Sounds right.
The only place I'd disagree is creating adjustable camber. There's lots
of ways to do this, but most of them make camber gain worse than it
already is. Best way I've found is to move the inner pivot of the upper
arm inwards. You can do this in a stock-looking manner with a bit of
effort.
http://picasaweb.google.com/billbab/FrontSuspensionStuff These pictures
show my fairly funky suspension measurement tool--a laser level that
bounces off a flat mirror stuck to the front disk. I bounce the laser
onto a sheet of graph paper, (second picture) crank the suspension
through 1/2" increments and mark the dot. The result is camber gain
shown as vertical position and bump steer as horizontal. The fourth
picture shows the original wild bump steer. The tight "J" on the left is
what I wound up with. Under normal conditions I never reach the area at
the bottom where it loops into a J. the third picture is the suspension
on the Cheater TR3. Worked mighty good. I ran about one degree of caster
without binding using a stock lower trunnion that was probably worn. The
inner pivot point is moved inwards about 1 1/2 inches and the arms are
generally set to be slightly _longer_ than stock.
> -----Original Message-----
> From: owner-fot@autox.team.net
> [mailto:owner-fot@autox.team.net] On Behalf Of Larry Young
> Sent: Saturday, September 30, 2006 2:01 PM
> To: Susan and Jack
> Cc: fot@autox.team.net
> Subject: Re: [FOT] TR3A/TR6 front suspension interchange - Help needed
>
> You're making this harder than it needs to be. The upper A
> arms changed early during TR4 production and remained the
> same through TR6 production. Changing the A arms gives you 3
> degrees of caster rather than 0 degrees. To make the
> conversion you change the A arms, the upper ball joint, and
> the trunion, that's it. This will not change the camber. If
> you want to change from the stock +2 degrees of camber you'll
> have to do other modifications. If you lower the car 1 1/2
> inches the camber will change to about +1.6 degrees, which is
> not enough. If you want to get -1.5 degrees you need to move
> the upper ball joint inward about 1/2 inch. The neatest way
> to do this is to redrill the holes in the ends of the A arm.
> However, since the inner hole will now be off the flat
> portion, you can add a small piece of pipe to fill the space
> between the A arm and the ball joint surface. These
> modification do not give you adjustable camber. If you want
> adjustable camber like in the TR6, I believe you would have
> to do some major modifications to frame members. This has
> been done, but most TR3/4 racers don't do this.
>
> You do not need to change the caliper mounting plate to
> change the suspension geometry. The caliper plate changed
> when the calipers were changed from the early clam shell type
> calipers to the later TR4-6 calipers.
>
> Larry Young
>
>
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