I went ACT lightweight flywheel and 6 puck heavy duty clutch kit. overall I love the way it revs up quick. I did change my shifting techniques although not consciously at first. I double clutch just about all the time because aftermarket clutches are much harsher as they engage...oh and chatter, you'll learn to love it.

 

^Thanks guys for the interesting info. I've got the 3.9 fd and from what I gather I'd probably benefit best with a more mid-weight, high quality.

 

I've seen that most of you guys are N/A. What about for turbos? I heard a rumor that you want to run a heavier flywheel so your rpms won't drop so much when you shift so you don't have to build up boost as much. But then I think about it wouldn't it be ok because you should build up boost faster because your rpms go up quicker?

 

I have a lightened flywheel on my boosted Z. I've had it when I was N/A also and honestly I don't think it drops down any quicker. Plus I think my tune doesn't let my rpms drop down that fast.

 

^btw I have a Fidanza flywheel. I think it weighs like 16lbs? It was rackety before I had my idle raised lol

 

What year Z do you have? Mine is an 04 an if I remember correctly 2004s can't have their idle raised due to the throttle body it has.

 

Mines an 05. Ever since I've been boosted I haven't heard the racket anymore. Just the way the ProEfi is tuned I guess.

 

Also I might be wrong but I think I raised it slightly when I was NA with the Cobb Accessport...It's been a while though.

 

Glad I read this thread. A couple of questions...New clutch/flywheel going in the car. Disappointed I couldn't do it myself, but at 55, you don't lay under your car for 2 days when it's 20 degrees outside anymore. Here is the fidanza flywheel I'm looking at: http://www.zspeedperformance.com/Fid...eel-143351.htm.
It will be going in my '06 350z with no real mods. My questions revolve around the fact that it's my primary driver. I have a 1 hour commute each way to work...well, since I got the Z it's more of a game now, but I still travel an hour one way. The added mass of the OEM flywheel allows for longer coasting when you remove your foot from the gas. The lighter flywheel (14.5 pounds) allows for better gas mileage and quicker acceleration due to the obvious shedding of weight. I'm trying to decide if I should stay with a heavier flywheel for the long cruise (is it less wear and tear on the motor?), or go with the lighter one which should give me better gas mileage along with the performance pick-up. On the fence about this. I drive her hard at times (more often than not), so I know I will enjoy the enhanced acceleration. And one final thought, the gear chatter you're all talking about. I know that "loud" is a relative term, but how loud are we talking? Is it a whine, chatter, vibration? Will it drive me mad after an hour of it? Should I just turn up the stereo to "break the windows" and enjoy the ride. Any input is appreciated. Thanks, all.

 

I commute 50+ miles daily each way, so about 100+ miles a day.The FW chatter isnt louder than stock,at least for my setup.You shouldnt worry about it too much,I havent heard anyone say its plain unbearable.

 

Keep the OEM flywheel.

I prefer the lightest flywheel available, personally. When it comes to highway cruising (1 hour), the awkwardly heavy OEM flywheel is probably the reason the difference the city/highway mileage difference is so great. I get ~37mpg highway, 22.5 city. The 30lb flywheel allows for less throttle position at the same cruising speed.

If you were doing mostly city driving, I would suggest the opposite. That is where the mileage gains come.

 

Is everyone exaggerating MPG?


I can not break 24mpg in my 03 6sp with test pipes. I kept it at 70 or under, no harsh starts and 24.5 was the most I ever did. Now it just hovers around 22-23 with WOT here and there.
I did KnN filter, test pipes, spark plugs, oil changes and nothing.

As for your 37MPG, the ONLY time I got 37 MPG in my bone stock 99 Civic 5 speed was driving to Texas, under 70, and in 5th gear for ~200 miles. Couldnt even hit 40 mpg, but now people are doing it in Z's?

 

https://my350z.com/forum/engine-and-...th-review.html

This is my review of the jwt clutch/lightweight flywheel/ billet tran mount/wildwood slave

 

Great thread. I myself run 4.08s and the Z1 flywheel. I love the combination of the two. 1st and second gear is definitely tricky but other than this, it revs and accelerates extremely well for NA.

 

How is the chatter on the mild Z1 23lbs ?????

 

I have a lightweight FW as well and i love it! Unfortunately i couldnt tell you what brand because dumb dumb that had the car before me put a stage 3 clutch with a lightweight FW in it.

Does anyone have a Comp. Clutch Stage 1 clutch with a lightweight flywheel? Or how are everyone's thoughts on the Comp. Clutch's stage 1.

 

This is just plain wrong.

Inertia is the only benefit to a heavy flywheel, your engine revs won't decrease as fast when you depress the clutch and therefore your speed won't decrease as quickly when throttle position closes.

Point is, to keep your fly wheel rotating at whatever static rpm you're imagining requires the same force regardless of the weight of the flywheel. It's bringing the flywheel up to that speed or slowing it down to that speed that is effected. To maintain that speed the heavier flywheel is still going to require more but it's negligible when holding a cruising speed with no other variables. Welcome to the real world where there are other variables. Light flywheel means better economy. Right foot discipline and transmission manipulation are bringing your mpgs down whether on a long cruise or a city drive.



Didn't mean to resurrect an old *** thread but that couldn't be left as good information....

 

I'm gonna chime in as well even though it's an old post. All this stuff still shows up in Google searches. From my experience The lighter a flywheel is, the faster it spools up RPM; but also means the harder it is to start from a standstill. Which can go both ways in drag racing or road race or autocross. In my drag days I and my friends preferred billet steel/forged steel as we were driving higher powered street cars. A 6 or so pound flywheel isn't to street friendly. Hard to get used to and can make the clutch feel more aggressive. A light flywheel is great for autocross/road racing on downshifts. To each his own I guess but I would definitely match a flywheel with clutch/pressure plate and not just throw parts at the car like some young folks do. Everything has a pro and a con. I hated aluminum flywheels on daily driver street cars

 

I forgot about this one from '13! I ended up with a SB 19 lb. steel flywheel, SB stg. 2 clutch, Z speed/Willwood csc, master and after 3 yrs. or so I love this combo and highly recommend it.