dreamspeed

iTrader: (1)

Just had a ACT Streetlite flywheel and a new Exedy OEM clutch installed.

Wanted to post up some comments about the flywheel and also give some details about the inevitable chatter.

Pros

1. My butt dyno says that there is a big increase in "pull" when flooring the throttle

2. There is a night and day difference in acceleration

3. Revs are much faster but not lightning quick. The stock flywheel had a split second lag before the needle even moved when i blipped the throttle. The after market flywheel revs pretty much instantaneously.

4. Dunno if this is exactly a "pro," depends on how you look at it i guess. Engine braking is lowered dramatically. With the stock flywheel if i ease off the throttle in first or sometimes second..there is large amounts of engine braking. With the aftermarket flywheel there is barely any noticeable engine braking or "drag"

Cons

CHATTER of course! It's inevitable and i would like to detail the chatter with this setup

For this review I will be using this scale

soft - probably can't hear it if you have an aftermarket exhaust or stereo turned up to a decent volume

med - can hear it even with exhaust or stereo but not very noticeable (a passenger that isn't looking for the noise might not hear it)

loud - pretty much obnoxious and very noticeable

RPM
500-1.5k - soft
1.5-2k - loud
2-3.5k - med
3.5-4k soft
4k+ - no chatter

Also, besides the actual "chatter"... there are also other whirling, thunking, scratching etc sound that you probably didn't have with the stock setup. All of these "white noise" sounds would be what i call "soft"

There's really no way to avoid these sounds but i've found that by readjusting your shifting/driving habits you can minimize how much noise you hear. Basically it's like a game of avoiding the "obnoxious zone" of 1.5-2k RPM.

I tend to up shift early and down shift sparingly...the perfect recipe for MAXIMUM chatter I've had to adjust my style to shift later and down shift more to avoid the 1.5-2k range. It's not bad if you are just accelerating through that range in 1st or 2nd...but if you are in that zone at a higher gear the chatter is more pronounced.

The time when the noise is the absolute worse is when you are accelerating in the obnoxious range under "high load." For example if you are in 3rd, 4th, 5th, 6th gear and you have to slow down....not enough to warrant down shifting but enough to drop you in the obnoxious range...and then you accelerate through that range...the chattering will be at it's worst.

Overall the chatter is either acceptable or completely intolerable depending on your own standards. Personally i think if you have an aftermarket exhaust...stereo turned up (not really loud but at a comfortable listening level) AND you change your driving/shifting habits a little... you can greatly minimize the annoyance of the chatter

jv350z

iTrader: (6)

thanks for this honest and insightful review.

winchman

I don't see how that's possible. You say you notice the difference when you "ease off the throttle". The engine is already up to speed, so any braking is the result of compression and friction. The momentum of the C/FW tends to keep the car moving.

If you now have a lighter clutch/flywheel, the deceleration you get when you ease off the throttle should be more, not less, because the lighter C/FW will have less momentum. Compression and friction haven't changed. Since the car is lighter, it's going to be easier to slow down, too.

In general, butt dynos aren't very reliable, but in this case I'd expect you're actually getting a little quicker acceleration of the engine and the car. The physics involved are in agreement on that score.

Why is any amount of clutch chatter acceptable, and why do you say it's inevitable?

bmccann101

iTrader: (16)

your comment ^^^ concerning the enginge NOT keeping itself driving easier due to less interia is fully correct... engine breaking will stop the car very fast w a lwfw, and it requires more constant gas pedal input during fwy drives.
the OPs experience of the opposite is surely largely in his head.
Just a heads up for those reading this as review..

pcressey

iTrader: (3)

Strange you have so much noticeable chatter... I just had the ACT HDSS Clutch Kit and Prolite Flywheel installed a few weeks ago, and I only notice it from launch to 2.5k; even then it is minimal.

350zion

iTrader: (58)

Don't care about the noise my clutch makes! Not that serious IMO!

srsairbags

subd

dreamspeed

iTrader: (1)

Of course the butt dyno is not very accurate and it could just be a placebo affect, but i'm experiencing what i'm experiencing so

About the engine braking...with the stock flywheel, let's say i'm going like 25mph in 1st gear, if i ease off the throttle the car kind of lurches and slows down. With the aftermarket flywheel if i ease off the throttle it doesn't slow down nearly as much. This change is very evident. Here is a thread discussing the same thing...there are also links to other threads inside that thread

https://my350z.com/forum/engine-and-...e-braking.html

I say the chatter is inevitable because it is. There is no way around it. There might be someone out there who is extremely lucky has has no chatter after installing an aftermarket flywheel but pretty much every post i've read has indicated that you will have some form of chatter after the install.

dreamspeed

iTrader: (1)

Every car is different i guess...and possibly your scale for "noticeable" chatter is different then mine. Some people are more sensitive to noise then others i guess.

djamps

iTrader: (1)

I had a 13 lb flywheel and had almost no chatter at idle. It was extremely noisy under 2krpm (for example taking a slow corner in 2nd or 3rd) but above 2.5k or so like stock. Engine of course rev'd quicker and it was easier to rev match on shifts, but other than that there was no difference on the dyno or at the track.

caaraa

Strange you have so much noticeable chatter.

winchman

Chatter is really hard on the rest of the drive train. It's like popping the clutch (or worse) dozens of times each time you start off. None of the components are made for that kind of abuse.

Z1 Performance

iTrader: (564)

what you are describing and what the OP are describing are 2 different things

the chatter that everyone speaks of is noise only, by virtue of the fact that there is no more dual mass, heavy flywheel masking the sounds...the transmission makes these sounds anyway, the flywheel determines whether or not you hear them. There is no physical chatter, or juttering

dreamspeed

iTrader: (1)

yah by chatter i mean gear lash or gear rattle. I know flywheel chatter is not really the correct term but I stated as such because it's the term most people are familiar with

http://www.uucmotorwerks.com/flywheel/gear_rattle.htm