mad-butcher
|
| posted on 25/4/09 at 06:42 PM |
|
|
Caster question. answers in simple form
Hi Guys
As above, I've built several m/cycle racing outfits in the seventies so have a rough idea of lead and trail, Struggling to get my head round
caster angle on a car (MK) sierra upright
1) how do you measure it
2) is it a line drawn through the top ball joint, stub axle and bottom ball joint taken to the floor. then that would be the caster angle.
3) If 2 is correct how is the caster angle affected by using offset mushroom adjusters, because by having the mushroom fully forward ( to increase
caster) you are now unable to draw a straight line through the top ball joint, stub axle and bottom ball joint,
simple answers please I'm a wagon driver not an engineer
tony
|
|
|
|
|
blakep82
|
| posted on 25/4/09 at 06:44 PM |
|
|
its the line between the top and bottom ball joint, NOT the upright.
the angle's then measured against vertical
so those mushroom thingys don't affect the castor angle. which thinking about it now, makes me not sure what the point of them is
[Edited on 25/4/09 by blakep82]
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
|
|
|
mad-butcher
|
| posted on 25/4/09 at 06:47 PM |
|
|
your cars starting to look good
tony
|
|
|
mr henderson
|
| posted on 25/4/09 at 06:50 PM |
|
|
quote:
Originally posted by blakep82
its the line between the top and bottom ball joint, NOT the upright.
Indeed
|
|
|
blakep82
|
| posted on 25/4/09 at 06:50 PM |
|
|
thanks tony  its slowly coming together lol very slowly. been out painting my mates bonnet today, might drag myself back out there today to do some
of my own car!
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
|
|
|
blakep82
|
| posted on 25/4/09 at 06:56 PM |
|
|
quote:
Originally posted by Paul TigerB6
As above - its just measured through the centre of the ball joints top and bottom so to increase castor you want to get the top balljoint further back
if thats what the mushrooms let you do
but thats the thing, the mushrooms don't let the ball joints move back the ball joint is fixed by the wish bones. only moving the top wishbone
back (or the bottom one forward) will increase castor
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
|
|
|
mark chandler
|
| posted on 25/4/09 at 07:02 PM |
|
|
Look at a motorbikes forks from the side, the amount if lean back from bottom to top is caster
|
|
|
Hellfire
|
| posted on 25/4/09 at 07:06 PM |
|
|
The mushroom with the offset hole is there to provide mechanical trail which will aid self centreing.
As mentioned before, the only way to alter the castor is to move the top or bottom balljoints and the only way to do that is to move the wishbones to
which they're attached. This can be achieved by either modifying the top or bottom wishbone (or both) or by moving the brackets.
Phil
|
|
|
StevieB
|
| posted on 25/4/09 at 07:10 PM |
|
|
Does moving the centre of the stub axle behind the castor line (top and bottom ball joint) achieve the same result as dialing in more castor? I think
it does.
|
|
|
Hellfire
|
| posted on 25/4/09 at 07:16 PM |
|
|
The offset hole in the mushroom is there to provide maximum mechanical trail on the Sierra upright. Although trail and castor are related, they are
not the same thing.
Phil
|
|
|
wozsher
|
| posted on 25/4/09 at 07:25 PM |
|
|
The Castor angle is a line between the top and bottom balljoints in relation to vertical. The offset mushroom inserts are used to allow for the anti
-dive that Ford built in to the geometry for the Mcpherson strut set up,
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
|
tomprescott
|
| posted on 25/4/09 at 07:27 PM |
|
|
Mushroom is there to let there ball joint sit where the macpherson strut would go, angled ones aid in self centering but thats not its primary
function!
|
|
|
wozsher
|
| posted on 25/4/09 at 07:39 PM |
|
|
Castor angle dosent just provide self centering its also an essential requirement for overall handling
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
|
