because they have an opposing opnion.

 

thats a rather extrme example and i think that theres alot more miles and years of running cars than that. 2 years and 60,000 (engine has a total of 86k) miles so far I would say its a relaible mod. There are people that have had it even longer with even more miles.

 

I would say you are right on the belt life comment as I do go through belts faster with the pulley than without.

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How much faster would you say?? Is it ridicilously fast, or just a little bit faster than normal??

 

I replace them every 4-6 months, though I drive ALOT too, I average about 30k miles a year.

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Saying that nobody has had a problem yet with this mod, so there are no reprocussions is kindof like saying "we all are using WD-40 instead of oil in our engines and have been for at least 2 days, and nobody's pitched a rod yet, so it must last FOR EVER!

 

Hope your not talking about me, I may be arguing but I dont call people names because they have an opposing opnion.

 

thats a rather extrme example and i think that theres alot more miles and years of running cars than that. 2 years and 60,000 (engine has a total of 86k) miles so far I would say its a relaible mod. There are people that have had it even longer with even more miles.

 

I would say you are right on the belt life comment as I do go through belts faster with the pulley than without.

 

No, I'm not talking about you... I am talking about how aaron keeps calling people assfucks when they don't agree with him... Anything that goes toward a + or - on an issue without calling names is fine by me (even joking is fine, do it all the time)... I agree, this is probably an OK mod with an engine that doesn't have a counter-balanced crank pully... I guess I just get tired of people saying they added some shit to their oil or are running some fuel additive or running without a filter or some shit for like a week and say "it hasn't blown up yet, so it's not going to degrade the engine in any way."

 

I guess it has to do with the age and background of the people on not only this board, but most boards for affordable cars... Just young and innexperienced for the most part because this may be their first car, or they're in HS or something... I didn't know much in HS either... I mean, I'd rebuilt engines and stuff, but lets just say that I'm glad I don't own any of the engines we rebuit anymore if you know what I mean... didn't know about plastiguage or crank end play or anything like that... "hey, it looks OK... fire it up, we got oil pressure, dial in timing... it's good!" I knew fuel injection basics and such, but didn't know what EXACTLY it took to get an engine to run on FI, and didn't know all the circuitry and programming in an ECM... you remember being in HS... Mind you, there's nothing wrong with innexperienced people... we all were at one time, and some still are... I guess I'm just not used to it much any more... man, I'm tired... I can tell I'm off on a LARGE tangent...

 

Mike

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how would that work anyway, like ignore user? it would block there posts? what if there useful or somthing, that doesnt seem like it would make much sense

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Guest TurboSedan

:lol: i am definately looking forward to the ignore feature.

 

anyways, i was thinking of what DaveFromColorado was saying about the TQ converter taking up some of the vibrations...

 

so what about the FFP pulley on a car with a manual transmission? well anyways, i still wouldn't hesitate to install an FFP pulley on my car.

 

hell, TD guys completely remove the balance shafts from their engines all the time. my brother has already done that to two of his cars. the TD 2.2/2.5 is internally balanced just like our 60*V6 engines, but they are rather notorious for being buzzy and that is really the only reason the balance shafts are there. alot of 2.2/2.5 engines didn't even have them to begin with, like the engine in my GTS.

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Don't worry...the "ignore this user" button is coming. And I know the first person I'ma choose :lol:

 

who? me? or the "other guy?"

 

Im pretty sure he doesnt mean you.

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in the manual transmissions (I just heard this from my Machinist) the springs in the clutch disc itself will work as a vibration absorber - but if an engine is properly balanced you won't need any type of vibration dampener and the only reason they are put on the cars is in the case of flawed bearings or other parts from the factory.

 

--Dave.

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in the manual transmissions (I just heard this from my Machinist) the springs in the clutch disc itself will work as a vibration absorber - but if an engine is properly balanced you won't need any type of vibration dampener and the only reason they are put on the cars is in the case of flawed bearings or other parts from the factory.

 

--Dave.

 

right, and no matter what on a factory engine there will be imperfections. No matter what unless you rebuild the engine completely balenced and honed properly.

