lightweight flywheel good or bad?
 

So I was looking at upgrading my clutch and flywheel, however after talking to my stepdad who has raced for 25 years. He has only raced V8's though so a smaller engine might be different?? I was told that a lightweight flywheel will cause you to lose torque. I was a little curious so I did a little research online and found conflicting info on this subject. I was hoping that someone could shed a little light on this before I purchase anything. Also if anyone has one let me know how it feels performance wise. This is my first import car so im not sure how to tune these, sorry for the newb question. I come from a mustang background.

It'll rev up faster, but it'll be a little trickier to launch. It definitely makes the engine feel more responsive. If you're already in there doing a clutch, spring for the flywheel. Expect more noise.

i think the stock flywheel is light enough for street use.

light flywheels are kind of a hassle to do congested traffic as it requires more rpm and/or longer slip.

I love my lightweight flywheel, but this is absolutely correct. It's a trade-off. Responsiveness vs. driveability.

I also love my lightened flywheel. It's 22lbs compared to the heavy 31lb oem. I haven't noticed any difficulty with drivability or anything, just a tiny bit more chatter when your stopped in neutral.

Does srm get affected by the lighter flywheel?

LW flywheels do not casue you to loose TQ, they just require you to keep the revs up, to stay in your required power band. As others have said, LW flywheels will rev faster, but they also drop revs a lot faster than normal FWs. If it was me, I would go with a good chromoly flywheel over an aluminum one.

Nope, none at all.

I haven't noticed any issues with SRM and my flywheel.

:tup:

I had light weight flywheel with a street strip clutch on my old car. It would rev like a two stroke dirt bike with that light flywheel. It was alot of fun to drive hard but around town not so much, stop and go traffic had me swearing after a few minutes.

yah, my buddy had a RX7 with a lightweight flywheel. he let me drive it. it was a chore getting that thing going in traffic especially up a long hill. heel & toe start each time.

I had a lw flywheel on my 2 previous cars, one a 9lb and the other a 13lb... the 9 lb was a pain when I first got it but I got used to it... anything heavier than that is easy now. Once you get used to it, it's no big deal.

In a nutshell without going into detail, the Z gets so much chatter because stock it's not a "single mass flywheel." So when you go to an aftermarket lw single mass, it throws everything off a bit and will make some chatter.

From what I've read, the following flywheel is the best way to shave off some rotational mass lbs and get your revs up quicker, without sacrificing too much Drivability, and out of all the flywheels, has the least amount of chatter, if any at all. Some people get a small amount of chatter with it, some get none. This is the flywheel I plan on going with.

ZSpeed Performance South Bend Clutch DXD Black Nissan Infiniti Flywheel

That is the flywheel I have :tup:. Revs up quick, easy to drive, just a tad bit more chatter than oem. Zspeed's website has it listed at 24lbs, but they are actually 22lbs. According to Joe@Zspeed they are a bit lighter now since posted on the website and I weighed mine to confirm.

In my other car it is 7.5lbs paired with a stg4 unsprung. I DD it. No problems here.

I think that this is the flywheel that i'm going to get. It has all the good qualities of a lightweight flywheel and the driveability seems to be better than the other ones ive seen. Ive also been looking for a decent clutch, dont need a 1000 dollar clutch I dont launch to often but do go to the track once every couple of months. was wondering what everyone has and if this is a good stage 1 replacement? Im not cheap but dont need the top shelf products either.
Competition Clutch 6073-2400 Stage 1 - Gravity Series 2400 Clutch Kit

unless you're a special, it's not anymore difficult to drive, launch, etc your Z with a lightweight flywheel. great mod, wakes up the car so to speak.

for the record I have a 16lb jwt flywheel on my Z for the past 2+ years, 20k+ miles

Lightweight flywheels are great mods that provide better engine response and keep your engine revving in the power band. They're a bit loud when idling though. Totally worth it.

Srm?
 

I looked up SRM: Standard Reluctance Motor (that was a joke btw). Is that what you guys are talking about?

I'm thinkin maybe not...

Below:
Thanks Drex: Ya the SRM does react pretty quickly, but is a good question to ask.


Also, someone asked about torque and a lighter flywheel. Starting from a stop will be slightly less torque from drivetrain (less inertia from flywheel to help you get rolling and slightly more torque (to drive shaft) when accelerating (less inertia to spin up). I've always thought the flywheel felt too massive in this car. I guess they wanted it to be easier for mommy to get it rolling.

SRM = SynchroRev Match

I just looked this up and it reads 19lb:

ZSpeed Performance South Bend Clutch DXD Black Nissan Infiniti Flywheel

Yep, I bought mine a couple years ago and it weighed in at 22lbs, but listed on their website at 24lbs. Joe from Zspeed told me that they have been working on trying to shed even more weight from these. I guess they've succeeded.

I'm going with Specialty Z clutch/flywheel combo as next mod.

Wana get the wheels/tires done before or after... but those two are at top of the list.

Flywheel install
 

Don't know if I wanna put the flywheel in myself. How much does a shop typically charge to do that?

I'd say $500 is a good estimate.

I wouldn't consider the install to be too difficult. The only place I ran into issues was putting the trans back on the car. It didn't want to just slide into place, like I had read. I had to get it as close as I could and then pull it in with the bolts.

It is a tedious install though. Removing the shifter and wiring harness before even being able to pull the trans just adds to the workload. Plus, the bolts can be hard to access.

Thanks Aszyd, good to know.