At 12:10 PM 5/26/04 -0400, Don Vierling wrote:
>Now I'm intrigued also. Does anyone know what kind of angle change
>results from using the negative camber wishbone arm sets sold by Moss
>and/or Victoria British? I've perused the two catalogs, but there's no
>indication of what you end up with.
Not right offhand. This is a number that should be published in the
catalogs, but isn't.
As a sort of rule of thumb (and reasonable guess), the most commonly
mentioned number is 1 degree negative camber for competition work. Very
serious contenders may determine for themself if they want something
different, perhaps anything from 1/2 degree up to 1-1/2 degrees. If you
had ever seen a car with 2 degrees negative camber (maybe a dirt track
racer), you would think something was broken, and you definitely wouldn't
try to drive that car on the street.
>I need to install new lower A-arm bushings and I figured since I'm taking
>it all apart anyway, maybe I should just swap out the arms while I'm at it.
Change of a-arm length relative to camber change is the same as for the
previously mentioned shock shimming example. Change of A-arm length for
one degree camber:
sin(1) x 8.5" = 0.148"
You can have adjustable camber by using an ecentric pin in place of one of
the horizontal trunion bolts. This part would replace the original bolt
and the steel sleeve. The center of the adjustable pin would be the same
diameter as the OD of the original sleeve (.748" dia), and it would have a
male thread on both ends (1/2" fine thread) where it attaches to the A-arm
or shock arm. Slot one end (or both) to allow rotational adjustment with a
large screwdriver. If this part is made from 3/4" bar stock, the ecentric
offset can be up to 1/8", giving an adjustment range of up to +/-0.85
degrees of camber. This might be used in conjunction with 1 degree
negative camber A-arms to give adjustment range of 0.15 to 1.85 degrees
negative camber.
I do not know if anyone currently sells such a part for the MG, but any
racer type person considering inducing negative camber for serious
competition work should be interrested. I can't quite comprehend that
someone installing negetive camber A-arms might brashly assume that the
resulting camber angle might be the exact optimal angle for every
application. Maybe for a novice autocrosser looking for a little extra
edge, this first guess might be close enough, and they may have no
independent means to determine if any other angle might be better. If I
was competing in a class that allows camber change, I would bloody well be
interrested in determining the exact best angle and setting it accordingly.
$.02,
Barney Gaylord
1958 MGA with an attitude
http://MGAguru.com
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