 

But stock specs are tight enough that baleance isint an issue with a simple UD pulley.

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if the balance on an engine is off by even 3g (grams) you'll have a serious vibration - the usual imperfections in engines from the factory are usually along the valve-train and in the main bearings - you almost never see bad rod bearings.

 

*Typically* the only engines that will have an external balancing pulley are race engines that are set up that way on purpose because if someone stole the engine from the shop they wouldn't have the proper flywheel or crank pulley to make the engine function even decently thus making it worthless. there are some engines that have factory made external balance pulleys for their engines, but I cannot thing of them off the top of my head.

 

remember, we're only talking about harmonic dampeners (the micro-vibrations from all the metal to metal contact)

 

Before you step up and try to make me look like an idiot, learn to spell correctly, get your facts correct, and be prepared to learn something every now and then. Hell, you quoted me and still spelled it wrong!

 

--Dave.

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in the manual transmissions (I just heard this from my Machinist) the springs in the clutch disc itself will work as a vibration absorber - but if an engine is properly balanced you won't need any type of vibration dampener and the only reason they are put on the cars is in the case of flawed bearings or other parts from the factory.

 

--Dave.

 

Yeah that big force that shoves the piston down could never cause any harmonic vibration. :roll:

 

 

You obviosly can get away without the balancer as many appearently have on the 60 degree V6 but if GM put it there it is there for a reason. I have learned over the years that things break and sometimes for no good reason. I myself find no want or need to increase the chances of that happening.

 

If harmonics are a non issue in a balanced motor that explain to me the reasoning behind better than stock dampners for built motors?

 

Underdrive have been proven time and time again to have little to no gains on many different cars and for the most part are a huge waste of money unless you plan to rev the car beyond its stock setup and would then be putting undue load on the accesories.

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Guest TurboSedan

Before you step up and try to make me look like an idiot, learn to spell correctly, get your facts correct, and be prepared to learn something every now and then. Hell, you quoted me and still spelled it wrong!

 

--Dave.

 

yeah like we haven't heard that before :roll:

 

no one was trying to make you look like an idiot Dave.

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Sorry Manticore - long day at work, home with the baby which Jax was at work this evening, insert other excuses here - I realized that you weren't arguing afterwards - I'd edit my post but that'd make me look even more foolish, again sorry ...

 

Anyhow, Biff ... the reason better "dampeners" are offered for the larger engines is simply because most of the people who are using them, don't have the engine machined to match the pistons and rings, and they don't have a fully balanced rotating assembly - with a slightly off balanced assembly you will have more harmonics then usual, it's also used for improperly tuned engines.

 

And as for your thought about the force against the piston creating a vibration force, on a properly tuned engine the force against the piston works more as an expanding cushion "gently" applying the force against the piston in a downward motion which is connected to the crankshaft via the "connecting rod" which is what turns the reciprocating force into a rotating force, if you are getting anything that may cause these harmonics then you are experiencing KNOCK at which time you will have problems with either crushing your upper rod bearings, lower main bearings, tip ring or ring land, the connecting rod, or the piston itself - it's this knock or detonation which causes the premature failure, most often due to an improperly tuned engine either because of the fuel, or the ignition, so a stock engine which had been blueprinted, then had the parts made and then assembled and set to the specs which the blueprint required, you shouldn't have a need for a dampener, and with today's technology you will see that the "sprung hub" clutch disc's and torque converters will absorb any of the extra vibrations that may be due to someone abusing their car way more then to be expected.

 

Older engines all had them because they were put together with substandard technology by today's standards and getting the perfection that is able to be used today was just not available.

 

As you can see, if you have a knock sensor, and an automatic transmission or a "sprung hub" clutch disc on a manual transmission (stock clutches are sprung hub style if you're wondering) then you don't need to worry about the underdrive pulley not having the added weight of the rubber ring (if it's even on there)

 

any further questions?

 

--Dave.

