N197TR4@cs.com wrote:
> Peter just finished a TR4 in the spirit of the "Works" cars. It was a four
> year project. Please someone do the formality of the 'second' and Peter can
> do a short introduction of himself and the car as he desires.
>
> Mark Bradakis please add:
>
> Peter Vucinic <vucinic@b140.aone.net.au>
>
> Peter also asks about modifications necessary for adding negative camber to
> the TR4. I have shared our experience of sectioning the upper A arms and
> shortening to achieve about 1.75 degrees of camber. This might be a good time
> to review the different methods of adding camber. I know there are others
> seeking this information.
>
> Regards,
>
> Joe Alexander
I second the motion, being of kindred spirit, for I race a loose replica of the
factory team cars.
There are several ways to change the camber, inlcuding welding a Heim joint to
the upper A-arm to give a wide range of adjustment.
Many of us shorten the upper a-arm by cutting out a section of the innermost
straight section (near the pivot) and rewelding, and some of us (like me) then
weld a short piece of flat across the open section, to box it in.
The amount you must remove from the upper arm depends on how much you have
lowered the car (if any), since with this car's suspension geometry, the camber
changes if you lower the car by, for example, shortening the spring, removing
the
upper aluminum spacer, etc.
Therefore, you should measure the camber you now have (laden) and figure out how
many degrees you want to change from where the car is now. As a generality,
then,
every .100 inch that you remove changes the camber by 1/2 degree.
The method I used for calculating this is that a rough measurement from the
upper
to lower pivot on the spindle is 11". If the angle you desire is .5 degree, then
simple trig calculation says that the amount the top end must move for 1/2
degree
is about .100. Somebody correct me if I'm wrong -- and yeah, it won't be exactly
perfect, but then cutting the thing off with a hacksaw isn't the most precision
operation, either, so if anybody knows a better way, have at it.
When I did mine I thought it was important to keep the upper pivot bore
centerline absolutely perpendicular to the faces that bolt to the outer upper
ball joint to avoid premature bushing failure, so I made a simple jig out of a
big chunk of steel, a bar the size of the upper a-arm bore, and an old upper
ball
joint. Again, not perfect, but better than nothing.
Good luck!
--
TR6 -- 29 and still running
TR4 -- 39 and still racing
uncle jack -- yeeehaaa
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