Rotational Mass - All Stock vs. All Super-Light

[Guest Mike]

Theory flies out the window right along with time here in the real world, eh? Theory, theorems, formulas and mathematics are simply tools to give us a head start on our inevitable postulatory guessing games and ensuing trial-and-error experiments. For the lazy man like me this is a real PITA:? I look forward to growing a few brain cells via your future posts:wink:

[dimsum]

HAHA, in theory...

Moment = Force x Distance

thats the basic equation and easiest to solve. (trust me I took Statics twice)

But in Dynamics we have done some simple automotive applications, but nothing too in depth. But I do know that the radius of things do affect rotational velocity and moments and forces needed to move them after overcoming friction.... so all these tie into play.

 

This is an interesting thread, so I thought I would add my two cents.

 

As people have said before, the equation to calculate torque is:

distance * force

which nets you a unit of ft-lbs. If you are rotating something around a centerline, the amount of torque you need to move it is dependent on how heavy the item is and how far away it is from the centerline.

 

Bringing this back to the discussion of flywheels, weight removed from the outside (closer to the outer edge where the teeth are) of the flywheel will make a bigger difference from weight removed from the center of the flywheel. Based on the equation, the distance from the center of the flywheel to the location of the mass affects the torque required for rotation.

 

This same concept can be applied to the drive shaft. However, I think rotational speed also comes into play with the drive shaft, although I'm not sure how it fits into the equation. Time to do more research.

[dimsum]

Is it fair to assume that the consensus regarding which components have the most effect on power/torque (in order of diminishing effect) is as follows?

 

1. Flywheel

2. Torque converter "or" clutch assembly

3. Wheels/tires

4. Pistons

5. Crank shaft (mostly counter weights)

6. Rods

7. Drive shaft

8. Half shafts

 

With respect to numbers 4, 5, and 6:

 

I think lighted pistons, crankshaft, and rods will be more beneficial in increasing engine RPM. The lighter these components are, the faster your engine can spin (higher redline).

 

In my view, the benefits from lightening your engine internals differs from the benefits of lightening your flywheel and wheel/tires. But, I guess it all comes down to making your Z faster.

[Guest Mike]

That's what it's all about... FASTER Z's!! It makes sense that reducing weight wherever one can is good but reducing weight on rotating and reciprocating masses is even more important. I'm sure this is very academic to those more experienced individuals but, to a noob like me, it's a great thing to learn.

 

Lightweight engine internals: I know this allows for higher RPM's before it flies apart but the engine spins up more rapidly too, doesn't it?