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RE: Steering Question

To: FOT <FOT@autox.team.net>
Subject: RE: Steering Question
From: Bill Babcock <BillB@bnj.com>
Date: Fri, 30 Apr 1999 11:18:15 -0700
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Long tie rod ends will definitely slow down the steering--but they were
probably also looking for reduced steering effort. If you want to quicken
your steering you should probably use the short ones. But short ends will
also exacerbate bump steer since the relative movement will be greater for
any bump-induced steering input. 

I don't know about the TR4, but my TR3 steering geometry responded well to a
few simple modifications--moving the steering box up about 1/2" and forwards
1/2" reduced the bump steer substantially. I moved the idler forward 3/4"
and bent the arm so the attachment point wound up in the same location as
the steering arm(1/2" forward, 1/2" up). This--according to the computer
program I was using--is the minimum bump steer position for my modified
suspension. (longer adjustable upper arms, upper pivot point moved inboard 1
1/2").

Obviously that's not a formula--your mileage will vary--but shooting for
minimum bump steer and a reasonable roll center worked wonders for my car. 

-----Original Message-----
From: Irv Korey [mailto:emanteno@ibm.net]
Sent: Friday, April 30, 1999 4:48 AM
To: FOT
Subject: Steering Question


Good morning, FOT.

My car started life as a 66 TR4A solid axle. During its earlier life as a
SCCA EP car, much of the car was replaced including the frame, with the
frame from a TR4. Today, there is a mix of TR4 and 4A parts in the car,
including the front suspension.

Jack Drews noticed that my tie rod levers seemed too long, the tie rod ends
seemed to be angled towards the front of the car at a significantly greater
angle than the ones on his car. Last night, I looked at the Bentley for 4's
and 4A's, and found that the TR4 tie rod lever was approximately 5.6" long,
while the TR4A tie rod lever was 7.18" long. 

Jack's theory is that Triumph may have wanted to slow down the steering on
the 4A's, perhaps due to possible complaints of twitchiness on the earlier
cars? As I prepare the car for its first real return to the track in 14
years, is there an advantage to one of these tie rod levers versus the
other? All opinions, thoughts, theories, graciously accepted.

Thanks as always.

Irv Korey
Highland Park, IL
74 TR6 CF22767U
TR4A CT52499 (almost ready vintage racer)

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<TITLE>RE: Steering Question</TITLE>
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<P><FONT SIZE=3D2>Long tie rod ends will definitely slow down the =
steering--but they were probably also looking for reduced steering =
effort. If you want to quicken your steering you should probably use =
the short ones. But short ends will also exacerbate bump steer since =
the relative movement will be greater for any bump-induced steering =
input. </FONT></P>

<P><FONT SIZE=3D2>I don't know about the TR4, but my TR3 steering =
geometry responded well to a few simple modifications--moving the =
steering box up about 1/2&quot; and forwards 1/2&quot; reduced the bump =
steer substantially. I moved the idler forward 3/4&quot; and bent the =
arm so the attachment point wound up in the same location as the =
steering arm(1/2&quot; forward, 1/2&quot; up). This--according to the =
computer program I was using--is the minimum bump steer position for my =
modified suspension. (longer adjustable upper arms, upper pivot point =
moved inboard 1 1/2&quot;).</FONT></P>

<P><FONT SIZE=3D2>Obviously that's not a formula--your mileage will =
vary--but shooting for minimum bump steer and a reasonable roll center =
worked wonders for my car. </FONT></P>

<P><FONT SIZE=3D2>-----Original Message-----</FONT>
<BR><FONT SIZE=3D2>From: Irv Korey [<A =
HREF=3D"mailto:emanteno@ibm.net";>mailto:emanteno@ibm.net</A>]</FONT>
<BR><FONT SIZE=3D2>Sent: Friday, April 30, 1999 4:48 AM</FONT>
<BR><FONT SIZE=3D2>To: FOT</FONT>
<BR><FONT SIZE=3D2>Subject: Steering Question</FONT>
</P>
<BR>

<P><FONT SIZE=3D2>Good morning, FOT.</FONT>
</P>

<P><FONT SIZE=3D2>My car started life as a 66 TR4A solid axle. During =
its earlier life as a</FONT>
<BR><FONT SIZE=3D2>SCCA EP car, much of the car was replaced including =
the frame, with the</FONT>
<BR><FONT SIZE=3D2>frame from a TR4. Today, there is a mix of TR4 and =
4A parts in the car,</FONT>
<BR><FONT SIZE=3D2>including the front suspension.</FONT>
</P>

<P><FONT SIZE=3D2>Jack Drews noticed that my tie rod levers seemed too =
long, the tie rod ends</FONT>
<BR><FONT SIZE=3D2>seemed to be angled towards the front of the car at =
a significantly greater</FONT>
<BR><FONT SIZE=3D2>angle than the ones on his car. Last night, I looked =
at the Bentley for 4's</FONT>
<BR><FONT SIZE=3D2>and 4A's, and found that the TR4 tie rod lever was =
approximately 5.6&quot; long,</FONT>
<BR><FONT SIZE=3D2>while the TR4A tie rod lever was 7.18&quot; long. =
</FONT>
</P>

<P><FONT SIZE=3D2>Jack's theory is that Triumph may have wanted to slow =
down the steering on</FONT>
<BR><FONT SIZE=3D2>the 4A's, perhaps due to possible complaints of =
twitchiness on the earlier</FONT>
<BR><FONT SIZE=3D2>cars? As I prepare the car for its first real return =
to the track in 14</FONT>
<BR><FONT SIZE=3D2>years, is there an advantage to one of these tie rod =
levers versus the</FONT>
<BR><FONT SIZE=3D2>other? All opinions, thoughts, theories, graciously =
accepted.</FONT>
</P>

<P><FONT SIZE=3D2>Thanks as always.</FONT>
</P>

<P><FONT SIZE=3D2>Irv Korey</FONT>
<BR><FONT SIZE=3D2>Highland Park, IL</FONT>
<BR><FONT SIZE=3D2>74 TR6 CF22767U</FONT>
<BR><FONT SIZE=3D2>TR4A CT52499 (almost ready vintage racer)</FONT>
</P>

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