Dampers: Facts Not Fantasy

 
Much of the science behind dampers is based on theories in books, applied in a vacuum, not actual real world facts. Most people buy a damper because they herd they needed one or out of a fear of the unknown. The problem is people don't know why they do or don't need a damper. There is no mystery here, just cold hard facts based on real world use and need. So lets get started.

First what is a damper? The most basic definition comes from Websters, which says; a damper is a dulling or deadening influence. Now that's pretty simplistic but its a great start. A damper is designed to absorb motion and frequency (harmonics) created by the crankshaft and the rotating assembly (rods, cams, etc). The most important aspect/element of a damper is how it's mounted to the crankshaft. A damper must be interference fit to the crankshaft snout. This means the damper must be heated up to be pressed onto the crankshaft snout, making a fit so tight its like the parts were made from one piece of metal. Without being interference fit a damper cannot function according to the most basic law of physics, "every action must have an equal and opposite reaction." Without interference fit a damper moves on the crankshaft snout and loses all of its ability to counteract crankshaft torsional movement.

The purpose of a damper is to protect the crankshaft from cracking due to excessive torsional movement and harmonic frequencies. A damper has no effect on bearing wear, it is the engines balance and build tolerances that control bearing wear. Dampers are not necessary in most modern engines because of the many advances in engine design but more importantly the quality of the materials and machining tolerances. Factors such as shorter stroke lengths, short piston TDC dwell time, no piston pin off-sets, forged crankshafts and engines that are balanced to blue printing specs or better (Honda engines are 0 gram balanced). Another important factor is the actual tune of the engine, especially when modified. Poor tuning leads to detonation which is an engine killer and no damper can stop this damage.

Now that these important facts are out in the open you need to figure out if your engine does or doesn't need a damper. If your factory crank pulley is not interference fit onto the crankshaft you do not need a damper. A great example of this is the 4G63 engine (1990+ Eclipse, Evo, Laser & Taon) which has its crank pulley mounted to the engine with four small M8 bolts. The 420A SOHC/DOHC crank pulley (Chrysler Neon, etc.) is interference fit but not because it needs a damper but because there is no key or dowel pin to hold the pulley from spinning on the crankshaft. Still confused? If you unbolt your crank pulley and it slides off the crankshaft you do not need a damper. There are a few engines where the crank pulley is sometimes slightly tight (VG30DE & DETT) but these engine also do not need a damper.

Now lets cover some damper terminology mis-understandings. The term "Harmonic Balancer" is often used but is incorrect. This type of device does not exist but was created by putting two terms together. The words are harmonic damper and engine balancer. A harmonic damper is just a fancy name for a damper. The term engine balancer is for engines that are externally balanced and have a counterweight cast into or bolted to the crank pulley or damper. The proper way to describe the incorrect term above is Harmonic Damper or Damper with or without external balance weight.


Now many people will still have lingering confusion even after all the facts above. This is ok as we are changing people's understanding through real facts not urban myths and legends that have persisted for too long. As discussed above many of the pulleys on import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley making them look similar to a damper. The elastomer in the OEM pulley serves as an isolator, suppressing noise from the engine accessories; the A/C compressor, P/S pump, and alternator. This noise is what car manufacturers call NVH (Noise Vibration & Harshness) which they want to keep out of the passenger compartment. Its the same reason OEM's use of dual mass flywheels to quiet transmission noise and freewheeling alternator pulleys to quiet even more alternator noise.

Many earlier generation crank pulleys on domestic & import engines have no rubber at all. We have samples of many of these from Acura/Honda B & D Series engines, 2.4L Altima, 1.8L Eclipse, 2.3L Fords, 2.2L Chrysler's, and 1.8L VW's just to mention a few. Some people will now worry that because we remove the NVH damper they will start to hear more engine accessory noise. The type and amount of NVH is unique to every car. As an example NVH will increase with aftermarket intakes or exhausts. OEM intake and exhaust systems use baffles and resonators to quiet intake and exhaust noise. Aftermarket systems eliminate these baffles and resonators to increase HP but they also increase noise from the throttle opening and from the additional size of the freer flowing exhaust. To most people the increase of in NVH makes for a sportier driving experience not to mention more HP.

