Pulley Size/Fitment: Z34 vs. R35

sloboi

Our stock pulleys actually do have SOME dampening characteristics. If you've ever seen a stock pulley, it has a rubber ring running the circumference of the bottom of the pulley. This ring will essentially absorb energies at a specific wavelength, lessening the effects of torsional vibration--however, as discussed many times before, some feel this little rubber ring is not sufficient for true dampening. IF IT WERE, companies like Fluidampr and ATI wouldn't exist...

7419sundat

Firing order, stroke, bore, crank length, combustion and most used operating Rpm ( many more im sure) determine how the engineers create these dampners. IF NOT those companies like ati and fluidampr could just make one end all be all dampner.

Jordo!

Hmm... I thought they'd custom make dampers if special ordered.

I think the stock part is probably desirable then -- the torsional vibrations associated with the GT-R motor may be different, so the dampening may be greater or lesser than needed for your application. In any case, lots of boosted Z34's are running the OEM damper without incident, so it should be fine.

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sloboi

Yeah...I mean...yes and no, right? Torsional vibration isn't magic. It's not like there are different TYPES of torsional vibration. The focus of the silicon/rubber is to absorb vibrational energies. The vibration is created by the turning of a weighted shaft between the two pivots. Assuming that the GT-R and 370Z have a similar weighted/length crankshaft, the vibrations would be similar at similar RPMs.

Torsional vibration isn't magic.

7419sundat

I forgot to mention magic...

sloboi

I was being sarcastic, but you see where I'm coming from. Combustion would have NOTHING to do with torsional vibration. Why mention it?

sloboi

PLUS, we've already established that the bore and stroke are VERY similar. I'm pretty sure the crankshaft itself is also almost identical in length. Weight would be the only factor--and EVEN THEN. Torsional vibration isn't magic lol.

7419sundat

seriously if there was no combustion we wouldn't need a dampner the rotating assembly would only need balanced. If you think it will be better then do it... no one is gonna pull any data to prove you otherwise. Actually you should call fluidampr or somebody and ask them questions about it.

sloboi

There are already not a lot of boosted 370Z's out there. Of those that are, a few have have had problems. Torsional vibration will rear its head in the failure of other components (the oil pump, apparently, a common one). If I can spend $600.00, and simply reduce the chances of my vehicle running out of lubrication when driving, that's $600.00 well spent.

I do thank you all for your opinions and advice. I'm just going a route no one's gone before. Could work. Could not. Trying to use my limited understanding of physics, and some logic to figure things out.

sloboi

I don't point things out just to be an ***; keep that in mind before judging me for my next comment.

If you are going to attempt to prove/disprove something, 7419, please use logic, and relevant information. YES, if there were no combustion, we wouldn't have this conversation. YES, if the glove didn't fit, Mr. OJ would have had a difficult time getting his hands in the glove. WHAT THE **** DOES IT MATTER to the question at hand?

christian370z

Very similar means they still have slight differences, and slight differences at 7,500rpm become much bigger differences.

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-320whp / 259wftlbs-
SP Rays -- RE-11s -- SpecialtyZ Tune -- Swift Springs -- Stillen 25R Oil Cooler -- Stillen G3 Intakes -- Berk HFCs -- F.I. 12" CBE -- Stillen Sway Bars -- Es14 Spring -- INGS+1 lip -- CF Spoiler -- GTR Start Button -- VLED Parking Lights -- PWJDM V2 shift knob

sloboi

I don't understand theses moot arguments. Are people running around with lightweight pulleys that have NO dampening? Yes. Are there people running their boosted 370Z's with the OEM pulley? Yes. I do not have a sophiscated understanding of the complete mechanics behind torsional vibration; do you? I will assume no. With that being said, my understanding of torsional vibration leads me to believe that dampening this kind of vibration will be fairly straightforward--you take something that will absorbe the energy, like a fluid or a "spring" type solid like rubber, and stick it on the thing you want to dampen. Do you have any logical reason to suggest otherwise? If not, stop posting. I'm not saying I have proof, but most of us understands how vibrations and dampening works, I hope.

There is NO WAY our OEM pulley will have better dampening characteristics than the ATI dampner, even if it's made for a GT-R. Have you seen the little rubber ring? Lol

Please, guys, if you're not here to help with the original question, and are going to attack my reasoning, at least come with facts and logic.

7419sundat

Ill try to help one last time. Every engine has a different frequency that the dampners is designed for. You need to figure out which one your trying. For instance if a race dampners was designed for 10000 rpm it probably wouldn't be good for your car. A daily driver one would obviously dampen at lower frequencies. Basically what if our engines need dampening at 3000 and redline and the dampners you chose didn't do that extreme vibrations could damage your engine especially the more power you have.

sloboi

Which...is the same RPM range as the GT-R...

christian370z

No one's attacking you, we are offering our view points. But since you seem to have your mind made up, go ahead and do it. Maybe it'll work, maybe it won't. No one's tried it so why don't you be a first?

__________________
-320whp / 259wftlbs-
SP Rays -- RE-11s -- SpecialtyZ Tune -- Swift Springs -- Stillen 25R Oil Cooler -- Stillen G3 Intakes -- Berk HFCs -- F.I. 12" CBE -- Stillen Sway Bars -- Es14 Spring -- INGS+1 lip -- CF Spoiler -- GTR Start Button -- VLED Parking Lights -- PWJDM V2 shift knob