Suspension
Thread Starter
Safety Car
Joined: Mar 2009
Posts: 3,558
Likes: 4
From: Oakland California
Suspension
How can I tell what suspension I have(regular, F41, Gymkhana)? Is there a specific measurement to any suspension component? The fuel tank was replaced by the previous owner, so the build sheet is no longer there. I would really like to know what I have.
Le Mans Master
Joined: Sep 2002
Posts: 5,236
Likes: 898
From: Myrtle Beach SC
It's helpful to know the model year. Shock numbers, if original can offer a clue and motor. If parts have been replaced, the best evidence may be what the previous poster suggested, leaf spring width and number of leafs.
Le Mans Master
Joined: Oct 2007
Posts: 7,444
Likes: 970
From: Tennessee/Rhode Island
The size of the sway bars varies depending on the year with the 78-80's having the biggest combination of front and rear bars. The earlier years had a smaller front bar but I believe all of the gymkhana suspended cars had a 7/16th inch rear bar. All gymkhana/F-41 cars had a rear bar thus the easiet way to identify one is to just peak through the rear wheel opening to look for a rear bar with an OEM vertical endlink, not a horizontal endlink (like the front bar) which indicates an aftermarket rear bar. Also, as noted above, the F-41 cars have a 7 leaf rear spring versus a 9 leaf base car spring, if they still have a steel rear spring. Finally, my 78 came with a 1 1/8 inch front bar. The F-41 cars did not have a 1 1/4 inch front bar. Hope that this helps!
Le Mans Master
Joined: Mar 2001
Posts: 6,640
Likes: 287
From: Ann Arbor Michigan
Correction, I looked in my "Corvette restoration guide" and it says all 73-74 Big Blocks got the rear sway bar as well as those equiped with FE7 or Z07 suspension. So just having the rear bar is not the tip off for FE7 unless you have a small block. It also says all 73-74 rear bars are 9/16" dia.
Gary
Gary
Le Mans Master
Joined: Oct 2007
Posts: 7,444
Likes: 970
From: Tennessee/Rhode Island
Correction, I looked in my "Corvette restoration guide" and it says all 73-74 Big Blocks got the rear sway bar as well as those equiped with FE7 or Z07 suspension. So just having the rear bar is not the tip off for FE7 unless you have a small block. It also says all 73-74 rear bars are 9/16" dia.
Gary
Gary
Any small block car from mid to late 70's that has an OEM rear bar is a gymkhana suspended car. Also, my 78 I believe did not have a 9/16th rear bar since I remember when I purchased the nylon replacement sway bar mounting bushings and installed them, the rear bar was VERY small, definitely not more than 1/2 inch which is why I referenced the 7/16th rear bar. I currently run an OEM type 3/4 inch rear bar with the stock 1 1/8th inch front bar with poly end link AND mounting bushings. Hope that is clearer.
From Wilcox's website:
42670 1963-1982 Rear Sway Bar Bushings. Polyurethane 7/16 Inch 63-82 $33.99
Last edited by jb78L-82; Dec 6, 2009 at 02:35 PM.
Thread Starter
Safety Car
Joined: Mar 2009
Posts: 3,558
Likes: 4
From: Oakland California
Forgot to add, it's a 74 L82 and all original. I'm going to check the shocks to see if they are original.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
Le Mans Master
Joined: Oct 2007
Posts: 7,444
Likes: 970
From: Tennessee/Rhode Island
Le Mans Master
Joined: Sep 2002
Posts: 5,236
Likes: 898
From: Myrtle Beach SC
Drifting
Joined: Nov 2007
Posts: 1,701
Likes: 272
From: New York
Push on the car, if it moves, you have the stock spring. If the spring is really thick and all that flexs is the sidewall of your tire, you may have a DAytona.
Le Mans Master
Joined: Oct 2007
Posts: 7,444
Likes: 970
From: Tennessee/Rhode Island
Do you know for a fact that the 74 FE-7 did NOT have a rear bar? I am not sure about the earlier 70's SB cars not having a rear sway bar with the sport suspension, thus my question, and my comment above, about only the mid to late 70's C3's having the rear bar. Just trying to confirm although my friend who had a 74 L-82 in college did not have a rear bar either but I do not know if it had the sport suspension.
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Sway bar articles
http://www.northtexasamc.com/pdf/HMM_Anti_Roll_Bars.pdf
ANTI-ROLL BAR RATES
The only job of the anti-roll bar is to handle roll resistance. We can determine the roll rate of an anti-roll bar through the mathematical formula:
R = [(pi)(G)(d^4)] / [(16)(b^2)(L)
where R is the roll rate in pounds per inch, pi is 3.14, G is the modulus of the material; d is the diameter of the bar; b is the length of of the roll bar arm measured from center to center; and L is the length of the anti-roll bar.
As we can see, the diameter of the bar has the greatest effect. Small changes in bar diameter result in large changes in anti-roll bar rate since it varies as the fourth power.
Plug and Chug Bar calculator
http://users.erols.com/dmapes/SWBRCLC.HTM
Formula and Diagram
http://lumenique.com/Cars/mcoupe/mod...tirollbars.htm
http://www.northtexasamc.com/pdf/HMM_Anti_Roll_Bars.pdf
ANTI-ROLL BAR RATES
The only job of the anti-roll bar is to handle roll resistance. We can determine the roll rate of an anti-roll bar through the mathematical formula:
R = [(pi)(G)(d^4)] / [(16)(b^2)(L)
where R is the roll rate in pounds per inch, pi is 3.14, G is the modulus of the material; d is the diameter of the bar; b is the length of of the roll bar arm measured from center to center; and L is the length of the anti-roll bar.
As we can see, the diameter of the bar has the greatest effect. Small changes in bar diameter result in large changes in anti-roll bar rate since it varies as the fourth power.
Plug and Chug Bar calculator
http://users.erols.com/dmapes/SWBRCLC.HTM
Formula and Diagram
http://lumenique.com/Cars/mcoupe/mod...tirollbars.htm
Last edited by flynhi; Dec 7, 2009 at 11:52 PM.
Le Mans Master
Joined: Sep 2002
Posts: 5,236
Likes: 898
From: Myrtle Beach SC
Yeah...just about 100 percent. I've researched and have documented the FE7 suspension system from 74 through 82. The 74 front bar was not as thick as the 75-82 bar...In fact it was the same bar as used for the F41 suspension in early 70's.
