1 Topic by gunn (edited by gunn 2011-03-17 11:24 AM)

  • gunn
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Topic: Q: Looking for insights on using other vehicles springs on my 95 Tbird

Hi:
I'm moving onto the suspension research now and while the front-running recommendation is to find Tbird Super Coupe springs and cut them, I was wondering if you guys might be able to shed some light on alternatives because I'm still looking for a set of SC springs at a reasonable price.

I know some other folks here have said just to go "find a truck at a junkyard and put them on" but I'm curious to find out what tolerances I might have to deal with.

Here's what I know:

Specs on my Current Springs
Front Spring
    Inside Diameter=3.677"
    Wire Diameter=.656"
    Free Height=16.88"
    Load height=14"

    Front: 223-282 lb./in.

Rear Spring
    Inside Diameter=4.26"
    Wire Diameter=.703"
    Free Height=12.81"
    Load height=11"

    Rear: 361-501 lb./in.

Specs on the SC springs I'm looking for...
Front: 349-403 lb./in.
Rear: 509-637 lb./in.
When I cut them the spring rate should shift towards the upper end of this range.

Plans for the car
Even though my choice of tire should drop the car 1.5", I calculate that my new ride height with my existing spring set will be 6" in the front and 7" in the rear -- plenty of room to cut -- thanks to the >380LBs we've removed from this pig.

Questions...
Q: If I look at another vehicle, I know that the inside diameter of the target spring must be at LEAST 3.67" in the front and 4.26" in the rear.

Q: How much bigger can they be though? What's my limiting factor -- the size of the upper mount, right?

Q: Is there anything else I should worry about (like spring ends even though I'm likely to cut at least one of them?)

Ahh, lookie what I found here. Listing of Moog Coil Specifications (can use to cross reference what cars to look for at the junkyard.
http://classiccarsprings.com/coil-sprin … tions.html

After filtering out the data, I found this items.
In this chart, my tbird spring ratings are listed as
Front CC871 - spring rate 290lb/in
Rears CC861 - spring rate 418lb/in

My closest match to the inner diameters that would be an upgrade off the specs above would be the following:
FRONT (assuming less than the rears) - model # 6452
  Inner Dia 3.68"
  Wire 0.78"
  Load Height 10"
  Load Capacity     3155
  Spring Rate 843
  Free Length 13.64
   CHEVROLET    BLAZER    (1973 - 1983)
   CHEVROLET    C10 PICKUP    (1973 - 1986)
   CHEVROLET    C10 PICKUP BIG TEN    (1978 - 1980)
   CHEVROLET    C10 SUBURBAN    (1973 - 1983)
   CHEVROLET    C20 PICKUP    (1973 - 1986)
   CHEVROLET    C20 SUBURBAN    (1979 - 1983)
   CHEVROLET    C30 PICKUP    (1977 - 1981)
   CHEVROLET    G10 SPORTVAN    (1973 - 1993)
   CHEVROLET    G10 VAN    (1973 - 1995)
   CHEVROLET    G20 SPORTVAN    (1973 - 1995)
   CHEVROLET    G20 VAN    (1973 - 1995)
   CHEVROLET    K5 BLAZER    1976
   CHEVROLET    P10 VAN    (1973 - 1980)
   CHEVROLET    R10 PICKUP    1987
   CHEVROLET    R20 PICKUP    1987
   GMC    C15 PICKUP    (1975 - 1978)
   GMC    C15 PICKUP BIG TEN    (1977 - 1978)
   GMC    C15 SUBURBAN    (1977 - 1978)
   GMC    C15/C1500 PICKUP    (1973 - 1974)
   GMC    C1500 PICKUP    (1979 - 1986)
   GMC    C1500 PICKUP BIG TEN    (1979 - 1980)
   GMC    C1500 SUBURBAN    (1979 - 1986)
   GMC    C25 PICKUP    (1975 - 1978)
   GMC    C25 SUBURBAN    (1977 - 1978)
   GMC    C25/C2500 PICKUP    (1973 - 1974)
   GMC    C2500 PICKUP    (1979 - 1986)
   GMC    C2500 SUBURBAN    (1979 - 1983)
   GMC    C35 PICKUP    (1977 - 1978)
   GMC    C3500 PICKUP    (1979 - 1981)
   GMC    G15 VAN RALLY    (1975 - 1978)
   GMC    G15 VANDURA    (1975 - 1978)
   GMC    G15/G1500 VAN RALLY    (1973 - 1974)
   GMC    G15/G1500 VANDURA    (1973 - 1974)
   GMC    G1500 VAN    (1983 - 1995)
   GMC    G1500 VAN RALLY    (1979 - 1993)
   GMC    G1500 VANDURA    (1979 - 1995)
   GMC    G25 VAN RALLY    (1975 - 1976)
   GMC    G25 VANDURA    (1975 - 1976)
   GMC    G25/G2500 VAN RALLY    (1973 - 1974)
   GMC    G25/G2500 VANDURA    (1973 - 1974)
   GMC    G2500 VAN RALLY    (1992 - 1995)
   GMC    G2500 VANDURA    (1992 - 1995)
   GMC    JIMMY    (1973 - 1983)
   GMC    P15 VAN    (1975 - 1978)
   GMC    P15/P1500 VAN    (1973 - 1974)
   GMC    P1500 VAN    (1979 - 1980)
   GMC    R1500 PICKUP    1987
   GMC    R1500 SUBURBAN    (1987 - 1991)
   GMC    R2500 PICKUP    1987

