Aftermarket pulley wobble with video
 

After I installed an aftermarket Raceseng crank pulley I noticed it wobble but when you give some gas it looks stable. I've uploaded a video. I did make sure to torque it to 94ftlb.

https://youtu.be/vfThzZX2FUk

I'd strongly suggest that you take that puppy off, put that pretty thing on a shelf in your garage, then put the OEM pulley back on .......:eyebulge:


humfrz

Im still surprised people still buy these things

Did you doible check the issue described here?

http://www.ft86club.com/forums/showthread.php?t=26386

Yeah. It was flush. I'm guessing this is not worth it.

+1 Lest we forget its function let's call it what it is; a harmonic damper.

Noted. I'll take it off. Hopefully the OEM won't start wobbling.

not on an internally balanced 4 cylinder it is not.

:popcorn:

Better yet get a fluidampr..

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killconey, here is some interesting reading for your Sunday pleasure.

http://www.onallcylinders.com/2015/1...and-balancers/

If the OEM pulley wobbles after you put it back on ...... I'd suggest you check your pulley changing procedure.


humfrz

Would you buy that the OEM crankshaft pulley is a "elastomer style harmonic balancer" ....??

If not, prepare for a :slap: down from ol @Ultramaroon ........:D


humfrz

Last time I got in a pulley debate (well last last last time) I got sent a bunch of links that we're inconclusive. I've had my lightweight crank pulley for 20k miles.

BTW, it's just me or it's not the CP that seems vibrating in video but one small pulley .. but most of dampener related remarks seem to be related to CP.

Oh no.

Meh, I'm waaaaay over this debate. People will do what they wish. I won't be buying their beat up engines so what do I care?

Good call, OP. Get a lightweight flywheel if you wish but if you want cool functional up front, @Somerandom18 is on point.

don't give a crap what anyone says. Subaru in its adds on its own website says the engine is internally balanced. Every i4 and boxer 4 cylinder engine is internally balanced. Harmonic balancer or whatever you wish to call it only are needed for larger engines and v6 or v8 engines because they are all compromised in some fashion.

Our engine is a boxer engine. You literally cannot get more balanced. My Yaris, which is a i4, has had an NST pulley set for 60,000 miles. My BRZ has a pulley set for almost 10,000 miles.

Our stock pulley's are crap. If I was going to add power I'd switch pulley's first thing. It is obvious they were made simply to last forever and not much else. Subaru's have a history of all sorts of idiotic issues that go back to their engineers compromising their engines in some way for the US market. If you really are worried about harmonics you need to go buy that fluidampr damper, hell it supposedly makes more power on a dyno as well.

So I've put the OEM pulley back on and there is no vibration. Must either the way I installed it the first time or the it was the fault of the aftermarket pulley. Either way I'll leave it alone since its working now.

Well, now @why? ....... you didn't address my question:

"Would you buy that the OEM crankshaft pulley is a "elastomer style harmonic balancer" ....??

Allow me to rephrase the question for you.

Would you agree that the OEM crankshaft pulley on a FR-S, is considered to be a "elastomer style harmonic balancer" ....??


humfrz

Damper not balancer.

There's a reason why the lightweight pullies lower horsepower..

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You lost me at "don't give a crap what anyone says"! I pushed through but then " Our stock pulley's are crap" took me by surprise. Like Mike Tyson you continued pounding with a left hook aka "If I was going to add power I'd switch pulley's first thing." and an almost perfect uppercut "It is obvious they were made simply to last forever and not much else."
And that is how I got KO by your strong "I bought it therefore it works" cognitive dissonance arguments!
Looks to me like you use "balanced engine" without even knowing what the harmonic balancer does. This is not a tomato/tomatoe case! Heck, a simple google will bring you this info: Every time the cylinders fire, torque is imparted to the crankshaft. The crankshaft deflects under this torque, which sets up vibrations when the torque is released. At certain engine speeds the torques imparted by the cylinders are in sync with the vibrations in the crankshaft, which results in a phenomenon called resonance. This resonance causes stress beyond what the crankshaft can withstand, resulting in crankshaft failure.
But wait ...there is more: To prevent this vibration, a harmonic balancer is attached to the front part of the crankshaft

So you see why no matter how "balanced" an engine is internally, if it requires a harmonic balancer (aka crank pulley damper, crankshaft damper, torsional damper, or vibration damper) and is being equipped with one from the factory by qualified engineers with years of experience, don't remove it! Especially if you rev this engine high enough to feel like you drive the car!
Hope it helps! :cheers:

no. It is a crappy hunk of metal made as cheaply as possible meant to last as long as possible and nothing else. This article really shows the issues. Basically if you drive the car normally you are never ever going to show any issues. What makes me laugh is that fluidampr actually increases vibrations above 5500 rpm over the stock, aka where a race vehicle will actually spend most of its time. Their so called "SFI" rating is done at 12,500 rpm, aka an rpm no known FA20 can actually ever hit. What this article tells you is harmonics don't exist at all for our cars. It is not something anyone has to ever worry about unless they are going to add lots power to their vehicles, and even then nothing they show actually says anything will ever actually happen. The only interesting thing is this shows that their dampr might add a couple hp, but every dyno operator will tell you that very well could be within the error factor of every dyno ever made. This article makes me even more confident anyone can do anything the hell they want with their pulley's and it isn't going to change anything that matters.

