TIP Engineering Forum Index TIP Engineering
Theory In Practice
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

LSD and effects

 
Post new topic   Reply to topic    TIP Engineering Forum Index -> Good Vibrations
View previous topic :: View next topic  
Author Message
schrist



Joined: 07 Apr 2007
Posts: 3

PostPosted: Sat Apr 07, 2007 1:52 am    Post subject: LSD and effects Reply with quote

Wiisass, I was wondering if you could give a comparison on LSD's (ie clutch vs gear) and how they effect the handling characteristics of a vehicle designed around autocrossing. A lot of people write a lot of things, and they usually don't know anything. Half of the people who describe the torsen don't even know how it works and how it biases torque. I want your opinion, if you have one, on the matter. Also, let me know how its going up there... so far away from blacksburg.
Back to top
View user's profile Send private message
Scooter



Joined: 12 Nov 2006
Posts: 18
Location: San Diego/Santa Cruz

PostPosted: Sat Apr 07, 2007 4:06 pm    Post subject: Reply with quote

Well one thing to keep in mind with torsen diffs is that they act like an open diff once a wheel is lifted. And if I'm not mistaken people lift tires pretty frequently at autox's. Just something to toss around.
_________________
Panda Drift!
Back to top
View user's profile Send private message
schrist



Joined: 07 Apr 2007
Posts: 3

PostPosted: Sat Apr 07, 2007 5:20 pm    Post subject: Reply with quote

well, I'm more concerned with the fact that a clutch type seems to bias torque based on the difference between input and net output torque and gear types bias torque based on torque difference between output shafts. In other words a clutch type will always lock up when there is a load applied (and resisted by the wheel/ground interaction) to it but a gear type will lock up more when there is a torque difference across it. So in effect a clutch type will try to lock both wheels together in acceleration and braking (or one or the other, depending on the ramps) and the torsen will only lock when there is a speed/torque difference between the two drive wheels. If you apply this to entrance/exit corners, straight line acceleration, etc, it will have significant effects on the handling and stability of the vehicle. I was wondering what Wiisass's take on this was.
Back to top
View user's profile Send private message
AceInHole



Joined: 28 Mar 2007
Posts: 12

PostPosted: Mon Apr 09, 2007 6:54 am    Post subject: Reply with quote

Scooter wrote:
Well one thing to keep in mind with torsen diffs is that they act like an open diff once a wheel is lifted. And if I'm not mistaken people lift tires pretty frequently at autox's. Just something to toss around.


It's true that tire lift is a common occurence in autocross. You just have to make sure you're lifting the right (i.e. non-driveline) tire. It's easily overcome by changing your droop travel and roll centers.
Back to top
View user's profile Send private message
Wiisass
Head suspension nerd


Joined: 09 Nov 2005
Posts: 131
Location: Philly

PostPosted: Thu Apr 12, 2007 6:01 pm    Post subject: Reply with quote

Steve, I've been thinking about this a little for the past couple days, but haven't really come up with anything worth writing. So short answer is it's out of my scope of expertise.

So I'll try and look at this a little more and see if I can come up with any good reasons for running one or the other for an autocross car.

Is this for the Mustang or the Formula car or just a general question?
_________________
TIP Engineering
Just put the TIP in.
R&D, damper development and fabrication.

jrud@tipengr.com
Back to top
View user's profile Send private message Visit poster's website AIM Address
schrist



Joined: 07 Apr 2007
Posts: 3

PostPosted: Wed Apr 25, 2007 2:50 pm    Post subject: Reply with quote

This is for the formula car, Temple and I are the two drivetrain presenters so I was trying to sort through the reasoning as best I can. I think i have a pretty decent grasp on it... but as usual my understanding can be greatly bolstered by a genius of your caliber.

-Steve
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    TIP Engineering Forum Index -> Good Vibrations All times are GMT - 5 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group