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Are composite leaf springs worth it on a street ride?

  • Thread starter Thread starter danza
  • Start date Start date Aug 4, 2005
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ashford

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Dec 19, 2003
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fargo ND
Aug 8, 2005
#21
  • Aug 8, 2005
  • #21
the early g-body(lumina, cutlass supreme,etc) gms had a single composite spring in the rear
 
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66bluepony

New Member
Nov 7, 2004
75
1
0
Aug 11, 2005
#22
  • Aug 11, 2005
  • #22
Springs

Boo Boo Foo said:
I fitted a set of Flex-a-Form composite leaf springs to my 66 Fastback last January. At the same time, I also fitted a new 3.55 ring and pinion, a new Currie Limited Slip Diff and a new Currie Aluminum Third Member, and a new aluminum driveshaft, a new set of Koni shocks, and a new set of heavy duty rear shackles with delalum bushings... Obviously a lot of stuff changed in one fell swoop, but I can honestly say that the difference in handling in the rear end is breathtaking. The leafs are so light that the rear axle assembly lost almost 120 pounds in unsprung weight. The handling improved out of sight. Pliable, and ultra smooth yet wonderfully predictable and stiff when needed.

My best investment yet, suspension wise. I also own a Lexus ES300 with a nice IRS and the Mustang is probably 90% as stable (in the rear) I would venture to say. I have a few local undulations and bumps around my local streets that I use to do these sort of comparisons - and those composite leafs really are that good.
Click to expand...

What specs did you ask for in spring weight as far as supporting the rear of car.
 

Edbert

Founding Member
Jul 13, 2002
3,548
32
109
Austin TX
www.edbert.net
Aug 11, 2005
#23
  • Aug 11, 2005
  • #23
I'd say 200-225 depending on your preference for stiffness and the type of rear end you have, maybe even 250 for a road racer with a 9. At least that is for conventional steel springs...I assume they would work the same way in that regard.
 
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66bluepony

New Member
Nov 7, 2004
75
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Aug 12, 2005
#24
  • Aug 12, 2005
  • #24
Weight

I have been told that 225 lbs have a lot of bounce. That is why I was asking what Boo Boo Foo used. But I think that Edbert is in the ballpark.
 

brianj5600

Active Member
Sep 19, 2003
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Middle TN
www.cardomain.com
Aug 12, 2005
#25
  • Aug 12, 2005
  • #25
Opentracker said:
Click to expand...
What is the ride height like for them? Are the eyes bonded, or just bolted? I am wondering if eyes can be easily changed or flipped for ride height adjustments.
 

70vert

New Member
Dec 31, 2004
722
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Bay Area, CA
Aug 13, 2005
#26
  • Aug 13, 2005
  • #26
wait, do you mean slider mounts?

10secgoal said:
You like those springs, wait until you find out what raoller perches are.
Click to expand...

roller perches are for front suspension, are you thinking about slider mounts for the rear a la what is sold by Cobra Automotive?
 

70vert

New Member
Dec 31, 2004
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Bay Area, CA
Aug 13, 2005
#27
  • Aug 13, 2005
  • #27
thread on corner-carvers

Hey all,
Check out this thread on corner-carvers.com:

http://www.corner-carvers.com/

and just type in "composite leaf springs" in the search and you'll find it. Boo Boo is there, and it's good reading - too much to summarize. I am now seriously thinking about these and a Maier panhard down the road.
 
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10secgoal

Active Member
Dec 1, 2003
2,801
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San Diego
Aug 13, 2005
#28
  • Aug 13, 2005
  • #28
70vert said:
roller perches are for front suspension, are you thinking about slider mounts for the rear a la what is sold by Cobra Automotive?
Click to expand...
I know the roller perches are for the front. That's what I mean. Those change the ride of the car some much it's unreal. I don't know how much a composite can change the ride, but it seems hard to beat freeing up the ENTIRE front end.
 

Taranis

New Member
Nov 12, 2004
92
1
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Austin, Texas
Oct 23, 2005
#29
  • Oct 23, 2005
  • #29
Does anybody know what happened to flex a form?
I tried www.flex-a-form.com and the domain name expired...
 

atomicpunk

Member
May 15, 2005
80
0
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Rocky Mountains
Oct 24, 2005
#30
  • Oct 24, 2005
  • #30
I guess they goofed and lost the domain. They're still around, I just received a set of leafs from them a couple of weeks ago.

I have their number as 864-261-7006
 

Taranis

New Member
Nov 12, 2004
92
1
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Austin, Texas
Oct 24, 2005
#31
  • Oct 24, 2005
  • #31
Sweet. Thanks for the info.
 

Tubo(2-bo)

Member
Mar 25, 2004
279
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16
Ft Walton Beach FL.
Oct 25, 2005
#32
  • Oct 25, 2005
  • #32
I understand, though only from articles I've read, that the composite springs have no wrap up, and traction bars are not needed. So there's a little more weight saved. I had the impression about 80lb. was saved using composits, and wondered if the loss of weight in the rear of the car would have a negative effect on handling & traction.
If your building from scratch, the money saved on traction bars could be rolled into the cost of the composite springs.
 
S

SNAKEPILOT

New Member
Jul 8, 2005
112
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Dec 23, 2005
#33
  • Dec 23, 2005
  • #33
Boo Boo Foo,
Did you use Global West Delalum bushings in your Flex-a-forms? Is the bushing diameter the same as the original leafs?
 

atomicpunk

Member
May 15, 2005
80
0
6
Rocky Mountains
Dec 25, 2005
#34
  • Dec 25, 2005
  • #34
Someone posted elsewhere that GW recommended against using their bushings in composite springs.

I went with Mustang Depot's Prothane HD shackle kit instead. The Flex-A-Forms had bushings that were the same as the original diameter. In my case, they reversed them front and rear, and the instructions said "do not remove the bushings". However, they finally got back to me and in his usual cryptic 3 word emails, George indicated swapping them wasn't an issue, but couldn't clarify why they said not to remove them.
 

rbohm

Founding Member
Apr 12, 2002
6,698
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tucson,az
Dec 26, 2005
#35
  • Dec 26, 2005
  • #35
http://flex-a-form.com/Default.asp
 
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