have not seen a thread that really talks about the differant flywheels, at least not all on the same thread. so i thought I would start one.


Racing beat states that stock is 16.8 pounds, and RXTuner said 17 ( I am sure they rounded up), so I have come to the conclussion that stock is 16.8 pounds


Stock
$0
16.8 pounds steel




ACT Streetlite
$325 includes counterweight (some places)
http://www.rx7store.net/product_p/streetliterx8.htm
13.9 pounds steel + 3.5 pound counterweight = 17.4 pounds



ACT Prolite
$ 360 includes counterweight (some places)
http://www.rx7store.net/product_p/proliterx8.htm
9.8 pounds steel + 3.5 pound counterweight = 13.3 pounds
more pics on post 43 https://www.rx8club.com/showpost.php...4&postcount=43

Video - http://videos.streetfire.net/video/e...71cee4ae60.htm



Fidanza
$ 390 requires counterweight purchace EDIT: check with your vendor, it seems some people get counter weight and bolts with theirs.
http://www.good-win-racing.com/mazda...15R-1003B.html
8.5 pounds alum + 3.5 pound counterweight = 12 pounds




Racing Beat
$455 includes counterweight and bolts
http://www.rx7store.net/product_p/rbflywheelrx8.htm
or
http://www.Racingbeat.com
12 pounds alum including counterweight

Video - http://www.youtube.com/watch?v=w5OrO_E56tw#GU5U2spHI_4 - Thanks California syle



Mazdaspeed
$480 Includes counterweight
15.2 pounds including counterweight




SR motorsports
$ 425 requires counterweight purchace
http://www.shaneracing.com/RX8_Clutch_Flywheels.html
9.75 pounds alum and 11 pounds alum + 3.5 pound counterweight = 13.25 & 14.5




Unorthodox
$530 built in counter weight
http://www.modacar.com/products/Mazd...flywheels.html (bottom)
14 pounds including built in counter weight, alum



Exedy
$460
http://www.coximport.com/Merchant2/m...duct_code=ZF01
12 pounds steel
(need more info on t his one.)




Spec
$403 counter weight unknown
http://www.horsepowerfreaks.com/pric.../part/Aluminum
? pounds Alum



PLEASE keep in mind that not ALL of these flywhees come with a counter ballancer which would cost extra. some even require you to purchace special bolts. so make sure you do your homework if you are looking into getitng a flywleel. some of the cheaper flywheels are so cheap because the price is only counting the flywheel. example, the ACT flywheel can be found for about $280, but you still need to b uy a counter weight. SR you even have to buy the bolts.

counter weight ~ $130 ($80 from Pettit)
weighs about 3.5 pounds, with bolts 4.1 pounds

__________________________________________________ ______________

This is a post I put in the clutches thread. (someone was asking about flywheels and the counter balancers.

yes MOST flywheels NEED the counter weight.

Now to be more clear, because I know its not crystal clear on this thread. The counter weight on the stock flywheel (and Unorthodox) is built right into the flywheel. if you look at the flywheel you can see that they have added material to one side making it heavier on one side. when you put the flywheel on you will notice that it can only go on one way via the key. this balances out the entire engine rotating assembly.

now here is the part that is not always crystal clear, ALL other flywheel require you to install the counter weight FROM AN AUTOMATIC, the counter weight is what balances the engine, the new pretty flywheel that you buy from what ever company is self balanced, meaning it does not weigh more on one side then it does the other. this pretty new flywheel bolt to the counter weight. (the counter weight acts as an adapter as well)

There, I said it....

If you look at the pictures I have on the first post you will see the difference in the stock flywheel and the ACT. notice the ACT needs the counter weight / adapter.



now just for Sh&%s and giggles, the big nut on the end of the E-shaft (crank) that hold the flywheel (or counterweight) on is a 54 mm (also known as a 2 1/8") with an impact gun this nut comes off with no problem. (yes you can do it with a breaker bar and something to lock the flywheel in place so it does not rotate, but seriously, an impact is WAY easier!.... I cant emphasize WAY enough)

I hope this clears it all up.







