# Another Flyhwheel Question

Discussion in 'General Tech and Maintenance' started by H22AdelSol, Mar 9, 2004.

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Ive searched on the subject and havent came up with my answer. My question is not which is the best flyhwheel it is what happens when you drive a flywheel that is 8lbs compared to 12lbs? People on here say if its mostly a street car dont go 8. I dont care about the comfort of the ride, im into the performance.

If my car is going to be stiff and uncomfortable with tein springs but handles really well i dont give a shit.

Anyways will I gain a lot more out of the lighter flywheel? I was lookin at XACT because they seem like a reputable company but only have 8.8lbs. Then I saw clutchmasters but ive seen there clutches and how they suck.
look here
I think I might go with this flywheel
KAITEN SUPER KARUI FLYWHEEL: PRELUDE 92-02
So if anyone has any comments, pls post. thanks

2. ### CRX-YEMSuper ModeratorModeratorVIP

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with a lightened flywheel the moment of inertia is a lower value , making it easier to accelerate the flywheel basically.

a 12lb vs 8lb flywheel

moment of inertia = Mr^2/4
assuming they are a 24" diameter (I have no idea what they really are)

12lb, I=(12*(24^2))/4 = 1728 lb-in^2
8lb, I=(8*(24^2))/4= 1152 lb-in^2

the 8lb flywheel is 1.5x easier to spin. so it take less power to spin it, and it'll accelerate faster, the only problem I see with this is getting used to shifting, catching first gear is gonna be a bit more difficult, and you'll probably want a betterthan stock clutch disc. you'll most likely burn up a clutch disc or two getting used to the way the drivetrain reacts with a lightened flywheel. a small tap of the gas is going to rev the engine up faster now which is good and bad.

so you really don't gain any power by using a lightened flywheel , it just takes less power to spin the flywheel.

3. ### asmallsolSuper Moderator

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I for a disc rotating on the axis perpendicular to its center of mass is I=(1/2)mr^2 (what a flywheel does)

your equation is for the rotational inertia through a diameter, which would be like spining a coin on a table.

I Have driven 2 cars with very light flywheels, one being the Toda flywheel (is like 8 something) and the ACT prolite which is 8.8.

Search for a post by me about the reasons I did not go with the Kautie Kumearlkadslr;kjl;kasjd;ljasdf flywheel (In the search, i spelled it right)

4. ### CRX-YEMSuper ModeratorModeratorVIP

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yup my mistake about the equations for I,
but it still makes the point.

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I've had a Clutchmasters flywheel (7.5lb) on my Civic's engine for a good 25k+ miles, and it's very easy for me to drive. Clutchmasters makes good stuff. Don't believe everything you read. By the way, Fidanza makes Clutchmasters' flywheels anyway- CM just puts their name on it.

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