For engines that need dampers UR will finally be offering the most innovative new damper technology in 20 years. The Ultra Damper will be in a class by itself offering unmatched damping capability from idle to redline. Even more amazing is the Ultra Damper will be ligther than the factory damper and any other damper currently available. Once again UR is leading the industry in advanced light weight solutions helping increase engine efficiency, saving you the consumer money on fuel and maintenance costs.
 
 
To make a proper choice of damper for your engine we need to analyze the different designs, how they work and the materials they use to do the damping. Once we go through the details it will be easy to see why the Ultra Damper has set the bar in modern engine damping. So let's get started!

There are a number of different types of dampers used. First is the most used type which all the OEM car manufacturers use. This damper is made of two parts, first is the inner section which mounts to the crankshaft and the second outer section (with or without belt grooves or teeth). These two sections are bonded together with rubber creating what looks like a rubber ring. This type of damper is limited in its ability to reduce torsional movement or harmonic frequencies because it has limited motion, uses rubber which causes wild swings in its limited effectiveness due to temperature and lastly the small amount of weight (the outer section). The first problem with the OEM damper is its lack of motion. It moves torsionally, side to side, but is limited in how far it can move due to the thin layer of rubber that bonds its sections together. It has no ability to move with engine thrust and it has no orbital ability. The second problem is the rubber which softens very quickly as the engine heats up. This softening radically changes the dampers ability to control torsional movement and harmonic frequencies. So ultimately this rubber causes the damper to only be useful in a very narrow rpm band. Rubber also degrades very quickly and causes OEM dampers to break apart at the bonding. The thrid problem is weight because with the OEM dampers limited motion it needs significantlyh more weight to function and the OEM's do not include enough weight to help counteract the other two short comings. The only positives of this type of damper are its cheap developemnt and manufacturing cost and its good ability to respond quickly to crankmovement due to the inertia weight being on the outside of the elastomer, this unfotunately is quickly negated by its lack of weight and the variability of the rubber itself.

The next type of damper is the friction damper. The friction damper is usually made with split intertia weights that have a friction bonded to them or to the hosuing they sit in. The inertia weights also have springs between them to force them into contact with the friction material. The intertia weights then ride on a phenolic or other type of dry or wet bearing. The amount of spring determines the amount of damping capability and the tune of the damper, meaning where it works best in the rpm range. The problem with friction dampers is they are complicated and very hard to tune, the have no thrust or orbital capability, since they use friction material to dampen torsionals they start to wear out from the minute they are installed and lastly the inertia weight is held captive by the friction material. Friction dampers have alot of parts from 20-30 bolts, 5-10 springs, two or more intertia weights, friction material, bonding agents, mutliple housing components plus bearings. Friction dampers are a disaster waiting to happen becaus of their complexity and sheer number of components. The moto should be keep it simple stupid (KISS) as the engine is already complex enough. Due to their tight fit inside the damper housing they cannot move forward or backward from thrust motions and nor can they move orbitally. Worst of all is friction dampers wear out. Even if this monster of complexity is assembled properly it will begin to lose effectiveness very quickly as the friction material begines wearing away from the second it is run. The inertia weight can only move when the friction lets it go, for a damper to work best its inertia weight must control the elastomer.

The next type of damper is the fluid/gel type. This fluid/gel is a viscous non-foaming liquid. The liquid is injected into a housing that has a free intertia weight already installed. The fluid allows the inertia weight to move and counteract the torsional motion and the fluid helps absorb harmonic frequencies. Fluid dampers were originally designed for large diesel engines like in trains or boats. The problem with fluid dampers are the fluid itself, its limited inertia weight motion, its inability to handle higher RPM's, its lack of servicability and lastly the inertia weight is held captive by the fluid/gel. The first problem is the fluid itself thickens and binds over time causing the damper to lose all its effectiveness as the inertia weight can no longer move. The second problem again is its lack of inertia weight motion. Due to the close proximity of the inner housing and the inertia weight the fluid damper has no thrust or orbital damping ability. The third problem is the higher the RPM the more likely the fluid/gel will lock up the inertia weight in the housing eliminating its damping ability. This was not a problem for fluid/gel dampers in diesel applications as they rarely went beyond 3000 RPM. Most domestic street V8 engines also rarely saw really high revs above 5500-6000 RPM until the last 10-15 years. Only now with the advent of really high RPM applications are these problems becoming apparent in bearing wear and other areas of crank damper from the fluid damper acting like a weighted hammer when it locks up. Once they fail they are also not serviceable due to their being welded together. Throw it away and now you have to pay full price again. The inertia weight can only move when fluidgel lets it go, for a damper to work best its inertia weight must control the elastomer.