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It will all come down to how you interpret the information out there. Here's a shetload of reading for ya to form your own conclusion:

 

AEM, an aftermarket pulley manufacturer doesn't recommend replacing the crank pulley for the following reason:

 

'Vehicle manufacturers have thoroughly investigated the use of torsional vibration dampeners and conclude that their use significantly reduces NVH (noise, vibration and harshness). Furthermore, manufacturer and independent research shows that torsional vibration dampeners are critical to engine life where long-term use is intended. Removing the torsional vibration dampener from an engine can be highly detrimental to its long-term operation!'

 

Interestingly, Unorthodox Racing, I would say the biggest pulley manufacturer on the market, has the following info on their website:

 

"Is my crank pulley a harmonic/torsional/vibration damper or a harmonic balancer?"

These days, people are getting their crank pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term that is 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 that Unorthodox Racing offer utilize a counterweight as part of the pulley as the engines are internally balanced. (Reference to the 2.0L D-Tec found in the Optra-Optra5 line)

 

The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that looks 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 that in these applications, this elastomer is somewhat inadequate in size, as well as life span, to act as an effective torsional damper. If you look at the pulleys on some of the imports there is no rubber to be found at all. Unorthodox Racing 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 that with their pulleys you will hear a ton of noise or feel more vibration from your engine compartment. Most who have installed and driven a vehicle with their pulleys will notice the engine actually feels smoother. This is a natural result of replacing the heavy steel crank pulley with a CNC-machined aluminum 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. (Read: RICE)

 

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, displacement, inline, V configurations, power output, etc., do determine when and how these harmonics and torsional movements occur.

 

Again, there is a lot of internet hearsay about the 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. I figure that after reading this you will understand the crank pulleys better.

 

So the question is simply whether the pulley reacts as a dampener for frequencies generated by the internal components. I recall reading why they were invented in the first place...as way back in the golden years, when parts in huge V8s were being swapped for more RPMs, balancing wasn't the problem as much as reducing harmonic frequency. Bearings wore out faster and rods snapped, and engines became bombs.

 

Here's an article I had here:

 

With various aftermarket manufacturers claiming up to 15 horsepower gains with their underdrive pulleys, we set out to the dyno to find out how much power WE could expect on our 1999 ITA-prepped Saturn twin-cam powerplant. The results might surprise you, but here they are.

 

Because there were no pulleys available at the time, we went to the extreme and actually REMOVED the accessory drive belt (only for one run, of course) to see what the impact would be to ZERO drag due to the accessory drive – sort of pulleys with infinitely small diameters. We figured that if we saw a big gain without a belt, that the pulley gains would be somewhere inbetween, right?

 

We fired up the dyno and low and behold, removing the belt netted a whopping 3 HP (and we’re rounding UP). That's it. The number was repeatable, and even correlated to data run earlier on the doomed BMW motors - they saw similar results in their application.

 

So, in light of the fact that 3 HP was completely without a belt, we estimated that the best we could do was to underdrive a few components by 20% - or a theoretical 0.6 HP gain (3 HP x 0.2). After that, it hardly seemed worth it to try to custom fabricate pulleys for less than a 1 HP gain.

 

I know, I know – stock pulleys, like stock suspension bushings, aren’t sexy, and you can’t brag about them in the pits…but in racing horsepower talks and marketing BS walks. We chalked up this exercise as yet another learning experience in the quest for REAL horsepower. Maybe someday we’ll find some.

 

Case in point: last season our engine builder was experimenting with alternate crank pulleys on BMW engines. Like the other BMW teams (6 or so) in the series, they all elected to run these pulleys on a given race weekend. Anyway, 4 of the 6 cars went home that weekend on the trailer with broken cranks. Tell you something?

 

Another perspective is that auto manufacturers such as Saturn are always trying to squeeze the last 1/10 of a MPG from their vehicle’s fuel economy estimates. Big dollars and big engineering budgets are dedicated to this task, and you can bet that if any component could be underdriven further (a potential plus for fuel economy) and still meet its performance and durability bogeys, it would have been already.

 

Personally, I'd rather lighten the flywheel. Great for a manual...I don't know about an automatic.

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