joolsmi16
|
| posted on 24/6/07 at 06:54 PM |
|
|
steering arm angle
Hi all, having reposition my steering rack so that it now sits behind the centre line of the front wheels. My steering arms are now at a different
angle is this okay.
Thanks
 
Rescued attachment HPIM1443_Small.JPG
|
|
|
|
|
t.j.
|
| posted on 24/6/07 at 07:01 PM |
|
|
The Q is not where but how the steering-rack is placed.
It's important to know if you placed it at the right spot.
You don't want any bump-steer.
So 3D-drawing is the best.
If not try to make a picture in front of the car so we can judge.
Why did you replace the steering-rack?
Mine is in front, no bump-steer. steeringarms almost parrallel to the bottom. In fact a few mm lower.
Grtz
Please feel free to correct my bad English, i'm still learning. Your Dutch is awfull! :-)
|
|
|
joolsmi16
|
| posted on 24/6/07 at 07:09 PM |
|
|
steering arms
I reposition the rack to reduce bump steer to have the rack pivoting at the same angles as the wishbones.
Having read a little more about ackermans the angle steering arms are the norm just surprised at the amount of angle.
Quote "The steering arms are angled inwards to create a means for the wheel angles to change at a different rate. This is the basis of the
Ackerman Steering Principle and creates this unequal angular movement of the wheels".
|
|
|
mark chandler
|
| posted on 24/6/07 at 07:10 PM |
|
|
You have increased your ackerman angle by doing this, ie the turn in rate on the left wheel is different from the right.
From you picture it looks like the rack is very low, if you draw a virtual line between the pivot points on the suspension backets when the wheels are
straight ahead the the ball joint in the rack should be in the same plane.
The acid test is to centre the steering, then from full droop to fully compressed the front wheels should stay pointing straight ahead, if not you are
suffering from bump steer which is not good.
You may want to lift the rack to achieve this holy grail, I took 4" out of my rack to get this right.
Bob C's picture kind of shows this, although its from the back not front.
You really need to spend a lot of time getting this right or it will handle badly.
Regards Marklinky thing
[Edited on 24/6/07 by mark chandler]
|
|
|
joolsmi16
|
| posted on 24/6/07 at 07:48 PM |
|
|
steering arm
not sure on the height of the rack but I positioned it so the steering arms arch identically to the bottom wishbone, and the steering arm pivot point
are in line to that of the pivot points of the wishbones.
|
|
|
MikeRJ
|
| posted on 25/6/07 at 06:30 PM |
|
|
quote:
Originally posted by joolsmi16
Having read a little more about ackermans the angle steering arms are the norm just surprised at the amount of angle.
Quote "The steering arms are angled inwards to create a means for the wheel angles to change at a different rate. This is the basis of the
Ackerman Steering Principle and creates this unequal angular movement of the wheels".
You are confusing the steering arms with the track rods. The steering arms are the bits on the upright that the track rod end bolts to. They are
either bolted on or cast as part of the upright. The parts you are showing in your picture are the track rods.
The relative angles of both will affect ackerman, but normaly the ackerman will be introduced by the steering arms and the track rods will be more or
less straight comming out of the rack looking from above.
You might find your setup gives excessive ackerman angles, but how this will affect handling I couldn't say.
|
|
|