The next type of damper is the o-ring style. The o-ring style damper use o-rings which are mounted into slots cut in the intertia ring. The housings are then slide over the o-rings and inertia ring. The intertia ring id free to move slightly inside the housing due to the friction of the o-rings and the surface of the housing. The problems with o-ring damper are the continued use of rubber as the elastomer material, Its minimal amount of actual damping material (small o-rings), it limited ability to dampen thrust, its inability to move orbitally, a complex inspection /rebuild process requiring tools you need to purchase and lastly the inertia weight is held captive by the elastomer. The use of rubber in the o-ring style damper creates another wear situation as the friction between the o-rings and the housing are what determine the movement capability of the inertia ring. This friction causes the o-ring surfaces to wear out, this wear causes undesired movement of the intertia weight beyond its original design intention. Also the use of o-rings limits the amount of damping material which needs to be significantly increased. Due to the location of the o-rings this type of damper does have a very limited ability to dampen thrust motion but because of the tension from the rings on its outer diameter the motion is not nearly enough. The o-ring design also prohibits orbital motions due to the tightness of the inertia and o-rings to the housing. Due to the frictional nature of its design this unit must be rebuilt but determining when to rebuild it can be a nightmare due to the tools necessary to open the damper for inspection. The inertia weight can only move when the elastomer frcition lets it go, for a damper to work best its inertia weight must control the elastomer.

The last type of damper is the urethane ringed Ultra Damper. This damper is designed with a single inertia weight which has a large urethane ring mounted inside of it. The inertia weight controls the elastomer. The inertia weight and urethan ring then mount inside of two aluminum housing which are then bolted together. The completed hosuing then is bolted to a steel hub to complete the damper by using a moutning material that can be interference fit to the crankshaft. The Ultra Damper eliminates the shortcomings of all the other styles of damper. The part is not complex when compared to the friction damper, it has a hub two housings an intertia ring an elastomer ring and 16 bolts or various sizes. There is no need to tune an Ultra Damper as they work extremely efficiently from idle to whatever max RPM you may be running. The Ultra Damper uses no wear materials in order to damper. Because the elastomer is inside the inertia weight the inertia weight now controls all necessary movement maximizing the damping capabilities. By mounting the intertia weight over the elastomer and allowing area inside the hosuing the inertia weight can fully move in any direction, torsioanlly, laterally (thrust) and orbitally. The Ultra Damper is the first and only 3D damper working in all three fields over motion. By using a large urethane elastomer ring we can maximize the damping material (medium) allowing for never before seen torsioanl and harmonic absorbsion. The Ultra damper elastomer is 10-20 times more than any other damper. The Ultra Damper is also easy to inspect, requiring no special tools to be bought and can be done in just a few short minutes. Although we don't expect any need for servicing the Ultra Damper is completely field serviceable by the consumer and all components are available purchase.

So now you know how all types of dampers work, especially their shortcomings. With this understanding it is easy to see how we at UR saw a great opportunity to advance the capability of the damper. The development of the Ultra Damper ushers in a new era in engine dampability allowing for higher levels of power without the potential dangers the extra power can bring. So when only the best will do think Ultra Damper, the only 3D damper available.
 
 
As a reminder the facts provided in this blog only apply to Unorthodox Racing products, other parts may look or seem similar but we can assure you they are not.

 
Underdriving is one of the simplest but least understood performance modifications. We hope this blog lays out the facts in an easy to understand format and finally lays to rest the most common misconceptions.
 
