...

Go Back   Lateral-g Forums > Technical Discussions > Chassis and Suspension
User Name
Password



Reply
 
Thread Tools Display Modes
  #1  
Old 05-30-2006, 11:31 AM
whitess whitess is offline
Member
 
Join Date: Jul 2005
Location: Colorado
Posts: 40
Thanks: 0
Thanked 0 Times in 0 Posts
Default Snap oversteer/understeer

I've heard these terms mentioned a lot, but I don't know what they are and what causes them. Any help would be appreciated.
Thanks,
Larry.
Reply With Quote
  #2  
Old 05-30-2006, 02:13 PM
XcYZ's Avatar
XcYZ XcYZ is offline
Administrator
 
Join Date: Jun 2004
Location: Rochester, Minnesota
Posts: 8,998
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Usually they are implying that the car goes instantly loose or tight with little or no warning. Some of the things that could cause that are a cut tire, suspension bottoming out, or the chassis bottoming out on the ground.
__________________
Scott

My LS7 69 Camaro
Reply With Quote
  #3  
Old 05-30-2006, 05:09 PM
Mean 69 Mean 69 is offline
Senior Member
 
Join Date: Jul 2005
Location: Carlsbad, CA
Posts: 375
Thanks: 0
Thanked 0 Times in 0 Posts
Default

The late model Mustang guys use this phrase a lot. If you are familiar with the rear suspension design, you'll note that it is a triangulated four link setup, not unlike that used on the earlier A bodies and some other cars/kits. In this example, they are describing what happens when the system "uses up" the available compliance of the suspension bushings, and the result is a virtual metal to metal bind. When this happens, the car looses rear grip due to the immediate change in suspension bind, and the rear of the car comes around, right now. Having had a couple of these cars, it is a very real condition, not terribly friendly, pretty much impossible to recover from.

I have never heard of snap understeer, though I am guessing that it too could/does exist, I think the most likely scenario would be when something on the front binds up hard, and causes the front end to abruptly wash out.

Mark
Reply With Quote
  #4  
Old 05-31-2006, 09:25 AM
whitess whitess is offline
Member
 
Join Date: Jul 2005
Location: Colorado
Posts: 40
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Thanks all, that helps a lot.
Larry.
Reply With Quote
  #5  
Old 05-31-2006, 12:41 PM
Marcus SC&C's Avatar
Marcus SC&C Marcus SC&C is offline
Senior Member
 
Join Date: Apr 2005
Location: S.E. PA.
Posts: 169
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Hey Larry! On your SS the main problem is the convergence angles of the upper arms in the rear. With stock Squish-O-Matic bushings and the U channel arms it`s not too pronounced because the front end will push bigtime before the rear ever gets ugly. Although it WILL bite you if you`ve got serious horsepower and get it sideways! I good friend put his big block `87 Cutlass into a bridge abutment like that. It`s aggrivated by low compliance bushings and box section arms with little or no torsional flex. We`ve had good luck with Currie Currectrac arms with their Johnny joints. It`s not the ultimate solution but they work very well within the constraints of the original suspension. As you know (and I know Mark will agree with me here!) a better solution is a 3 link like the one we`ve been testing and running in our G-5 car for 3 years or so now. Of course that kind of thing is a lot more pricey... Mark SC&C

Last edited by Marcus SC&C; 05-31-2006 at 12:56 PM.
Reply With Quote
  #6  
Old 05-31-2006, 01:12 PM
McssGmachine's Avatar
McssGmachine McssGmachine is offline
Senior Member
 
Join Date: Nov 2005
Location: Arlington ,TX
Posts: 214
Thanks: 0
Thanked 0 Times in 0 Posts
Default

I hate to jack this thread, but do you have any updates on the 3-link Marcus?

Thanks
__________________
BRIAN WEST
Reply With Quote
  #7  
Old 05-31-2006, 03:27 PM
whitess whitess is offline
Member
 
Join Date: Jul 2005
Location: Colorado
Posts: 40
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Howdy to you too Mark!
Groovy, I learn sumpin' new all the time.
I thought that might be what I was experiencing from the front end of mine, but I guess not. Win a few, lose a few, eh?
What I get happens when I'm driving on the interstate and go into a curve. It doesn't like to turn and wants to keep going straight, much worse to the left than to the right. I also get some of this same turning problem around town, turning from one street to another and on curves, there it's almost like there's less pump pressure on the left as the right. If I let up on the wheel it tries to go back straight, in town and highway, would part of this be the dreaded "understeer"? Or maybe sumpin' in the alignment settings? If it's confusing let me know and I'll run it by the shop.
Larry.
From Colorful Colorado

Last edited by whitess; 05-31-2006 at 03:39 PM.
Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:42 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.
Copyright Lateral-g.net