[OneFastLotus]

Im wondering how much difference a lightened flywheel would make for our little cars?

 

[icyjaws]

guys say they have noticed a diff on the celica which is like 5-600lbs+ so i think the difference on the elise would be more noticalbe.

 

[James A]

I went from the standard 22 pound flywheel in my Seven to an 8 pound flywheel. Let me tell you it is a HUGE difference in autocross and fun factor. The car revs much quicker, it's amazing how much HP it takes to wind up a 22 pound flywheel. It really changes the whole feel of the car especially in something like autocross. One draw back, with so little enertia in the flywheel you really need to get used to the clutch again as the car will tend the chug away, jerk back and forth, on cold take offs. You get used to it and will know how to get away smoothly. It's a lot of fun to watch someone try it for the first time!
I am a convert and will definately go with a light weight flywheel when the LSD goes in!

 

[OneFastLotus]

Yeah I have 7lb Fidanza flywheels in my miatas along with pucked clutches, a fun combination...its funny to let friends try and drive the cars.

 

[frayed]

I dropped about 15lbs off the fly/clutch assembly on my 3200lb M3. It made a noticable difference. To me, the biggest benefit was easier heel toe shifting around the rack.

Does anybody know how much the stock fly weighs? Also, anybody check up on the Celica guys to see there are any NVH complaints?

On M3s, there is a noticable, though not objectionable, increase in NVH including tranny rattle at idle and some rawness to the engine as you go up through the rpm band.

 

[icyjaws]

not 100% but i think its a rather light 16lbs stock.

 

[jdl8r]

How many of you know the weight of the stock flywheel?

 

[brentil]

I've been reading these forums for a good while now, but thought I'd finally post. I haven't been overly interested in the normal discusion area, but these mechanical topics really interest me.

I went looking for the weight of the stock Celica GT-S flywheel for several hours, but I so far have been unsucessful. My guess is somewhere from 15 - 25 lbs [6.82 - 11.36 Kg].

I have found plenty of data on lightened flywheels for that car though. I've found the lightened ones weigh in from 7.5 to 8.5 lbs [3.41 - 3.86 Kg].

That's a decent rotational inertia decrease. It's already a light flywheel compared to other high torque/hp engines I bet, but at the rate this engine rotates you'll probably see a better response from a lighter flywheel then you will on an engine with a much lower RPM #. And also a greater response then the Celica GT-S too since the stock Elise engine's RPMs are slightly higher.

I'm going to keep looking for the value to see if I can find it. I think the math to show the differences between the GT-S and Elise with stock and lightened flywheels would be very interesting.

 

[brentil]

Ok, after spending 2 days using google to no prevail I switched over to altavista.com and got my answer on the first search

1. Stock GTS (chromolly) - 13.0 lbs. - 5.897 Kg
2. Blitz Active Clutch (chromolly) - 10.5 lbs. - 4.763 Kg
3. Toda (chromolly) - 10.3617 lbs. - 4.700 Kg
4. C-One (chromolly) - 9.9208 lbs. - 4.500 Kg
5. JUN (chromolly) - 9.6998 lbs. - 4.400 Kg
6. TRD Japan Flywheel (chromolly) - 9.6 lbs. - 4.354 Kg
7. RPS Billet (aluminum) - 9 lbs. - 4.082 Kg
8. TOM's (chromolly) - 8.03 lbs. - 3.642 Kg
9. AASCO (aluminum) - 8 lbs. - 3.629 Kg
10. Mueller (aluminum) - 8 lbs. - 3.629 Kg
11. Unorthodox (aluminum) - 8 lbs. - 3.629 Kg
12. Fidanza (aluminum) - 7.5 lbs. - 3.402 Kg
    [/list=a]
    
    I'll go back and do Kg conversions when I get a chance for our metric system using friends. Also when I get some time I'll try to do some math to show rotational inertia decrease values.
    
    Credit for these values goes to the NewCelica.org forums Click Here
    
    The 13.0 lbs sounds fairly accurate because from the official Toyota TRD Japan website they sell the TRD 1ZZ-FE flywheel (but not the 2ZZ-Ge for some reason), and they say that it is as follows...
    Weight: 4,500g (-38%) Moment of inertia: -55% *2 90910-02103
    
    Which is 9.92 lbs for the TRD which is 38% lighter, giving the stock flywheel 13.69 lbs on a GT, so saying the GTS stock is 13 lbs sounds realistic.
    
    (updated 05.02.2004 to add Kg weight).
    (updated 05.05.2004 to re-order values).

 

[MotorCade]

Good info, brentil. Is the 2zz-ge using its flywheel for damping the crankshaft oscillation? If not, (and I doubt it is) then changing the flywheel shouldn't add any NVH.

Cade

 

[brentil]

Ok, all I need now is the diameter or the radius of the flywheel. I found the clutch diameter (215mm), but not the flywheel so far.

Anyone out there have this info, or someplace I can find it? Most of these light weight ones are made in Japan, and their vendor pages are all in jap.

 

[OneFastLotus]

IMHO Fidanza is the way to go,I use Fidanza wheels in all my cars and have been VERY pleased. I had a JUN wheel in one of my cars when I purchased it. JUN wheels SUCK.

 

[LittleRocket]

I have the tom's in my built n/a 2zz spyder. It revs like a bike from 4k-9k. I did not run the stocker in it so I have no comparision to give in that regard,

 

[gotapex]

Is there a practical strength difference between the aluminum and chromolly ones? Should that be a factor for consideration?

 

[LittleRocket]

Molly is much stronger than aluminium. It runs about a hundred more though.

I have heard of aluminium units failing on other motors but never a molly one. I have yet to hear of a failure on the zz series engines either...........

 

[OneFastLotus]

I dont think we'll be needing a scattersheild for the Elise.

I have aluminum units, and I trust them for the most part. Im running 4X the stock horsepower through mine, so far I still have my lower legs.

 

[Ara]

13 pounds is fairly light for a stock flywheel. I would not expect a big difference from going down 5 pounds or so, maybe a little better throttle response. On some cars, a light flywheel shaves 15 pounds. Remember, there is a downside with easier breakaway exiting corners.

Ara

 

[brentil]

13 pounds is fairly light for a stock flywheel. I would not expect a big difference from going down 5 pounds or so, maybe a little better throttle response. On some cars, a light flywheel shaves 15 pounds. Remember, there is a downside with easier breakaway exiting corners.

Ara

Ahhh, but you're thinking of cars with large engines that max out at like 6500 RPM I bet. Thats where you usually see the heavy flywheels at stock. The 2ZZ-GE can reach 10,000 RPM I think (but is limited to 8500 with the Lotus ECU, and lower with the Toyotoa ECU). You're talking 141.66~ RPS compared to 108.33~ RPS. That's an extra 33 times per second the flywheel is completely rotated. Any weight savings at that speed will translate into faster acceleration of the flywheel.

 

[brentil]

Ok, I really hate this but I broke down and used the clutch diameter since I couldn't find the actually flywheel diameter. This will cause the end values to be off, but the data points will still curve the same for the most part.

1. KE Chart = data plot of various flywheels at various RPMs
2. I Chart = Moment of Inertia graph
3. Data = my rough data
   [/list=1]
   
   It's been a couple years since I had my last engineering class so I'm going to spend some more time looking up other formulas I can use to get some data from these #'s. Any suggestions would be great.