REAR - Model # CC615
  Inner Dia 5.2"
  Wire 0.94
  Load Height 10.75"
  Load Capacity    1335   
  Spring Rate 820   
  Free Length 12.38
  From
    CHEVROLET    C20 PICKUP    (1963 - 1972)
    GMC    C25/C2500 PICKUP    (1969 - 1972)


Q: Do you think these would work for my application (assuming I can find these vehicles in a scrapyard)?

Q: Or, am I just over thinking this and should I just cut the springs already on the car and be done with it?

Thanks again for your advice.
-g

Myopic Motorsport's #888 Ceci n'est pas une Citron Thunderbird ("This is not a lemon" but a 1995 tbird w/ 93 V8 swap + shopping cart rear wing + engine mounted frito maker)
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  • From: Baltimore, MD
  • Registered: 2010-05-20
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Re: Q: Looking for insights on using other vehicles springs on my 95 Tbird

A1: If you can't find those vehicles in a scrapyard, you aren't looking hard enough. That's nearly every truck GM produced for 20 years and they produced BILLIONS of them. I drove a G25 Vandura. Those springs are MONSTERS. I can only imaging putting them under a lightweight car would be akin to building your suspension out of bricks.

Oddly enough, I think I have some springs for that van out in the shed. The van is long gone, so if you want 'em, I'm sure we can work something out.

A2: Personally, I'd cut what you have and see what happens.

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  • From: Lost in the Rockies
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Re: Q: Looking for insights on using other vehicles springs on my 95 Tbird

It looks like you've done most of your homework, but have you read the informative page on MotoIQ from Eyesore Racing (Frankenmiata)? It might help you double-check your work.
http://www.motoiq.com/magazine_articles … cksaw.aspx

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  • From: Central CT
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Re: Q: Looking for insights on using other vehicles springs on my 95 Tbird

Where did you find the cross-reference for what cars each spring fits?     I was planning to go to a junkyard with a pair of calipers, and a calculator, and the spring rate formula to select springs.

Knowing what vehicle i'm looking for would be so much better

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5 Reply by frankdtank00 (edited by frankdtank00 2011-03-17 02:15 PM)

  • Registered: 2011-01-04
  • Posts: 209

Re: Q: Looking for insights on using other vehicles springs on my 95 Tbird

Moog spring book can be found at any good parts store (thats what i use). it has all dimensions, load, sring rate, free height and ride height.

from what i found for the Dodge shelby daytona charger is 86-95 ford taurus front springs and 79-93 mustanf rear spring and a lil bit of cutting.

