Quote:
Originally Posted by stugray
Good link!
Here are a few quotes (anything sound familiar?):
"I am thoroughly happy there is another math man on here.
I do appreciate the effort. However as you know cars are a system of systems. Overall the mmi of the driveshaft is very small when compared with the rest of the drive train. Consider a 40lb crank with weights out at the ends. A 20-30lb flywheel/ torque converter with a huge radius. 30lbs of small radius components in the trans. A big heavy ring gear. Big heavy brake rotors and very big heavy wheels and tires. That is a lot of rotating weight. IMO the effect of the driveshaftis negligible. Both designs, steel and aluminum, are quite efficient compared to the rest of the system.
IMO the biggest advantage of the aluminum shaft is its corrosion resistance. "
AND
"Rotational energy = 1/2 m*rs^2*w^2
Translational energy = 1/2 m*v^2
m=mass; w=angular velocity; v=velocity of car; rs = radius of driveshaft ;
Let's say that the rear diff is 3.73 then the angular velocity of the ds is w=3.73*v/(8.67*rs)
The 8.67 is the ratio of the wheel radius over the driveshaft radius.
It turns out that the overall energy needed to rotate a driveshaft is about 1/10th that needed to move it forward. Then compare it with a 3000 lb car and it's a tiny fraction of the energy."
AMEN!
Look, I launch BIG rockets for a living. Does Physics say that IF I replace the 50 Steel bolts on the 1st stage adapter ring with titanium (for a difference of 1 pound), that physics says there will be a difference in the acceleration when the rocket leaves the pad? - YES!.
But HOW much difference when talking about a launch vehicle that weighs 1.1 MILLION pounds at liftoff? IN THE NOISE
|
Stu, you need to chill.
You've already said that you acknowledge there is a small benefit of reducing drive shaft mass.
What you're doing now is coming off as a total fucking tool with your smarter than us attitude. With the only purpose of supporting your personal OPINION that it's not a terribly efficient mod from dollars to results. You don't get to make that decision for others.
Basically, you're a d!ck.