In a message dated 4/16/98 10:38:50 PM Pacific Daylight Time, BillB@bnj.com
writes:
<<The bump steer with a
stock front suspension is just scary. >>
I always wanted to measure the bump steer on a completely stock TR3. I went
to check my street TR3A and found that despite it looking all unraced
original,
the vertical links had been carefully bent to reduce the positive camber.
After I had realigned my race car to 3 dig caster and 1 5/8 neg camber, it was
difficult to set the toe on a less than flat surface. It still had the TR3
steering
system. It turned out that I had been running bump steer of MAJOR
proportions:
At 2" of upward wheel travel it toed in 1.2" What was a tad eye opening going
into the Road Atlanta dip with race tires was 1.7" toe OUT on two inches of
downward wheel travel!
I found that the TR4A steering arms bent up 1.2" prox. fixed the bump steer
to
within a few thow. The problem is that they slow the steering down a lot. I
fitted a smaller steering wheel.
When I could finally legally fit a rack, I had a TR4 rack shortened to keep
the inner tie rod joints in the same place as the TR3 center tie rod had
them, as I knew that this would work for MY car's caster and camber.
The rack was shortened all on the offside end, with new OD threads and
the recess in the end. The Hsg. was also shortened on the same end,
with the counter bore for the rack bush slightly undersize to cover wear in
the bush!
The first set of brackets to hold the rack to the frame lower cross member
were
heavy, but still deflected too much. I welded added mounts to the frame
bolt in cross member. I cannot believe how flimsy the early TR4 factory
rack mounts look.
I also had to make a tiny steering wheel as the TR4 rack is much slower
than the TR3 box.
Regards, HP
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