Underdrive basically means to slow the speed of one pulley connnected to another pulley.
- The first method is from the drive pulley (the crank pulley or the pulley driving the other pulleys). In this method the drive pulley is made smaller, the same as the rear gears on a bicycle. As you move from the bigger gears to the smaller rear gears your cranking is slower.
 
- The second method is from the driven pulley (the alternator, power steering or water pump
pulleys). In this method the driven pulley is made larger, the same as the front gears on a
bicycle. As you move from the smaller to the bigger front gears your cranking is slower.
 
That's it folks, you are now an expert on how underdriving is and can be done!
 
How do these priciples apply to UR and how does the amount of underdrive designed into the part make a difference. UR does all the underdriving for its import applications from the crank pulley. So this means all our underdrive crank pulleys are smaller than the stock crank pulleys. The amount of underdrive, the smaller the crank pulley is made can have a major effect on the output of the accessories (alternator, power steering and water pump). Before we go too much deeper we need to explain that the car manufacturers tend to over spin or overdrive the accessories. This is called planned obsolesence so they can sell you parts as these items wear out. Now that you know this fact you understand why underdrive is an important part of many of our pulleys. Now back to crank pulley size. When UR develops a new application we start with a reduction based on our early years of testing. We test the prototype on the vehicle and we verify that accessory output/function is within factory specified levels. For the alternator output we check voltage with everything on in the car, even items that will never be on at the same time. This also includes simiulated volatge draw of up to a 600 watt RMS aftermarket stereo system or auxiliary lighting system. This means with UR pulleys you will have enough voltage, your car will not over heat, your a/c will still be cold and your power steering will give you all the boost you need. The percentage or amount or underdrive can vary from as little as 5% to as much as 20% depending on the amount the factory over spins the accessory.
 
A common mis-understood fact when it comes to voltage and electrical systems is the dimming that can occur in the dash, headlights and interior lights. Your vehicles electrical system is a 12 volt system but car manufacturers overcharge these systems to as high as 14.5 to 15 volts. This extra voltage is unnecessary for the lighting as it reduces bulb life and sometimes dramatically. As an example most people can attest to seeing a relatively new car with a tail light, turn signal or head light out. After the installation of a UR underdrive pulley it is possible you may notice a dimming at idle but realize its because your electrical system was over charged. Simply put instead of being at 14.5 to 15 volts you may now be at 13.5 to 14 volts which is perfectly fine. As we state dpreviously we specifially test each car to make sure we maintain factory acceptable outputs and function.

One side not for cars that have an aftermarket stereo system over 600 watts RMS, auxiliary lighting with a draw over 600 watts or you've added a supercharger. In these cases you need to use our stock diameter crank pulleys.
 
That's it folks now you are an expert on why UR underdrive pulleys are completely safe for use in your vehicle.
 
 
As a reminder the facts provided in these blogs only apply to Unorthodox Racing products, other parts may look similar but we can assure you they are not. You always get what you pay for in the end.
 
We hear from the following phrase from time to time, "a pulley is a pulley is a pulley." Oh if only it were that simple. The first problem with this assumption is of course that all pulleys are the same, the biggest problem with this statement is when someone buys a cheap knock-off or copy cat pulley and it fails the buyer thinks that all pulleys are bad. Boy have we herd our fair share of horror stories over the years from these poor customers, from parts not fitting properly, to vibrations, to parts breaking and even disintegrating. With a little re-education and encouragement these customers are now happy users of UR pulleys.
 
The reason other pulleys fail is due to simple structural weaknesses. Although we will admit pulleys are not particularly complex to design there are some basic fundamentals that company’s who dabble in pulleys always fail to follow. Cross section thickness is essential, especially the further out the centerline of the belt/s are from the mounting face. After years of testing and finite element analysis prior to coming to market in 1997 we established strict minimum thicknesses. These minimum thicknesses are also extremely important on big power cars because during spool up as enormous forces are put on the crank and other pulleys during rapid acceleration. Another key element in the design process is how additional weight reduction is done. After exhaustive testing we primarily use holes, the copy cats tend to put slots in their parts. The problem with slots is they concentrate all the stress on a few small areas which is a recipe for disaster as cracks will form causing eventual catastrophic failure. By using round lightening holes without slotting we can evenly spread our stress loads guaranteeing structural strength. Now we are certainly not saying slots can't be used but only in appropriate circumstances. We do use slots for a few accessory pulleys because they are smaller in diameter and most importantly the belt is at the center line of the pulleys mounting point assuring the necessary strength.
 
