What are the advantage and disadvantage of a light weight flywheel
#2
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I heard that the very light weight flywheels tend to be less friendly when getting the car going from a stop. The car may stutter a bit or feel a bit shaky when getting going. Also, I heard that when going full throttle, the rpm's not only get up faster, but also drop faster when changing gears. There's an advantage and a disadvantage in the lighter weight flywheel. I just went with the Streetlite flywheel opposed to getting the Prolite flywheel from ACT since it has a very good balance of both performance and street driving.
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In general, a lighter flywheel will mean that the car will rev more freely. Your engine will be more responsive and your acceleration will be increased, partially because you'll be able to shift faster.
The bad thing about lightened flywheels on turbo cars are that (supposedly) the weight of the flywheel helps the turbo spool up quickly. So if you go too light, your turbo won't spool as fast.
The bad thing about lightened flywheels on turbo cars are that (supposedly) the weight of the flywheel helps the turbo spool up quickly. So if you go too light, your turbo won't spool as fast.
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This is the same difference as trying to spool up the turbo in 1st gear vs. 5th gear. You can spool up to 20psi at very low rpms in 5th gear whereas it'll happen much later in 1st gear due to the engine being loaded up much more in 5th gear.
If you wanted your turbo to spool more quickly, you can stick a heavy *** flywheel in your car or put 500lbs of weight in the trunk. I can guanrantee you that your car will be slower though.
The one negative of a lighter flywheel is that it makes taking off from a stop more difficult as there's less inertia. Otherwise, nothing but benefits as it 'frees' up power by reducing inertia and weight, makes rev-matching/downshifting easier as the engine revs more freely, and I'd guess that it lessens the wear on the clutch and tranny on shifts due to less inertia. BUT, it probably increases clutch wear a bit when starting from a stop as you'll need to slip the clutch a bit more.
Last edited by spdracerut; Dec 29, 2008 at 12:43 AM.
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lol lol lol every day theres something new. That is very incorrect sir. Actually a lighter flywheel lets the engine rev quicker, so u actually get into the engines power band alot faster than with the heavier flywheel.
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Originally Posted by maperformance
With turbo cars you don't want to go too light because you need the extra load to help with quick spool.
Last edited by al3xx; Dec 29, 2008 at 08:02 AM.
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^^ You won't notice a HUGE difference because the stock flywheel is 13.9 lb and the ACT StreetLight is 13.1 lb. Obviously the weight could be distributed way differently such that the StreetLight has much less rotational inertia, but you'd have to have both side by side to see if that is the case. The Exedy flywheel that comes with the twin disc is 12 lb, so there's a bigger difference there.
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Go grab a physics book, a basic book on engines (well, maybe not too basic), and draw your own conclusions.
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^^ You won't notice a HUGE difference because the stock flywheel is 13.9 lb and the ACT StreetLight is 13.1 lb. Obviously the weight could be distributed way differently such that the StreetLight has much less rotational inertia, but you'd have to have both side by side to see if that is the case. The Exedy flywheel that comes with the twin disc is 12 lb, so there's a bigger difference there.
#14
I put in the lightest ACT flywheel (Pro Light - 11 or so lbs.) along with the ACT 6 puck sprung clutch. The weight difference is not much between stock and the ACT part as a previous poster said.
It feels great and the only issue I have driving on the street is how hard and fast the clutch grabs over the stock unit. If I had to break down why I have to tap the gas lightly before taking off i would say its 95% due to the ACT clutch grabbing harder and 5% due to the lighter flywheel.
Once you put a setup in like this you will notice a slight increase in how fast the motor revs but don't expect any amazing gains since there is no huge difference in weights. After putting about 300 miles on my clutch I have no issues (50% due to me learning how to drive with it and 50% due to it breaking in.) I would say if you are going to put a new clutch in, go ahead and put the lighter flywheel in too. I have no regrets from doing it and I was really worried before putting it in!
It feels great and the only issue I have driving on the street is how hard and fast the clutch grabs over the stock unit. If I had to break down why I have to tap the gas lightly before taking off i would say its 95% due to the ACT clutch grabbing harder and 5% due to the lighter flywheel.
Once you put a setup in like this you will notice a slight increase in how fast the motor revs but don't expect any amazing gains since there is no huge difference in weights. After putting about 300 miles on my clutch I have no issues (50% due to me learning how to drive with it and 50% due to it breaking in.) I would say if you are going to put a new clutch in, go ahead and put the lighter flywheel in too. I have no regrets from doing it and I was really worried before putting it in!
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Do you trust everything a shop tells you? If you listen to the old school domestic guys, they'll tell you that you need backpressure in the exhaust to make torque
Go grab a physics book, a basic book on engines (well, maybe not too basic), and draw your own conclusions.
Go grab a physics book, a basic book on engines (well, maybe not too basic), and draw your own conclusions.
Last edited by al3xx; Dec 29, 2008 at 08:29 PM.