I was just out at the JWT site and saw tat they have a 14lb flywheel for our G35's (which they say is half the OEM flywheel weight). Anyone try one yet?

I'm not so car savvy, what are the benefits and/or drawbacks to such a modification?

"God, Schmod, I want my monkey man!!"
------
Craig Ramseur
G35C/BlkOb/Graphite/5AT/17"
PhxGold/Focal/AudioControlEQ/Basslink
Z-Xtreme Grounds/Z-Tube&PopCharger

 

You get more horsepower with a lighter flywheel. The engine has
less resistance (weight) to overcome (turn).

2003 Twilight Blue 5AT Sedan, sunroof,
Graphite Leather, splashguards,
12 wire Hyper-grounding kit,
350Z intake duct, Stillen Hi-Flow Airbox
Underbody rear diffusers, Drilled aluminum pedals

 

nismo has a flywheel that is a bit heavier, I think about 22lbs

 

On my other car I have a lightened stock flywheel I think its around 16lbs. My brother has the aluminum flywheel it weighs in at 13lbs. My car is a little easier on city driving but his seems to rev just a bit faster.

Anytime you can get rid of rotating mass its normally a good thing.

Lighter wheels, tires, brakes etc make for a faster car.

 

I had one installed with the UR pullies. There is a noticable positive difference. Acceleration is better and while I'm on the freeway, when I go to down shift for more speed, the car responds better than I imagined. I haven't had any problems with having to raise rpm's to shift from first or anything. Overall, I think it was a great purchase. I haven't had the car dyno'd yet, so I'm not sure of the horsepower increase. When I do dyno, I'll pass on the news.

<font color=blue>2003 Caribbean Blue Coupe
6MT Prem, Aero, Nav.</font color=blue>[img]/w3timages/icons/cool.gif[/img]

 

The drawback is that you don't want to go too light. The whole point of the flywheel is to maintain some inertia.. keep the engine spinning.. while you change gears and such, or just to provide enough momentum for the engine to spin through the next compression cycle. Too light, and the engine will drop it's revs way down too fast.

I have no idea, though, just how much is too much.

 

I think the general consensus is the Nismo flywheel is a good compromise between more performance but maintaining streetability. The JWT and the Tilton flywheel are a lot lighter than stock and are more for people who don't care or mind about the loss of streetability and are looking for all out performance.

04' G35S 6MT Ivory Pearl, Willow, Premium

 

It's a Great Upgrade, you won't mind the drivability after the first day, you just have to get use to it, that's all. I don't really see any downsides to the flywheel, and I'm all for it. The UR pulley is probably the better bang for the buck, but you be the judge of that.

Coz


www.czp.us

 

Wow, no one mentioned the drawback. The oem flywheel is a dual mass flywheel, which functions to quell second order vibrations at low revs. I was going to install the JWT flywheel when my tranny was warrantied. But doing reseach on my350Z.com I found lot's of post's that said this, (new JWT flywheel owner). I want quick revs, but I won't deal with the noise.

"OK, had it in for a couple of weeks now. No clutch chatter at all. 1st and 2nd gear go by much quicker. There is the noise below 2500 rpms. Best way I can describe the noise is that it sounds like you have a bunch of sand in your tranny. That was expected after reading the SCC article and realizing you lose the damping factor of the stock dual mass flywheel. The noise has lessened though over the 2 week period"

Same poster as above commenting further on the issue.
"You only get the noise at low RPM in 1st and 2nd gear. At higher RPMs, it actually feels smoother with much less shifter vibration and it feels smoother while cruising in top gear. The fact that it's more speed related than RPM related leaves me to believe that most of the noise is coming from the driveshaft vibrating slightly and not the engine. I am not worried about it one bit. As to how loud it is, if you have your fan half way up, you can't hear it."

And to the above, someone replied.
"i get this exact same sound with my NISMO flywheel."

And a owner with the JUN flywheel said this.
"Mine chatters at idle and then makes a sort of grinding sound from 1500-3000 rpm. Even the guys at Zeil motorsports say its normal due to the lack of dual mass! I wish it made no noise, though. It hasn't worsened in 4 months either. Maybe I should take it to Performance Nissan in California, since they won't hastle me about my mods."

And, in replying to concern's voiced about the noise and chatter, a poster had this to say.
"Also, in regards to the vibrations, I wouldn't worry about that too much. I asked the guys over at Intense Motorsport and they had informed me that the vibration happens because the flywheel is lighter and thinner; the stock flywheels actually acts as a dampener of sorts that prevents this rattling from occurring. Many Supra owners have the same problem with putting on the flywheels. Like I said, I've put about 4000 miles on the flywheel and have had no drivetrain problems."

Hey, I just found a post that's a cut and paste review of the JWT flywheel from SCC magizine. This will also cover how the mod is a improvement, what's better about it.

""Our final tweak for this month isn't directly related to handling balance,but rather to responsiveness and a bit of out-of-the-hole speed. In a quest for smooth,quiet drivetrains that are strong enough to take relentless abuse, nissan has adopted duel-mass flywheels on all (both) its new engines.
Big, strong gearboxes like the one in the 350Z tend to rattle and groan like a UPS truck at low rpm. The noise comes from torsional vibrations originating from the surge of individual power strokes. A dual-mass flywheel separates the crankshaft and clutch sides of the flywheel by a set of springs. Using the power of math, nissan engineers chose appropriate spring rates and flywheel mass to damp out these vibrations, making the gearbox smooth and quiet and eliminating complaints from those who would whine about funny noises.
Unfortunately, that math also shows nissan engineers the Z flywheel has to be 25.5 pounds to damp things properly. That doesn't seem overly heavy when a quick zing of the throttle unleashes 274 lb-ft of torque, but when we replaced that 25 pounds with 13 pounds of jim wolf aluminum flywheel, we were amazed what we had been missing."
"Free-revving in neutral is just silly now. The lighter flywheel frees horsepower once used for accelerating its 25 pounds. In high gears , the difference is negligible, but in first and second gear, where each mile per hour means many more revolutions of that 25-pound flywheel, the difference is surprising. Hard-driving fast shifts are now easier and smoother, but cruising around, revs actually drop so quickly between shifts that lazy gearwork makes you drive like a clutch monkey.
The gearbox does indeed make noises now. At idle and accelerating hard below 2000rpm, you would think something was wrong if you didn't know better, but since you put the flywheel in, you understand the noises. Above 2000 rpm, the gearbox is silent. The noise shouldn't translate into accelerated wear, by the way, it just sounds like it does.
Despite the reduced inertia, the Z is still easy to launch . you can still lug it at 500 rpm away from a stop. You can still accidentally start in third . Otherthan the noise, there is no downside, whatsoever.

Sorry, this turned out so long.





"All that's necessary for the forces of evil to win in the world is for enough good men to do nothing.”
Edmund Burke

G35 6mt

 

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Best way I can describe the noise is that it sounds like you have a bunch of sand in your tranny.

<hr></blockquote>

That's the way my tranny sounds now occasionally in 1st and second gears at low rpms...
Does that mean the springs on my dual mass are busted?
I guess I'll find out, I have an appointment for this monday to get a couple things fixed and have the tranny looked at. If I'm going to deal w/ the noise might as well get a lighter flywheel

 

As always, GSedan35 has done tons of research on this. I'm following this one closely because with a supercharger being able to get up into the higher RPMs quickly has an even bigger benefit than normal.

The chatter is something I'd like to quantify because I already have the constant whine of the supercharger... Would I even be able to hear the JWT flywheel?

--Steve