assimetric rear axle

[Pedrot16]

I there

We are planing using a non-centered differencial, so right and left rear sub-axles lenghts are different.
my question is: using a torsen or a quaife therés any problem in acceleration or braking due to different shaft´s inercia?

thanks

sorry about my english..

[Pedrot16]

I there

We are planing using a non-centered differencial, so right and left rear sub-axles lenghts are different.
my question is: using a torsen or a quaife therés any problem in acceleration or braking due to different shaft´s inercia?

thanks

sorry about my english..

[SNasello]

If you make them both with the same size tube and same wall thickness then one will be stronger then the other and one will deflect more than the other. Look up how to calculate the stress and deflection on a shaft in torsion in one of your statics textbooks. You can design them so that they will have close to the same deflection and stress.

[JR]

I have wondered about this explanation. I mean, steel is stiff, how much can the angular twist differ from the short to the long tube... tiny fractions of a degree? This doesn't seem like it would effect driving.

[jeff-NIUMS]

I believe this (http://fsae.com/eve/forums/a/tpc/f/125607348/m/26910051431/p/1) is the topic you are looking for. Make sure to read through it all, as there is some good (and bad) information in there.

[Conor]

We are running a non centered diff this year and went through the calculations on the two different axle lengths. We used a program called Race Data Power to compare two axles of different lengths but same thickness and found that they actually differed by several degrees. It will be noticable...

[js10coastr]

I'm going to start coining the phrase

"If all else fails... do the calcs."

[Biggy72]

the calcs are pretty easy to do by hand as long as you can assume a torque.

theta=TL/JG

theta is the angle of twist, T is the torque, L is the length of the section of tube, J is the polar moment of inertia, and G is the shear modulus of elasticity.

J=pi/2*(ro^4-ri^4)

ro is the outside radius, ri is the inside radius of the tube.

[Pedrot16]

yes, thanks, but i´m talking about diferent inercias. i know that with a normal differential when using shafts with diferent inercias the car slips to a side, my question is if with a torsen or a quaife that happens too.

[D J Yates]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Pedrot16:
with a normal differential when using shafts with diferent inercias the car slips to a side </div></BLOCKQUOTE>

Can't say i've ever noticed that.

Remember that you're not only accelerating the drive shafts, but also the whole hub, wheel and drive shaft assembly. The inertia of the wheel is so many times larger that i doubt you'd be able to measure any difference in wheel acceleration even if you were driving the driving the wheels with the car jacked up in the air. Furthermore, since you're not just accelerating the wheels but the whole vehicle, the effect of difference in drive shaft inertia becomes even more insignificant.

[KU_Racing]

I think he meant to say different moments of inertia. If you use two shafts of the same material with different M/I's, you will notice a big difference as one shaft deflects more than the other in torsion.

[drivetrainUW-Platt]

To answer your question:
No http://fsae.com/groupee_common/emoticons/icon_razz.gif