i was just random searching ebay and found this. is this lighter? and will not harm the engine coz have harmonic damper?

http://cgi.ebay.com/ebaymotors/Nissa...spagenameZWDVW

 

interesting...

 

Last I knew, we dont have a harmonic balancer on the stock crank pulley anyway, correct me if i'm wrong...That was why it is safe to use a lightened crank pulley.

 

Here is the ATI webpage listing the dampner, spec. for the 350Z, note that there are two part numbers, one street, one race. The ebay sale does not list which it is that I can find. I am also having trouble with the listing stating JDM when ATI is in Maryland.

http://www.atiperformanceproducts.co.../damnissan.htm

I think this is comparable to the fluidamper listed here on summit that has been out for a while:

http://store.summitracing.com/partde...5&autoview=sku

 

Not exactly . . .

its got a harmonic dampener on the stock crank pulley.

the whole "safe" thing is at your discretion

 

Really? It looks like a regular pulley down there.

Chris

 

This claim never seems to be put to rset.. The oem crank pulley has a rubber type material to act as a silencer (prevent ringing) not as any type of harmonic damping.. The only damping it does is to dampen sound...

 

Not to sound like an ****, but sound is a harmonic and thus a vibration. Call it what ever you want, the fact is there is a rubber dampener on the pulley. The engine is internally balanced, everyone knows that, however that balance can still be compromised with vibrations acting upon it. There have been enough issues in my eyes to not be skeptical about it. There have been people that have had no issues what so ever and there have been people having to replace oil pumps and even engines citing the crank pulley as a culprit. I have nothing to gain or lose by stating my opinion, i just dont think being ignorant about the topic is the way to be.

 

A harmonic as used in acoustics is a multiple of the fundamental frequency of a sound..The use of the rubber on the crank pulley is to reduce , eleminate, dampen sound.. Not to be confused with an engine crankshaft harmonic balancer (also to reduce vibratory harmonics) which is used to reduce mechanical vibration, oscillations developed in the rotation of unbalanced mass.. The rubber on the crank does not dampen these vibrations...The damage reported was due to either improper install of the replacement crank or in the case of the KJR bad design. The keyway gap opened up and caused some excessive load on the crank transmitted thru seals and the crank..

 

oo crap...i just had the KJR put on. How many incidents are there of KJR pulleys failing??

 

Latest thread on the subject is about 2 weeks old .. Suggest you try search..

 

I do know that quite a few came up for sale after this became known.

 

I have seen industrial harmonic ballancer on pulleys, they look nothing like the stock pulley. If you have harmonics(vibrations) so strong as to cause issues, I don't see how that rubber will dampen them, it dampens the belt noise and minor pulley irregularities AT BEST. The quality of the stock pulley is very poor, I wouldn't be surprised if aftermarket pulleys are better ballanced than that, which is far more important than that rubber thingy. As a matter of fact, my friend had a nasty cranck seal leak and vibrations with the stock pulley on a 8000 miles engine. I am positive there have been has many problems with the stock pulley as with lightened pulleys.

I have 20K miles on my aftermarket UR pulley with no issues. Oil consumption is perfect, oil analysis perfect. (The few problems I have read about are all due to inproper intallation. (torque, tension, prying them out with a hammer, etc...)

 

 

The harmonic damper debate continues! First, its a damper. I have no idea what a dampener is, but it sounds like something that makes things wet. Second, everyone seems to offer various views on harmonics and damping, balancing etc.. The engine is internally balanced, but for everyone who says this over and over, do they even know what that means? The engine's reciprocating assembly is balanced to rotate without wobble, so it's "balanced". If there were no other forces acting on the crank then everything would be ok, but there are periodic surges of power occuring every combustion cycle, or two rotations. This induces a frequency on the crank. Because of the cycle taking two full revolutions, there are full order and half order frequencies. They are never identical as two combustion cycles can never be truly identical. The 60 degree V6 is only balanced for two of three primary harmonics. Flat 6, inline 6, and 90 degree V8 (unless using a flat plane crank) are groovy with all three major harmonics due to design. Ever wonder why inline 6's all tend to run smoother under throttle? Since our V6 is not as groovy, I would hesitate to remove the harmonic damper. It is there to alleviate the third order harmonics caused by the frequency of individual surges of torque applied to the crank. And while your engine may never have an isssue with the harmonics reaching the frequency needed to snap your crank, it can, and does happen. Even so, it is applying extra stress to the crank to have it removed. There is a massive thread that was started like three years ago on this subject and had info from all kinds of sources, and makes a good read. In reality, just search the SAE site for papers on harmonic dampers and download some, it'll give you the unbiased truth.
Will

 

Thank you Will for the information. Those that have installed the Fluidamper report it has provided some benefit in threads I have read.

 

From what I have seen there does not seem to be a large number of problems with aftermarket pullies that do not have dampners of some sort in them as long as the design otherwise is flawless. Example would be the key way stated above which would be the main flaw in a pulley. Not the dampner. If I am not mistaken, Preludes were plagued with blown engines due to this. Not Z's due to the internal harmonic balancer.

My opinion would be that it would be a good idea to have this type of dampner in one of two conditions:

-Supercharged
-High RPM Engine (i.e. 8000)

All though not necessary even then, I think that it could add some safety and reliability in those two instances.

 

What will the car feel if there is a harmonic imbalance. Vibrations at certain RPM? I get a rumbling consistently at around 2500 rpm. Initially I thought it just felt like alot of torque after my APS install but its clear now that its vibrations. Should I be worried? I thought maybe an engine dampener like the one from Stillen would solve the problem but after reading this thread, I'm wondering if its something else.
Dave

 

if you look at the new import tuner, they installed one of these on the project rsx build , im too lazy to look at my issue its their though so it has a significance