So are you experiencing these chattering noises or no? because a lot of people are definitely hearing the same thing. how reliable there intelligence, i don't know. I'm just trying to figure out if this is "normal" for this car or not. any feedback or suggestions would be greatly appreciated. "The chatter, it plagues me."

i guess smartbomb isn't that smart. jwt my ***. that **** chatters worse than a stock setup. by the way this site *****. anyone got real questions and want real answers go to THE370Z.COM, **** this useless dumb ****.

*Edited by KillerBee370

Sorry for not personally jumping to answer your questions immediately as you might desire, I am sure that you can forgive me for not being at my zoltan hotline post 24/7 to service your every whim. Thank you for the complements, I love being called a useless dumb shit, I will attempt to answer your question quickly and respectably. To give an exact answer I am waiting until I can actually experience the chattering noise in a 370Z. The MT we use doesn't do it yet. What you call clutch chatter is probably actually input shaft backlash noise but it be sure we would actually have to hear it.

It would not surprise me if the 370Z rattles because the 350Z does and the clutch, flywheel and transmission are basically identical in design. The chattering noise is probably the same issue as what the 350Z had, a harmonic caused due to the axial and radial play of the input shaft and the power impulses generated by the engine. It usually gets worse as the car gets hot due to the gear oil getting thinner with less damping effect and the aluminum case growing and the clearances getting larger. Earlier Z's don't do this as badly because they have an anti backlash mechanism on the input shaft, basically a thin sheetmetal gear that is preloaded in contact with the main gear by a bellview washer. The gear tooth count is slightly different than the main gear so the anti backlash gear spins at a slightly different speed than the main gear, preloading it to one side of the lash clearance to make it harder to rattle. This also acts like a friction damper that greatly reduces the rattling harmonic. The Z32 is the last Z to use this sort of feature.

Starting with the 350Z, Nissan did away with this part and instead went with a heavy dual mass flywheel with a sprung hub much like a diesel truck in an attempt to smooth out the NVH of the drivetrain. The heavy floating flywheel was better at damping out a broad spectrum of NVH. However it doesn't do too good of a job on low rpm rattle. The 350Z also suffered from clutch engagement chatter when it was first released. Nissan improved that over the life of the 350Z but never fully cured it or the low rpm chattering noise.

A JWT clutch uses a sprung hub clutch disc and a solid single mass lightweight aluminum flywheel. The harmonics of the system are completely different. Usually the clutch engagement chatter might get better as the JWT disc is pretty smooth and that chatter is of a lower frequency, but an input shaft rattle will get somewhat worse due to the input shaft/flywheel assembly now having a higher natural frequency.

Either way the rattle is harmless and has nothing to do with transmission integrity or service life. It is somewhat annoying but some people don't notice it or it bugs the crap out of other people. We didn't want to give any answers until we experienced more 370Z's and we test the JWT clutch and flywheel on our 370Z but due to your great personal impatience we have attempted to give the best objective answer with what evidence we have with some interpolation based on our 350Z experience. We have it but have been too busy to install the JWT 370Z clutch and flywheel yet but look for a full test on the JWT clutch and flywheel in our magazine in the next week or two.

Thank you for your intelligent questioning!

Posted By on 19 Jun 2009 05:37 AM
i guess smartbomb isn't that smart. jwt my nutsack. that shit chatters worse than a stock setup. by the way this site blows. anyone got real questions and want real answers go to THE370Z.COM, fuck this useless dumb shit.

Personal attacks will not be tolerated. Please keep your posts at least semi intelligent and on topic. We realize that you have many options on the web for forum browsing and you are free to spend your time as you see fit but if it's YouTube you are looking for with garbage responses like this, you are in the wrong place.

Play nice and keep this forum professional.

Finished testing the JWT clutch and flywheel today, wow 5-6 whp accross the board. The new clutch is buttery smooth, no judder. The light flywheel does have more input shaft rattle like we expected though.

For a full writeup on the aspects of the clutch and light flywheel check here.

http://www.370z.com/MagazineArticles/tabid/57/articleType/ArticleView/articleId/65/Testing-JWTs-Nissan-370Z-Ultra-Light-Flywheel.aspx