Boy, that'd do it. I can change the caster on my TR3, because I made the
upper arm from two adjustable links that connect to a Rose (Heim) joint.
for more or less camber you turn both links, to change caster you turn one
in and the other out. I don't recall what I set that at, but I measured
the trail at about an inch at rest. Trail may be more of a motorcycle
term, it's the distance between the center line of the upright and the
contact patch of the tire. It's directly proportional to caster.
When I simulated my suspension on the computer I noticed that Caster
changes a little as the suspension moves. That's not really supposed to
happen, but the difference in upper and lower arm length seems to cause
it. Lengthening the upper arm reduced the change.
-----Original Message-----
From: Kas Kastner [mailto:kaskas@earthlink.net]
Sent: Wednesday, April 03, 2002 3:27 PM
To: Bill Babcock; 'John Herrera'; fot@autox.team.net
Subject: Re: Wandering TR3
The early TR-3's had zero caster and when under had braking this will
cause
you to leap and wiggle over three lanes. Worth checking out. (yes, you
want
more caster)
----- Original Message -----
From: "Bill Babcock" <BillB@bnj.com>
To: "'John Herrera'" <jherrera@fcc.cc.md.us>; <fot@autox.team.net>
Sent: Wednesday, April 03, 2002 1:00 PM
Subject: RE: Wandering TR3
> Ooh, a typical problem. People used to say my TR3 was twitchy at the end
> of the straight, just because it would occasionally jump ten feet in one
> direction or another. If you're in the lead with a bunch of expensive
cars
> behind you it can be a real advantage.
>
> I mellowed my car out by softening the rear springs. a rear roll bar
will
> also make the back wheels steer more, and that's another good reason for
> not having one.
>
> Triumphs all have a lot of bump steer, so that may be part of the
problem,
> but not likely if your front springs are stiff enough (most TR3's don't
> bounce around that much).
>
> You have to do a lot of work to really get TR3s to handle and stop
> darting, most of which has been discussed at length. I suggest you
search
> the archives
>
> You probably want a little toe in. Toe out will definitely make the car
> leap around, neutral is probably almost as bad. I don't remember what I
> used, but it seems like it was a fair amount--maybe 1/2" measured at the
> tires, front to back. I know that's kind of rough, should be in degrees
> and all that, but I use an aluminum bar with stands and right-angle ends
> to do my measuring. Sometimes just string. But I make up for it with a
> really cool Camber gauge.
>
> Hello All:
>
> I got the TR3 race car out of the falling down shed to move it to the
> "garage" shed so I can work on it for Mid-Ohio. Some mice are looking
> for their home. I drove the car on the road a little.
>
> The Darting Around Without Driver Input is worse than I remember it
> being. I have to constantly make steering corrections. The blue TR3
> feels like it's on
> rails compared to the race car.
>
> John Hornbostel, do you remember when this started or did it always do
> it?
>
> Is it bump steer? I am not aware of the darting being connected to
> hitting a bump, but it might be.
>
> Is there a fix or is it the kind of thing we just live with?
>
> It seems that it wasn't so bad in the driver's schools as it is on the
> road. adrenalin?
>
> The front suspnsion has lowered springs, Delrin bushings, and a 7/8"
> sway bar. I think it's stock otherwise. Could the lowering cause bump
> steer?
>
> The car had lots of toe-out when I got it. I set it for zero toe-in
> myself with a bar I got from Moss. It didn't seem to help much. I could
> have screwed it up.
> Any help would be greatly appreciated.
>
> John Herrera
|