Jack, one method you left out in your list below is heating and
bending the vertical links. This was apparently a solution used
years ago. My vertical links have been bent by the PO to create
1.5 degrees negative camber.
With that said, you already know I purchased a set of modified
upper a-arms from you and plan on replacing my vertical links with
ones that have not been bent and using your a-arms to create that
negative camber.
Your method seemed so much cleaner and safer to me!
Thanks
Brad
---------- Original Message ----------------------------------
From: "Jack W. Drews" <vinttr4@geneseo.net>
Reply-To: "Jack W. Drews" <vinttr4@geneseo.net>
Date: Tue, 10 Jul 2001 07:56:06 +0000
>Wes Dayton wrote:
>
>> Under our racing rules, we are allowed to run up to 2 degrees of
>> negative camber. After reading accounts from earlier FOT
questions, we
>> have unsucessfully attempted several mods (shortened upper
control arm,
>> etc) but have been less than impressed with our results. One
problem is
>> clearance of the ball-joint bolt/nut and the top of the spring
tower,
>> etc.
>>
>> Yesterday we were looking hard at a TR6 front suspension that
just
>> happened to be on the shelf. It would appear that we could use
the upper
>> arms, vertical link and trunnion etc. We'd need to modify the
TR3A lower
>> arm to accept the trunnion, but that looks to be pretty
>> straight-forward. It looks as though the 3A caliper plate would
still
>> bolt up, etc. This would also appear to end up with a stronger
overall
>> set-up.
>>
>> Without going into any further details, maybe someone out there
has
>> already "been there, done that" and has some advice/direction?
>
>(Hope you brought your lunch for this answer.)
>
>Been there, done that.
>
>Last winter I purchased a front suspension software package and
spent many
>hours trying to find a way to provide negative camber and improve
the front
>end geometry in a practical manner, using stock suspension pieces
and
>pivots. Maybe someone out there has come up with a nice
improvement, but I
>have not. However, I have successfully provided parts for 1-1/2
deg negative
>camber for a number of Triumphs.
>
>There are three ways to do this that I know of, each with pro's
and cons. I
>hope that someone who has implemented a better solution than what
I'll
>describe will chime in and add to our collective knowledge.
>
>One method is to weld internally threaded receptacles to the
upper a-arms in
>place of the current inboard ends, and install Heim joints. It
has pros and
>cons that you can imagine, one of the cons being that it's
illegal in most
>vintage circles to put a Heim joint there, so I won't do it.
>
>A second way is to bolt a piece of angle iron to the top of the
front tower
>where the trunion is now bolted. Then you turn the top trunion 90
deg and
>bolt it to the vertical leg of the angle iron, providing
opportunity to shim
>between the trunion and the angle iron, for adjustability. There
is at least
>one TR in the midwest using this approach and it is successful. I
like that
>idea, exept it requires either raising the pivot axis of the
inner trunion
>which makes theoretically undesirable changes in the dynamics of
the front
>suspension geometry, or else you cut off two of the trunnion ears
to get the
>pivot line in about the right vertical position but that leaves
only two of
>those little ears holding the top trunion on, which makes me
nervous.
>
>The third way is one that I've either done myself or provided
parts for, now
>installed on maybe ten TR's that I know of. It is not an original
idea, lest
>anyone should be offended.
>
>This involves using TR4 upper a-arms and shortening them.
>
>For a TR4, This is pretty straightforward. You use all the stock
suspension
>members, saw a section out of the upper a-arms, and weld them
back together
>in a safe manner. I Mig weld them and then weld another piece of
steel to
>the open side of the c-section, thus boxing in the joint, just
for safety's
>sake.
>
>For a TR3, you replace your current upper a-arms, upper ball
joints, and
>vertical link with TR4 parts. This gives you the TR4 caster
angle, and it
>gives you upper a-arms that are more easily shortened.
>
>The obvious disadvantage of this method is lack of adjustability.
That, plus
>you must saw the right amount out of the upper a-arm, and that
amount varies
>with the amount that you have lowered your front suspension.
>
>The combination that we're using on TR4's, and that should work
on TR3's, is
>to
>
>1) Remove the upper aluminum spring spacer block
>2) install MGBGT front springs which are 480 lb / in, more or less
>3) shorten upper a-arms by 3/8"
>
>This gives 1-1/2 degrees negative camber (if nothing else up
front is bent).
>
>I have built a weld fixture to hold the parts exactly right and
have made a
>number of sets of these upper arms for friends. It's very time
consuming. If
>interested, contact me off-list.
>
>Hope everyone has finished their lunch.
>
>
>
>
>--
>
>uncle jack and New Blue
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