So next time you hear or read someone saying all pulleys are the same just smile, try and pass on a little education but if they won't have it then hopefully they will learn the second time around.
 
 
Here is a saying we love: "The bitterness of poor quality remains long after the happiness of a low price is forgotten!"

 
It couldn't be more true and many of you reading this have unfortunately found this out the hard way! We now in our early modding years in the 80's we fell for the gimmicks too!

 
Before we get started we want to make clear everything mentioned in this and future blogs pertains only to UR products. Other companies may make parts that look or seem similar to ours but rest assured they are not.
 
Can UR products seem expensive? Sure but when you realize what determines the price of quality products like ours you begin to appreciate their true value. First and foremost there are development costs which in our case started accumulating years before we even incorporated or even sold our first product. We spent close to $100,000.00 in man hours, equipment, software and materials. Then there are all the other costs before we opened our doors to sell in May of 1997. Incorporation, registering our name as a trademark, product liability costs (which none of our current knock-offs artists ever have), office insurance, web-site development costs, lease costs for our facility's, electric, water, gas, workers compensation, disability insurance, credit card processing. We haven't even paid any salaries yet, nor the matching social security payments for those salaries, payroll taxes, health insurance and 401k program. What it comes down to is we spend in excess of $50-75K just to open the door each year, not including salaries, depending on the size of our staff.
 
We've herd many numbers thrown out over the years by arm chair experts about what things should cost and what profit margins are. The best one we've herd, which was focused at our pulleys, was a 300% profit margin all said and done. If that was the case I would have been retired a long time ago! The fact is that profit margins are no where near that percentage unless of course you are a manufacturer in the clothing, jewelry, beauty, software or computers. I would like to how these arm chair blabber mouths even justify the filth they spew. I'm tired of the baseless, clueless crap that these jealous hate mongers throw out for other, unfortunately impressionable, younger clients to read and stew over. These younger clients don't have the experience to realize that these blabber mouths have no idea what they are talking about.
 
What's even worse is the copy cats try to convince you that there products are ok through marketing lies and propaganda. Our favorite lie, thrown out there specifically by a johnny Come Lately Subaru pulley vendor, is that underdrive pulleys are bad for your engine. There couldn't be anything further from the truth than this insidious marketing myth! We specifically test every vehicle we make an underdrive pulley for, no other vendor can claim this, to make sure that with everything turned on in the vehicle that voltage stays over 12 volts. This includes items you would never have on at the same time and it also includes having an additional draw of up to 600 watts RMS or an equivalent lighting or auxiliary electrical draw. Now what we will say is for those that have a need for electrical output above these levels or because of bolting on an aftermarket supercharger we do make stock diameter crank pulleys. As with the sport compact underdrive pulleys we were the first to bring these stock diameter pulleys to the market in 1999 for cars with these special needs. Our second favorite lie is that there pulleys are lighter than ours. We are at a minimum are a few ounces lighter to mostly pounds lighter than the competition. Don't believe the hype because weight reduction means more machining which means higher cost which is impossible at the prices the knock off artists charge.
 
What it comes down to in the end is if you can't currently afford to buy a quality brand don't go out and buy a cheap knock-off because you'll end up paying twice to do it right when you could have done it right the first time. Save your money and try to be patient which will save you a lot of hassle and aggravation in the long run. Also realize that in the case of our products, especially pulleys, that you are bolting a critical component to your engine. Our parts costs what they cost not only because of our overhead but because we take the time to design and make them them right which includes the right strength and most importantly the proper balance. No other brand can make these claims. UR has been making pulleys since 1996, we always keep our customers best interest first and we back that up with 5 year guarantee. So is it worth it to save a few bucks when compared to the thousands it will cost you to repair the damage inferior parts will cause your engine. Maybe the part won't cause any damage, maybe the engine can handle the inferior quality but is it worth the chance?