Moment of Inertia
Moment of Inertia I'd like some opinions on lightened flywheels. A few weeks ago I read a Hot Rod rag that made light flywheels sound like a good thing if you launch at a higher RPM. As I looked around I found some comments such as this on the Thunder Racing web site as part of the description of it's Fidanza flywheel.
"(Because lightened flywheels do not store as much inertia, they are not particularly suited to hard launching, such as what is required when drag racing. For this reason, Thunder Racing does not recommend them for serious drag racing applications.)"
Anyone have any practical experience moving from the stock "heavy" flywheel to a lighter one? Did it help or hinder your time at the track?
"(Because lightened flywheels do not store as much inertia, they are not particularly suited to hard launching, such as what is required when drag racing. For this reason, Thunder Racing does not recommend them for serious drag racing applications.)"
Anyone have any practical experience moving from the stock "heavy" flywheel to a lighter one? Did it help or hinder your time at the track?
Import guys swear by light weight clutch components. Even heavy, high HP Supras run very light flywheel/clutch assemblies. Personally I think that is the way to go. When I install my Liberty face plate T56 I will also install a light weight clutch and fluwheel.
Andrew
Andrew
from a physics standpoint a heavier flywheel stores and unloads more energy during the launch
the only experience i have is i built up a friends car very similar to mine. his has about 440 rwhp and a lightweight fidanze and i have about 410 rwhp and a stock flywheel and my car hits harder off the line then his does, but his spins up noticably faster
the only experience i have is i built up a friends car very similar to mine. his has about 440 rwhp and a lightweight fidanze and i have about 410 rwhp and a stock flywheel and my car hits harder off the line then his does, but his spins up noticably faster
TECH Regular
Joined: Feb 2003
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From: Spring Hill, TN
The heavier flywheel will result in better launches when you are doing high RPM clutch dumps on slicks. Without that level of traction, the flywheel can't make that much difference.
Lighter ones will enable quicker acceleration after launch. Whether one will result in a faster 1/4 mile is unknown because in some cases it might be sacrificing the launch.
When the car does road racing, then it gets the advantage of acceleration out of each turn without the penalty of a slower launch.
Lighter ones will enable quicker acceleration after launch. Whether one will result in a faster 1/4 mile is unknown because in some cases it might be sacrificing the launch.
When the car does road racing, then it gets the advantage of acceleration out of each turn without the penalty of a slower launch.
TECH Addict
Joined: Nov 2005
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as far as physics goes, a lightweight flywheel will reduce rotating mass and thus allow more power to be transmitted to the wheels while adding increased acceleration.
From a 1/4 mile standpoint, I could speculate, but the truth is there's a hell of a lot more impactful variables that can mess with times than a few lbs off rotating mass.
In theory, less rotating mass = less energy stored = higher rpm clutch dump necessary for equivalent launches.
While rolling, less rotating mass = quicker acceleration
Quicker acceleration and more power transferred to wheels = higher chance of tire spin
From a 1/4 mile standpoint, I could speculate, but the truth is there's a hell of a lot more impactful variables that can mess with times than a few lbs off rotating mass.
In theory, less rotating mass = less energy stored = higher rpm clutch dump necessary for equivalent launches.
While rolling, less rotating mass = quicker acceleration
Quicker acceleration and more power transferred to wheels = higher chance of tire spin
For dig drag racing stick with your stock one. Or get a billet spec... Think about what happens when you release your clutch. Your flywheel is spinning at engine speed, your clutch grabs the flywheel. This is when inertia comes into play. The more rotating force there is at that time in the flywheel the more load it's going to carry down the line in the drivetrain. The exact opposite is true while already rolling. When tremendous amounts of inertia isn't needed to move a drivetrain you've got less rotating mass, which is less work your motor has to do. It's all application related in my opinion. Roadracing = Lightweight Dragracing = Full Steel
