Has anyone installed an Aluminum Flywheel for the street. Any pos and cons? Seems to me that would be a great HP(not much I know) and response upgrade. Thanks J.

 

need good clutch and low gears,,,and a engine that can REV.

 

They will give you great throttle response and are a bit forgiving as far as driveline shock goes . Forget about the HP ,,,,,,

Geo

 

I recently installed the lightweight nodular L-88 flywheel. Really have to feather the clutch on take offs now. I have the 3.09 ratio rear end right now. I'm guessing the situation will improve when I install the 3.55 gears.

 

I Have a 270hp, 4speed with 3.55 gears. So is it a worth while project, is it just faster off the line and easier on the engine?

 

i do not think an aluminum flywheel will be faster off the line...its more for like road racing and sprint type racing where sudden RPM drops are key.

 

It lowers your car's effective weight quite a bit in the lower gears, so it should be helpful in all situations as long as you can shift properly and can deal with the extra vibration.

 

I posted this same question in the Chevelle forum and got a lot of great responses from experienced guys...check it out.
http://www.chevelles.com/cgi-bin/for.../4/23586.html?

 

Pretty cool...

In the same line of thinking, I think this thread would also apply...
http://www.hotrodders.com/t46496.html

I'm just trying to find out where you can go to calculate on paper what the effect of this stuff is!

 

BillyShope nailed it in that thread. I've also stated the same thing in this forum a few times, but I'm too lazy to search for those threads.

What part are you having trouble calculating?

 

I'm having trouble with something called the polar moment of inertia. Its how you determine the difference of a "Weight" of a flywheel vs the location of the weight in the flywheel. I havent found an explanation that I can wrap my pea brain around...

Reason being that the weight farther away from the axis of rotation creates more centripetal force. (I'm not really sure that a fixed object is centrifigal or centripetal force that we're trying to see...) I just want to "know" what all the above means!

 

For the purposes of this sort of thing, the moment of inertia is calculated by summing up each piece of mass times the square of its distance from the axis of rotation. For a flywheel, you'd do this with an integral, although none of us knows how mass is distributed throughout it, so there's no point in me explaining that in much more detail.

The end result is the the moment of inertia will be less than the mass times the radius squared. This would be exactly true if all the mass in the flywheel were distributed at its edge, which of course isn't correct. If it were instead a uniformly dense disk, then its moment of inertia is half of the above value. A real flywheel would probably have a factor of 0.6-0.8 multiplying mR^2, although I'm just guessing.

Here's a numerical example: Say that your flywheel is 14" in diameter, and weighs 30 lbs (I think these are roughly the specs for the stock one). Its moment of inertia is then about 0.7*30*7^2=1000 lb-in^2.

Now say that you have an M20 transmission with 3.55 rear end and 26" tires. The gear ratios are 2.6, 1.9, 1.5, 1. In 1st gear, the flywheel adds an effective weight of 2.6^2*3.55^2*1000/13^2=500 lbs (!). The effective weights in the higher gears are much less, but still significant (270, 170, 70 lbs in 2nd, 3rd and 4th respectively).

Reducing the size and weight of your flywheel can have a major effect; especially with aggressive gearing.

 

Thanks gang, I believe I will stick with my steel. That link was very helpful and made me glad I still have my legs intacked.

 

Bottom line is: if you are road racing (or drag rascing and need quick RPM acceleracion(which means you are above your "needed" torque) then itis OK. For street use, you need the mass to store the torque for low RPM torque.

 

Best explanation I've seen yet! Thanks!