Differentials

[joevenzon]

I have implemented differentials in the refactor. I have a couple of questions.

One, I'm making provisions for proper modeling of AWD cars, with a limited slip epicyclic (torque-splitting) center diff that drives separate front and rear limited slip differentials. Is this the correct arrangement? Do real center diffs make use of slip limiting?

Two, I found that vamos models limited slip differentials as speed-sensitive limited slip instead of torque-sensitive limited slip. How does this affect handling, and is it worth also implementing a torque-sensitive type?

[zimluura]

here's where most of my mechanical knowledge comes from
torsen differential
http://auto.howstuffworks.com/differential6.htm

interesting blurb on the side about the hummer having 2 torsen diffs, and how to get one un-stuck.



i think for a tc6 you have 3 differentials
front = open
mid = viscous coupling
rear = torsen
i would think that not having at least the center differential be limited slip would make the awd a useless weight that you haul around. unless there's an electronic braking system at work.

and i always see front clips and long blocks as being sold "with awd transmission" so maybe that means the front differential is integrated into the transmission, or stuck to it.



it seems like each car could have things a little bit different. so the more optional differential types you feel like coding the better. if you can figure out a good way to provide for part-time 4x4 systems as well as awd that could be cool too.

[joevenzon]

Thanks for the input. The open and viscous coupling types are supported in the current refactor code. Viscous coupling is a type of speed-sensitive limited slip differential, and an open differential can be simulated by setting the anti-slip parameter to zero. I'll read up on the torsen and see if it's at all similar to an epicyclic diff with speed-sensitive anti-slip.

From some reading I did today, the Subaru Imprezza uses a viscous coupling center diff (50/50 torque distribution) and a viscous rear diff, so should be covered there.