1) "What are lightweight crank pulleys?"
Alutec lightweight crank pulleys are stock diameter (O.E size) crank pulleys, utilizing the original belt layout. The section that drives the alternator is the same diameter as the OEM crank pulley, hence no underdriving. Alutec crank pulleys are designed to maintain alternator output at exactly stock output levels so car owners with big stereos need not worry about flat batteries or weak charging capabilities. Constructed out of aerospace grade 7075 aluminum, these crank pulleys weigh between 650 to 850gms on average as compared to heavy O.E units ! 7075 aerospace aluminum also outperforms conventional pulleys made of 6061 grade as they have higher tensile strength, are more durable & lighter. Through extensive weight savings, power gains of up to 10% can be seen on a NA car and even more than 10% on a forced-induction car, depending on individual car's set up. All Alutec crank pulleys come fully balanced and counter-weighted from factory, features ultra hard anodizing for superb wear resistance & strength and are one of the most cost-effective power upgrade in the market today. Instant linear power gains can be felt across the entire rpm range and power curve after upgrading to these crank pulleys. It's the simplest hassle-free direct bolt-on crank pulley type which is most recommended for daily street use.
2) "What is underdriving/underdrive or overdriving"
Underdriving/underdrive is slowing the speed of the accessories, or the driven component, from the original speed they were turned by the OEM crank pulley. Underdriving can be accomplished in two ways. First is by increasing the diameter of the accessory pulley/s. The problem with this method is that it increases the size of the accessory pulley/s which increases their weight. Weight reduction is the most important key to increasing engine performance and response. This method also eliminates the ability to underdrive the a/c, which is a tremendous robber of horsepower.
The second method, used by companies like Unorthodox Racing (USA), is by reducing the diameter of the main drive pulley or crank pulley. By using this method they can achieve the best ratio of size reduction, underdriving, and most importantly they can maximize the reduction of weight on the crank pulley where most of the weight savings can be seen. This reduction in weight reduces the moment of inertia allowing your engine to respond faster to throttle inputs and perform better at all RPM's.
Overdriving is increasing the speed of the accessories, or driven component (like a supercharger), from the original speed they were turned by the OEM crank pulley. This can be done or accomplished in two ways. First is by decreasing the diameter of the accessory pulley/s. The second method, used by Unorthodox Racing, is by increasing the diameter of the main drive pulley or crankshaft pulley. Overdriving can be used to either increase the boost output of a supercharger or to increase alternator output due to increased voltage demand from a large/competition stereo or auxiliary lighting system.
3) "How do lightened crank pulleys give me more power?"
Weight loss is the most critical factor in making, or more accurately, releasing Horsepower! Each pound of weight taken off the engines rotating assembly is worth approximately 2.7HP and the figure increases dramatically with forced induction, nitrous, VTEC and increased RPM's. There are no adverse effects from using any of these pulleys. Bolt them on and forget about them, then just follow your vehicles normal maintenance schedule. For the daily driver who wants to ensure regular maximum driving pleasure with big stereos or other electronic gadgets, Alutec crank pulleys are strongly recommended for daily street use.
4) "Is my crank pulley a harmonic/torsional/vibration damper or a harmonic balancer?"
People are getting their crank pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term 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 we offer utilize a counterweight as part of the pulley as these engines are internally balanced.
The pulleys on most of the new import and smaller JDM 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. This is not to say that with our 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 our pulleys will notice the engine actually feels smoother. This is a natural result of replacing the heavy steel crank pulley with a CNC-machined aerospace 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.
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. We hope that after reading this you will understand the crank pulleys better.
5) "Will these pulleys cause premature engine bearing wear?"
This is a fear many prospective owners have and is a valid concern since we are dealing directly with the rotating assembly. Fortunately it is another urban myth 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 stress loads on your engine, extending 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 power outputs beyond 3, 4, even 5+ times the stock power levels.
6) "Are these pulleys hard to install?"
An installation done by a professional mechanic should take no longer than one (1) hour for crank pulleys.
7) "Do I have to change my belts when I install the pulley?"
For Alutec crank pulleys, most applications do not require a belt change as they’re O.E sized. When the belt sizes need to be changed, it is usually because the pulleys are either smaller or larger than the factory pulleys. The belt/s you will need are available from your local auto store or garage. Most qualified mechanics also include a belt change in the installation work.
8) "Does the anodized coating wear away?"
The anodizing on these crank pulleys are ultra hard to withstand long-term friction, ensuring durability. 7075-T6 aerospace aluminum has phenomenal weathering ability that allows it to remain beautiful even in the most severe weather environments, outperforming 6061 grade in this aspect. The anodizing color may wear away on the belt sections where the belts ride on the pulleys over time. There is absolutely no cause for alarm.
9) "Can the anodizing cause the belts to slip?"
No. Even without the anodizing, the belts have the same grip that they do with the stock pulleys.
10) "Is there any long term maintenance required with the pulleys?"
The only maintenance required is to check and replace the respective belts at the manufacturer's specified intervals. Other than this you basically bolt on the crank pulleys and forget about them.
11) "Will my engine RPM's change?"
The pulleys have nothing to do with the transmission and the gear ratios. The pulleys only change the speed of the accessories and nothing else. The transmission and the differential, as well as tire size, control engine RPM at any given speed.
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