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My tuner told me he had to turn my flywheel 3 times to smooth it out for my King Cobra Clutch install. I guess the flywheel was kinda warped. I have a couple of other things I want to do to the car (24 injectors, 1.7 rockers and performance springs) now. I was wondering if my flywheel is still slightly warped, can it hurt my new clutch and should I go ahead and purchase the aluminum flywheel and wait on my other stuff.
 

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I installed a SPEC aluminum flywheel at the same time I put in a SPEC stage 2 clutch. Honestly, I didn't notice a huge difference in drivability or performance. MM&FF wrote an article on aluminum vs. steel flywheels and aluminum was the clear choice for road racers/track cars. Aluminum also came out slightly ahead in the 1/4 mile drag comparison (though they kind of fudged the numbers because they launched the car with the aluminum flywheel at a higher RPM).
 

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In all honesty I don't see the benefit of an aluminum flywheel.

I remember guys running aluminum flywheels on their late 60 Chevelles when I was in HS in the late 70's (yes I should change my name from GTDan to Dyno(saur)Dan). They claimed that they were running lighter marine flywheels, had less mass weight and that their motors would rev faster. But, if they did not have their motors balanced properly with a lighter HB on the front, then the balance on their motor was all messed up. Running a lighter flywheel on a boat was much different from a car because in those applications a load was placed on the crank from the jet drive unit or the water pressure on a propellor all the way through to the crank.

On our cars we normally have to have the weight on the harmonic balancer matched up with the flywheel's weight. The only difference (none with the weight since its needed to be balanced) is the cooling characteristics of aluminum and its ability to displace heat faster.

I think the differences are minimal for part street/part track cars. For full track cars then every extra advantage counts.
 

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bluestreak said:
I installed a SPEC aluminum flywheel at the same time I put in a SPEC stage 2 clutch. Honestly, I didn't notice a huge difference in drivability or performance. MM&FF wrote an article on aluminum vs. steel flywheels and aluminum was the clear choice for road racers/track cars. Aluminum also came out slightly ahead in the 1/4 mile drag comparison (though they kind of fudged the numbers because they launched the car with the aluminum flywheel at a higher RPM).
They launch it higher because they Al flywheel is lighter, it has less rotating mass which is why it revs faster. That's also the reason when you drop the clutch from a stop the rpms come down further.
 

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Guarddog II said:
If its not balanced you need to replace it because it will damage your internals.

However, I'm not sure what the hell your mechanic was saying when he said he had to turn the flywheel. I've never heard of anyone machine balancing one of those things, you just replace it.

If he meant he had to change the positioning--don't think so, it only goes on one way.

Regardless if you don't have many mods, you can replace it with a stock one for around $100.

Otherwise, your money is better spent on other things like those rockers, cam, and other go fast goodies...
Turning the flywheel means putting it on a lathe and machining off a few thous to make it uniform, take off the high spots. I've heard of it plenty, but never had good results with it. It's better to just buy a new one...
 

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Turning a flywheel doesn't have anything to do with circumference (unless you picked the wrong word)

You usually get a flywheel milled/shaved to make the surface for the clutch to seat on flat. It's exactly the same idea as turning rotors or getting the bottom of your heads milled.
 

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Man, that was a major error on my part.

I was thinking of wrong part for some reason.

Back on topic, no I wouldn't get an aluminum flywheel. They are expensive and you wont' really see the gains as other mods for the bucks.

I would however get a new flywheel, especially if you feel vibration. You should be able to get a new one for fairly cheap.
 

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94cobra2615 said:
Turning a flywheel doesn't have anything to do with circumference (unless you picked the wrong word)

You usually get a flywheel milled/shaved to make the surface for the clutch to seat on flat. It's exactly the same idea as turning rotors or getting the bottom of your heads milled.
Yeah, I guess you could do them on a surface grinder. We always did rotors on a lathe with a brake rotor chuck coming at it from the pad surfaces... I guessed flywheels would be done the same way...
 

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A theory of mine which probably isn't correct is a steel flywheel would be better for durability as less rotating mass equals less momentum which means more strain on the motor for drag slick launches.
 

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You'll loose launching momentum, but in theory your motor will rev up faster. Its kind of like the aluminum driveshaft, its there but in theory you won't feel it. Its just saving weight and less rotating mass.

However, people get aluminum driveshafts because their stock driveshaft is screwed up AND they're not too expensive. If you get a deal on an aluminum, than its up for debate, but if we're talking hundreds of dollars more than a stock one than there is no comparison.
 

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94greenvert said:
I can get an OEM piece for $129 and the cheapest I've found for an aluminum one with around $300
Is that for a driveshaft or flywheel? WOW that's expensive.

FMS Driveshafts can be found online for $139 from Diversified.
Cast-iron flywheel for $90 from GEFracing.com
Billet flywheel for $220 <---ouch
 

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When I used to race r/c cars, flywheels came into part too. We had lightweight aluminum ones along with bigger solid aluminum ones. You could really tell a difference between the two when you switched them in and out. The lightened aluminum ones would allow the engine to rev faster and provided quicker acceleration. But the heavier and bigger aluminum ones would allow for a more steady idle due to the rotating mass and help out down low. Not sure if this would apply to real cars though. I would imagine with an extreme cam, you'd get better idle characteristics with more rotating mass.
 
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