Man, do you even graph? LIke seriously. I take it you looked at the second chart, which actually shows the extent of the actual vibrations, hence they recommend to look at the smoothness of the damping capabilities.
"Second order comparison between the OEM tuned elastomer damper and Fluidampr performance damper. The dominant second order represents the firing order in four-cylinder, four stroke engines. Clear start and stop damping range spikes of the tuned elastomer damper are present at 3900 and 5250 rpm, or 130Hz to 175Hz, for a narrow operating range of only 45Hz. Note the smoothness of the Fluidampr damping capability through the same rpm range."
Also, the third and fourth graph actually shows "The Fluidampr performance damper was able to cut amplitude of the excited 3rd order vibration generated by the 260Hz crankshaft resonance in half, down to below .1 degrees peak." I dare ask, do you even know what that means? You know, different frequencies and grades of vibrations, etc. I am not by any means an engineer but i have a somewhat clue about the complexity of it.
If you really want it simplified, the fifth chart shows the extent of vibrations at different rpm.
Attachment 149447

Next time, when you challenge the findings of a professional test, please make sure you really know what you are talking about.
Also, please stop spreading wrong info. "What this article tells you is harmonics don't exist at all for our cars." Yeah it so does hey! Totally! Please read my previous post for educational purposes!

:burnrubber:

:slap: ....... how DARE you correct ME ....... I've already made up my mind and "don't give a crap what anyone says"! ......., to quote a recently self declared expert in the field of pulley things........:D

Seriously, I'm simple minded and just remembered this from what that guy Wiki had to say:

"A harmonic balancer (also called crank pulley damper, crankshaft damper, torsional damper, or vibration damper) is a device connected to the crankshaft of an engine to reduce torsional vibration and serves as a pulley for drive belts.[1]"

Is there a difference or are you just slapping around an old man for giggles ...??

:happyanim:


humfrz

Oh boy! :popcorn:

I'm pretty sure "balancer" versus "damper" is a semantic argument. Where "damper" is functionally accurate, "balancer" has been used way more and so we're stuck with it.

For instance, I gave up making the distinction between "motor" and "engine." Yes, I know in this application an engine is the motor but I still cringe a little on the inside whenever I hear it.

Yep, I hear that.

To me an "engine" is something you pour fuel into to make it run; a "motor" is something you plug in to make run ...... :D


humfrz

WOW!

For now, @why? , I'll just challenge the statement which is bolded above.

Are you saying that a boxer engine is more "balanced" than an in-line six ....??

:popcorn:


humfrz

THANK YOU! :bow::bow::bow:

No giggles, I learned to respect my elders...

On some engines the pulley plays a crucial role in balancing the whole thing.

On this engine it really is internally balanced, and the pulley itself is balanced (OK, I haven't verified this one, but the engineers say the engine is balanced internally, so I'm pretty sure it's like my previous car, which I did test... that pulley had the same rubber insert and people ran lightweight undamped underdrive pulleys hundreds of thousands of miles no problem...) So the only thing it can do is change how the crankshaft etc. sees harmonic resonance... Which it dampens. No balancing involved.

Pedantic, but if you're arguing its importance when we haven't seen clear failures as a result of pulleys,... I have no clue if it's good or bad. But I do know it's not balancing anything. :) I also haven't installed a lightweight pulley, though I have one somewhere...

C

Thanks for being gentle on an old man ..... ;)

Heck, I don't know if a dampened type pulley is necessary on this engine or not.

All I know is that my car has one ...... and it ain't broke ...... so, I'm not going to "fix" it ...... :)


humfrz

If the damper wasn't deemed necessary the OEM wouldn't have specified it. A stamped steel pulley is much cheaper to manufacture.

*sigh* Here we go again.
There's only one answer for this issue:

Attachment 149495

I refute that statement as a valid argument. Are you suggesting that everything on this car is "necessary". If I remove the radio is the car going to blow up? It would have been cheaper to omit the radio.

If you were serious you would've used a better example than the radio.

Maybe you should have stopped with the picture of the sexy girl ..... :D


humfrz

I don't think one in pic is still virgin girl :D

Would it really matter ...... ??

:happyanim:


humfrz

That's it. I'm emailing Subaru.


Done. If/when they reply I will post here and I will forward their email to those who want it.