I am looking to get a light weight flywheel for my N/A fc3s, and I was wondering if this would make a big difference in released hp from the reduction in rotating mass. I am looking to get the steel one, not the alminum one. I was alsohoping hat this would hlp cut some time off of my 1/4 mi. time too. Any input is appreciated. Thank you.

 

any reduction in drivetrain losses will help your quarter mile times. As far as it being a big difference... The car will feel more responsive to throttle input, and will accelerate slightly more quickly, but you're not got to cut a second off of your quarter mile with a flywheel. You will notice it, tho.

 

Oh yea, I know that it wont take off a second. But I am hoping that it will take off a tenth, or two.

 

10Lbs off the weight of the flywheel equates to approx. 200lbs taken out of the car, just to give you an idea.

 

I've driven several cars with light flywheels. The noticeable difference is in 1st and 2nd gears. The car will be much quicker in the lower gears. In third the difference isn't nearly as noticeable and by 4th and 5th there isn't much to be had. The downside, when specifically talking about 1/4 mile times, is that the light flywheel will be hardner to launch consistently and will require quite a bit more RPM if you're side stepping the clutch. Without really zinging the engine your 60', and as a result ET, may suffer. Light flywheels are more suited toward something like roadracing or autocross where there are no standing starts and the light effects are felt in both acceleration and braking.

 

If anything I bet you will lose time in 1/4 than if you ran the oem flywheel.In dragracing you want to keep the rpms high at all shift points,guess what happens with a light flywheel,very fast loss of rpms.

They are for road racing and not dragracing.Go catch a promod,or prostock team changing the tranny and motor out.The worst thing you can do if you want to dragrace is use a light flywheel.

 

Lighter rotational mass yeilds quicker acceleration, thus the noticeable SOYP differences in the lower gears. This is b/c the work required to accelerate any rotational mass goes up exponentially with RPMs. Drag racing, road racing, harness racing - doesn't matter what we do, we cannot escape the laws of physics.



What happens in drag racing is that a heavier flywheel will have more enertia (back to Physics 101) than a lighter flywheel. That stored energy is exerted during 'the launch'. This is why some people write off lightweight flywheels...it 'hurts their launch'. However, the initial start isn't everything. While you may have a better launch, given the same driving syle, w/a heavier flywheel - the engine still has to accelerate the flywheel, driveline, wheels, etc for the rest of the track. Spinning those requires work b/c they have mass - the lower the mass, the less work required to accelerate those. Still w/me?



Acceleration is everything, well for this discussion at least, and a lighter flywheel will yeild greater acceleration. Physics 101.



IMO, a light flywheel is a great modification. If you are worried about your launch and shifts - well, become a better driver. The car will feel quite different. Get some seat time and everything will come together.



-Carlo

 

Thanks Carlo. I appreciate you laying everything out for me like that. I just finished my second semester of Physics, and all the things you said were what I though too. I know that is thet way things are supposed to work, but I did not know if that was the way it helped out with the cars. But, if I can adjust to the flywheel, hopefully it will help out some. Thanks again.

 

general rule of thumb is if you launch and you have execissive tire spin ie it is easy to do a burn out. lighten the flywheel same if you come out of a corner and the engine has a significante problem raising RPM



If you dump the clutch and the engine bogs, you went to light with the flywheel and there is no stored enertia. or yet again you come out of the corner and the engine fails to build rpm.