Tigers,
For those of you considering modification to the Tiger steering
geometry, I ran across a message
describing the actual experience of some very knowledgeable Tiger
people, who shall remain
anonymous for personal reasons.
I believe their "lessons learned" should be of interest to anyone
contemplating steering geometry
change.
On behalf of A. Nony Mouse, and friend:
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With the help of a friend, we made a fixture to hold the front
cross member up at a good working height.
We set up the front end as I would on a road race tiger. Stock parts with
some tweaking!
We locked down the hubs and clamped long angel irons to the rotors to
measure toe changes.
Here is what we found:
- ackerman problems come into play as you enter the last half turn of the
steering wheel.
With basically 1 1/2 turns from center to full lock, you will rarely
get into the last 1/2 turn on a road race track.
We consistently had better ackerman than the shop manual says,
attributed to the race settings.
- The standard bump steer is as good as it is going to get, with a ride
height anywhere close to standard.
You can change bump steer, but it is a compromise! You gain here and
lose there! The Rootes engineers did a good job with what they had to
work with!
If you install the MGB arms alone, the bump steer changes, and not in a
good way! The tie rods are not at the correct height.
If you install a midget rack and MGB arms, several things change.
Bump steer goes off (bad) because the rack has different dimensions
and effective arm lengths and the tie rods are at the wrong height.
To correct the problems with a Midget rack and MGB arms you need to
lower the rack more than you can with the standard Tiger cross member!
- the midget rack appears to fix the ackerman only to the extent of
limiting the travel from lock to lock.
You simply can not get into as much of a problem with a Midget rack.
Don't turn your standard Tiger rack to full lock and you have reduced the
ackerman problem!
The midget rack typically feels better because it has less friction
and simply turns easier.
Regards,
A. Nony Mouse, and friend
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I have found that steering problems become extreme, with a stock system,
in a near full lock reverse turn. I recommend a few maneuvers with less
steering angle.
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Steve Laifman
Editor
http://www.TigersUnited.com
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