You can get caster with a trunnion without binding by either changing the
angle of the lower mount and moving the upper mount back to meet the new
location of the upper ball joint (hard) or by building it into the link.
My guess is that the late TR4 built it into the link and that WOULD result
in caster angle being different from the kingpin angle and might induce a
little shake.
I had about three degree of caster dialed in just by moving the upper
mount and forcing the trunnion. I never detected any binding in use, and
no real force that I could detect (or remember) was involved in moving the
upper balljoint--I did it by adjusting my (illegal) modified A arm
unequally. But when I was measuring everything lately I checked bump steer
directly in my TR3 and found binding at the top and bottom of the
suspension travel, as well as near the stops for full steering travel.
I will probably stick the later parts in Peyote as part of my Don Quixote
journey to better handling through computer simulation, now known as the
winter project that never ended.
-----Original Message-----
From: riverside
To: fot
Sent: 3/12/2003 2:25 PM
Subject: bj's
Three degrees caster is better than 0 but not nearly as good
as 4.5 to 5. I don't see how yuo can get at the top what is
not allowed at the bottom without some bind.
I have read that if your caster is greater than the king pin
inclination,
nasty vibrations can occur. Don't know why
and my best suspension engineer friend is ignoring my
pleas for an answer!
My old friend and mentor Bill Boemler told me that once he
had a combination of bits that yielded something like 10
degrees caster on his TR3. Said it cornered fantastic, but after
a few laps his arms fell off. The circle track guys say "caster
makes you faster".
art d
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