Bump Steer / Rack and Pinion
Thread Starter
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
Bump Steer / Rack and Pinion
I am gathering parts and information in preparation to fab my own '92 Grand Am rack and Pinion conversion.
My question is about bump steer. My understanding is, you want the tie rods and the control arms so their arc of movement is together, right?
I have the stock gymkana suspension and 255/60R15 tires. It looks like the stock orientation of the tie rods is ideal (you would think it would be). So, can I just fab a bracket to go on the rack and pinion that would reach to the stock location of the tie rod ends, and just hook the stock tie rods to it without modifying them?
This is my steering I'm dealing with, so I need to get it perfect the first time. Thanks for any help.
God bless, Sensei
My question is about bump steer. My understanding is, you want the tie rods and the control arms so their arc of movement is together, right?
I have the stock gymkana suspension and 255/60R15 tires. It looks like the stock orientation of the tie rods is ideal (you would think it would be). So, can I just fab a bracket to go on the rack and pinion that would reach to the stock location of the tie rod ends, and just hook the stock tie rods to it without modifying them?
This is my steering I'm dealing with, so I need to get it perfect the first time. Thanks for any help.
God bless, Sensei
Last edited by a1sensei; Mar 12, 2009 at 02:14 PM.
Drifting
Joined: Jan 2006
Posts: 1,832
Likes: 38
From: Cedar,BC
That sounds like it will get you in the ball park of having the bump close to stock,which is not all that great if its like other GM front ends,especially if the ride height has been changed.Here's a bit of reading for you,it's meant for oval race cars but should give you a better understanding.
http://www.longacreracing.com/articles/art.asp?ARTID=13
http://www.woodwardsteering.com/inde...section-guide-
http://www.longacreracing.com/articles/art.asp?ARTID=13
http://www.woodwardsteering.com/inde...section-guide-
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Chris, Norval Willhelm came up with 17 5/8 for the proper tie rod lengths to minimise bump steer.....it was done some years after I did my install, and since I felt no problem....heck with it...but I have that note on the drawings I copied for you....
so that would be tie rod pivot center to same.... then to make the steel block a bit different than mine....still 1/2 inch thick where it mounts to the rack, but then you have to extend it up and at same height but out to the required location to catch his 17 5/8 length......mine are 19 & 21 like I said....so not perfect...
so that would be tie rod pivot center to same.... then to make the steel block a bit different than mine....still 1/2 inch thick where it mounts to the rack, but then you have to extend it up and at same height but out to the required location to catch his 17 5/8 length......mine are 19 & 21 like I said....so not perfect...
C6 the C5 of tomorrow
Joined: Nov 2000
Posts: 6,665
Likes: 2
From: Twin Cities Minnesota
It's a long and involved subject, do a search and you will be occupied for quite a while!
One thing to remember about bump steer is it is also called roll steer. This means that as you turn a corner and the car rolls, the front wheels may turn dur to the compression of the suspension. There are two way the wheels can turn, one way causes oversteer, the other causes understeer.
Common thought is you always want a little roll understeer as there are other factors that you don't have any controll over and going into oversteer is not a fun event. Understeer make the car more stable and easier to drive.
So this means you want a little toe OUT on suspension compression. How little?
Think of how much toe in you run, 1/16" 1/8" I feel that is a good roll steer number.
Lastly, look on my home page, click on my name over here <--- I talk about the R&P conversion some
One thing to remember about bump steer is it is also called roll steer. This means that as you turn a corner and the car rolls, the front wheels may turn dur to the compression of the suspension. There are two way the wheels can turn, one way causes oversteer, the other causes understeer.
Common thought is you always want a little roll understeer as there are other factors that you don't have any controll over and going into oversteer is not a fun event. Understeer make the car more stable and easier to drive.
So this means you want a little toe OUT on suspension compression. How little?
Think of how much toe in you run, 1/16" 1/8" I feel that is a good roll steer number.
Lastly, look on my home page, click on my name over here <--- I talk about the R&P conversion some