__________________________________________________ _______________





this post is copied form post ~45, after installing my ACT Prolite


yeah it seems as though we all felt the same thing. we all noticed a differance in 1st and second. I noticed it run through a little faster. take off was NO harder then normal, spin down was much faster, and when you turn off the key the engine STOPS the split second you turn that key off.

all in all I am happy with it. I think I was expecting to much like everyone else. but we all need to remember that Mazda designed that car with a pretty light flywheel from factory as it was. the total weight drop was only 3.5 pounds. (mostly on the out side). most other cars drop triple that ammount when droping to a lighter flywheel, so yeah they are going to notice a bigger differance.




none the less, here is how i see it. $360 gets you:

pros-
noticable (to me) gain running through 1st and 2nd.
smoother broader pull through the gears
no more hesatation or "bog" after shifting
faster revs in nuetral (WOOOOOO)
much faster shutoff (WOOOOO)

cons-
little rougher idle
little harder to take off in 1st (and i mean a LITTLE)


(also keep in mind we all litterally driven only about 1 or 2 miles on this new flywheel, lets see if i have a bigger smile tomorrow after really getting a feel for it.)

the true test comes sunday when I get to see what it does on the track!

more on the results to come.....

 

fidanza is $319
and your forgetting the ACT prolite, and SR motorsports 9 & 11# flywheels

 

added... thanks!

 

Does the weight include the counterweight... as well as those prices?

 

No, none of the weights include counterweight, and the fidanza and the SR motorsports need ~ $150 counterweight & bolts.

Counterweight is about 3.5lbs.

 

weight does not include counter weight (that I know of) and read the bottom of the first post again for info on weather it is included or not.

 

anyone know what the weight is for the stock flywheel? I read 16 someplace, and SR says 20......

honestly I belive 20

 

i'm guessing you got the quote for the mazdaspeed flywheel from a local dealership. you can easily get it from other places for $480. just thought you should know

 

yeah I did know that. i didnt know what price I should put.... do you know if it comes with the counter weight at all?

 

Hmmm, Ill work on weighing the stock flywheel tomorrow for you guys!
If you guys need any flywheels, we have some 9.5 lb ones on for dirt cheap right now.

 

I have heard the weight of a flywheel dose not determine how it performs the balance is what makes the difference. So you could have a 16lb fly that performs like a 9 pound fly. due to where the weight is. can anbody back that up?

 

Yep

 

what is the price? make? come with counter weight?
thanks for getting the stock info...

 

Technically, no. You would have to re-write the laws of physics.

 

uhh. So you're saying if you had a 20 lbs hammer, and all of the weight of the hammer was in the end of the handle, it would have the same force as a hammer that also weighed 20 lbs, but the weight was in the head?

Of course it makes a difference. If the weight of the flywheel is around the edges, it will be harder to spin up and will spin longer than if the weight was near the center.

 

Makes sence to me.

 

Yes, The MS flywheel does come with the counter weight. It is included in the price and weight.

 

its moment of inertia that matters, not weight

The MS flywheel is heavier then the RB flywheel - but because the MS flyweel has so much material removed from the outer portions of it, it has the nearly the same moment of inertia so the performance gains will be nearly identical

 

^i second that.

 

I have no clue what your trying to say with that example.

Are you trying to say that there is only one efficent design for something?
-Because thats what I'm saying!

If you could(theoretically) make a 1000lb. flywheel that performed like a 8.5lb flywheel, then why? It's an exercise in futility. Thats what I'm saying!

But the fact of the matter is that unless the extra mass is at the infinite center of the rotating body, it is going to have an effect on the inertia. Physics 101. A totally efficiently made 16lb. flywheel can never be as efficent as a 8.5lb. flywheel, physics 101.

 

A moment of inertia comparison would be cool.. hook the flywheels up to the same electric motor and time how long it takes for each of them to reach operating speed for the motor. Weaker motor better of course for timing reasons so the motor doesn't hit operating speed in a tiny window for the range of flywheels.

 

good idea ranger
Im defintely in the flywheel market so the more info the better.....

I dont want anything too extreme tho, so was maybe thinking about the RB one.....

 

If you have 2 flywheels both of equal weight, the flywheel with most of it's weight closest to the center will be more effective. It will require less energy to get it turning. Text book example 2 figure skaters. They both weight the same. They both start to spin at the same rate one figure skater pulls their arms in moving their weight closer to their center. This causes them to go faster even though they are not putting more energy into spinning. That's becasue the weight closer to the axis takes less force to spin. This is why a well designed 14lb flywheel will be able to perform like a poorly designed 10lb fly wheel.

 

I wouldn't call it poorly designed... there are reasons for wanting the flywheel to weigh more or have more mass on the edges, including easier to drive (revs don't fall as fast), more torque, etc.

 

I have not had much time here to explain, but yeah, this one pretty much sums it up as I would explain it..... good job you get an A+