Tri-link Conversion

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fp55scca
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Tri-link Conversion

Post by fp55scca » Mon Jun 09, 2014 3:54 pm

--Finally got around to a conversion from 4 trailing arms on my racecar to
three arms, plus the panhard bar in stock location. This popular tri-link
conversion for a live axle car is intended to improve roll center of the rear
axle, giving better tire contact in hard cornering.

--The conversion eliminates the two short upper-arms, and replaces them
with a single trailing arm that attaches to the top center of the differential
at the rear, and to a forward bracket inside the car. The 3 links are equal
length and parallel. All links are heim-jointed on both ends (for now). In
my installation, I tied the forward bracket into the rollcage, and added a
final forward brace for good measure.

http://i155.photobucket.com/albums/s308/Jfscurria/Diff-
Bracketfor3rdLink_zps8585e6b3.jpg

http://i155.photobucket.com/albums/s308 ... or3rdLink-
1_zpsab5448ed.jpg

http://i155.photobucket.com/albums/s308 ... nk_zps1d67
a460.jpg

http://i155.photobucket.com/albums/s308 ... ia/Final3-
LinkSuspension_zpsda7f7379.jpg

Jim


72 Spider - owned since July '73
74 Spider - CSA project/daily driver
72 Spider - SCCA FP 24
68 Spider - parts car
Jim Scurria
Norfolk, VA

1972 Fiat 124 Spider
1971 Spider - SCCA FP-24
1974 Fiat 124 Spider
fiatmac
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Last Name: McConnell
First Name: Stan

Re: Tri-link Conversion

Post by fiatmac » Mon Jun 09, 2014 4:05 pm

Photobucket says these photos have been deleted!

Jim Scurria wrote:
: --Finally got around to a conversion from 4 trailing arms on my racecar to
: three arms, plus the panhard bar in stock location. This popular tri-link
: conversion for a live axle car is intended to improve roll center of the rear
: axle, giving better tire contact in hard cornering.
: --The conversion eliminates the two short upper-arms, and replaces them
: with a single trailing arm that attaches to the top center of the differential
: at the rear, and to a forward bracket inside the car. The 3 links are equal
: length and parallel. All links are heim-jointed on both ends (for now). In
: my installation, I tied the forward bracket into the rollcage, and added a
: final forward brace for good measure.
: http://i155.photobucket.com/albums/s308/Jfscurria/Diff-
: Bracketfor3rdLink_zps8585e6b3.jpg
: http://i155.photobucket.com/albums/s308 ... or3rdLink-
: 1_zpsab5448ed.jpg
: http://i155.photobucket.com/albums/s308 ... nk_zps1d67
: a460.jpg
: http://i155.photobucket.com/albums/s308 ... ia/Final3-
: LinkSuspension_zpsda7f7379.jpg
: Jim
:
: 72 Spider - owned since July '73
: 74 Spider - CSA project/daily driver
: 72 Spider - SCCA FP 24
: 68 Spider - parts car
Stan McConnell
Retired engineer
Salisbury, NC
82 2000 Spider
78 124 Spider on the rotisserie
fp55scca
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Re: Tri-link Conversion

Post by fp55scca » Mon Jun 09, 2014 4:40 pm

--Sorry about the wrap-around links Stan, you have to copy and paste the
full link into your browser....I'm lazy and didn't make tiny-url's.

72 Spider - owned since July '73
74 Spider - CSA project/daily driver
72 Spider - SCCA FP 24
68 Spider - parts car
Jim Scurria
Norfolk, VA

1972 Fiat 124 Spider
1971 Spider - SCCA FP-24
1974 Fiat 124 Spider
fp55scca
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Tiny-URL's

Post by fp55scca » Mon Jun 09, 2014 9:35 pm

--Ok guys, here's some tiny url's:

http://tinyurl.com/njb52vn

http://tinyurl.com/qe489c9

http://tinyurl.com/ml78ceu

http://tinyurl.com/pnpxkz3

Jim

72 Spider - owned since July '73
74 Spider - CSA project/daily driver
72 Spider - SCCA FP 24
68 Spider - parts car
Jim Scurria
Norfolk, VA

1972 Fiat 124 Spider
1971 Spider - SCCA FP-24
1974 Fiat 124 Spider
audiophile22
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Re: Tiny-URL's

Post by audiophile22 » Mon Jun 09, 2014 10:04 pm

Jim Scurria wrote:
: --Ok guys, here's some tiny url's:
: http://tinyurl.com/njb52vn
: http://tinyurl.com/qe489c9
: http://tinyurl.com/ml78ceu
: http://tinyurl.com/pnpxkz3
: Jim
: 72 Spider - owned since July '73
: 74 Spider - CSA project/daily driver
: 72 Spider - SCCA FP 24
: 68 Spider - parts car
mona
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Re: Tri-link Conversion

Post by mona » Tue Jun 10, 2014 8:32 am

Jim, do you do your own welding, the installation looks really clean and the
welds look super.


carl in Virginia

73 spider
79 spider
fp55scca
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Re: Tri-link Conversion

Post by fp55scca » Tue Jun 10, 2014 10:15 am

Carl Friedman wrote:
: Jim, do you do your own welding,
--------------------------------------------
--Carl, I do most, but not the critical welds. The bracket on top of the
differential involved two very different thicknesses, so I passed that to a
pro. As you know, too much heat can cause the metal to become brittle, and I
couldn't chance that.
Jim

72 Spider - owned since July '73
74 Spider - CSA project/daily driver
72 Spider - SCCA FP 24
68 Spider - parts car
Jim Scurria
Norfolk, VA

1972 Fiat 124 Spider
1971 Spider - SCCA FP-24
1974 Fiat 124 Spider
User avatar
engineerted
Posts: 370
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Last Name: Ted
First Name: Russell

Re: Tri-link Conversion

Post by engineerted » Fri Jun 20, 2014 10:18 am

Jim,

Here is photo from a Huffaker Spridget, This is how you get the rear roll
center realy close to the ground. WOW.
http://img.photobucket.com/albums/v95/e ... da1d6b.png

TED
1978 124 steet car
1974 124 EProd race car
Farmington Hills, MI
fp55scca
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Re: Tri-link Conversion

Post by fp55scca » Fri Jun 20, 2014 11:16 am

--Ted, it took me a minute to even understand how that works, but I finally
got it. This also eliminates the panhard bar. Very cool....and we call
this "production" racing!
Jim


72 Spider - owned since July '73
74 Spider - CSA project/daily driver
72 Spider - SCCA FP 24
68 Spider - parts car
Jim Scurria
Norfolk, VA

1972 Fiat 124 Spider
1971 Spider - SCCA FP-24
1974 Fiat 124 Spider
User avatar
engineerted
Posts: 370
Joined: Sun Jan 24, 2016 11:22 am
Last Name: Ted
First Name: Russell

Re: Tri-link Conversion

Post by engineerted » Fri Jun 20, 2014 3:18 pm

Jim,

You may have seen this one before, This is the lotus style as fitted to the
Fiat.

http://img.photobucket.com/albums/v95/e ... a73122.png
1978 124 steet car
1974 124 EProd race car
Farmington Hills, MI
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