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  • From: Central CT
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Re: Q: Looking for insights on using other vehicles springs on my 95 Tbird

The vehicle listing that gunn posted looks like something that was copied and pasted in, not anything he typed in by hand.    I was hoping for a link to wherever he got that data from.

Maximum Effort Motorsports - Mid-engine 1979 Chevette - Class C Winner - GP Du Lac Chargoggagoggmanchauggagoggchaubunagungamaugg
New England Long Winter Build Award - 2015
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Class C & Least Horrible Yank Tank winner - Boston Tow Party & Overhead Cam Bake 2011
  • From: Brandywine, MD
  • Registered: 2009-07-15
  • Posts: 4,528

Re: Q: Looking for insights on using other vehicles springs on my 95 Tbird

I used Vogtland 1.6" drop springs. Worth every penny. If you have room in the residual value budget, do it.

Captain: Speedycop & The Gang Of Outlaws -'94 Mark VIII (Least Horrible Yank Tank Stafford '09, NOLA '10) '61 Caddy (Org Choice-NL '09) '63 Tbird (EPIC Repair Failure-Gingerman '10, I Got Screwed-Summit Pt '10, I.O.E. WINNER Stafford '10!) '77 Lancia Scorpion (I.O.E. WINNER Joliet 2010!) '67 Galaxie 500 (Judges Choice-CMP '11)
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8 Reply by gunn (edited by gunn 2011-03-23 09:29 AM)

  • gunn
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Re: Q: Looking for insights on using other vehicles springs on my 95 Tbird

mike944 wrote:

Where did you find the cross-reference for what cars each spring fits?     I was planning to go to a junkyard with a pair of calipers, and a calculator, and the spring rate formula to select springs.

Knowing what vehicle i'm looking for would be so much better

To find the spring that matched the characteristics that I wanted, I copied that Moog list into Excel and just sorted it (removed all springs with inner diameters too small for my application and with spring rates < than what I currently have).

To find the vehicle cross reference, I just plugged the "target" part number into http://www.rockauto.com.
Under the "Part Number Search", I would look for the part number w/ "Moog" as the manufacturer.
For example, "CC862".

You could then buy the springs from them (Shipping is super pricey considering how much these things weigh) OR click on the part # in the results of your search to get the vehicle cross reference list.

Regards,
-g

Q: How big is too big for the inner diameter of the springs? They just need to fit under the shock absorber mounts, right? What's a reasonable size delta I can look at?

I will look at aftermarket springs but I'm a little wary b/c of the "cheaty nature" inherent in such springs and and the additional scrutiny such springs may bring. However, considering we're rocking the 140HP V6, I seriously doubt much scrutiny will come upon us.
-g

Myopic Motorsport's #888 Ceci n'est pas une Citron Thunderbird ("This is not a lemon" but a 1995 tbird w/ 93 V8 swap + shopping cart rear wing + engine mounted frito maker)
2017 Sears Pointless Organizer’s Choice
Frito Making Tbird from 2018 Sears Pointless Engine Heat BBQ - http://goo.gl/csaet4

9 Reply by gunn (edited by gunn 2011-03-18 06:27 AM)

  • gunn
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Re: Q: Looking for insights on using other vehicles springs on my 95 Tbird

Speedycop wrote:

I used Vogtland 1.6" drop springs. Worth every penny. If you have room in the residual value budget, do it.

Holy crap! You found $250 for SPRINGS in your budget? Maybe we can find a used deal (I saw someone selling used springs for <$100 in the sccoa archives).

This was after your first rodeo, right?
Besides the cars price, we still have/had to dump money into cars price itself + reliability mods (transmission, coolers, etc). Making sure the car will run for 24 hours has  taken a precedent over keeping the thing making it go around the track closer to the "ideal racing line".

Regards.
-g

Myopic Motorsport's #888 Ceci n'est pas une Citron Thunderbird ("This is not a lemon" but a 1995 tbird w/ 93 V8 swap + shopping cart rear wing + engine mounted frito maker)
2017 Sears Pointless Organizer’s Choice
Frito Making Tbird from 2018 Sears Pointless Engine Heat BBQ - http://goo.gl/csaet4