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Old 05-31-2011, 09:37 AM   #19 (permalink)
jtsmith1
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Join Date: Apr 2011
Location: OH
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Drives: 2009 370z
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Quote:
Originally Posted by RCZ View Post
haha, yeah the car is "rough" pass 4500RPM. You're not going crazy. The way it sounds and the way it feels are two totally different things. No one should appreciate an engine that feels like you're breaking it when you take it up in the rev range...which ours does.

I don't think its that we're hitting its frequency, it just feels rough. It does it for several thousand RPM and that should tell us its not just resonance, its just that the damn thing vibrates a lot. Be it from the vvel system or more solid engine mounts or what. I've had three types of flywheel on my car and they all made similar vibration at high rpm. You could say the stock fw feels more muffled because it doesnt seem to get transferred into the cabin and chassis as much, but its still there loud and clear.

I had solid transmission mounts installed a while back and the vibration was completely unbearable. At high RPM it felt like the world was ending. I think the best we're going to be able to do is isolate the vibrations as much as we can, maybe we can get some liquid filled mounts like porsche does... that gt3 feels like silk at 9k rpm.
Right! I know its not resonance, if it was then the engine would literally tear itself apart. But as you approach resonance, vibrations increase until you reach resonance, then slowly decrease as you continue passed the resonance frequency.

I'm wondering if the engine is approaching this range, frequency wise, as its rpms are increasing.

Hydraulic mounts would be awesome, as long as they didn't leak, which all do over time.
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