Gymkhana

[LanceB]

Where can you look to know whether you have the Gymkhana suspension option?

 

[TJay]

What year Corvette LanceB,

Gymklana first appeared on 1974 Vettes. Difference is ..
0.9375 (23.8 mm) dia front stabilizer bar
Heavier front bushings
550 lb rated front spring
304 lb rated rear spring
Option # RPO FE7G81 (1974)

Just noticed you have a 1981..
Option # RPO FE7

 

[spikebot 81]

Look at the rear spring. It should be 2 1/2 wide with 9 leafs.

 

[Vette79]

OR you could look for the obvious rear sway bar!!!

 

[vette427]

I thought the FE-7 had a 7 leaf rear spring?

 

[GTR1999]

my 75 has Fe-7
it has even spaced frotn coils, look like aftermarket but they're not
Bigger front bar
rear bar
7 leaf steel spring
had different shocks I believe

 

[Peer81]

What I know is that a 81 normally has a composite leafspring but manual gearboxes and Gymkhana had a steel leaf spring. As said the easiest to see is if you have an original rear swaybar.

Groeten Peter

 

[spikebot 81]

I thought the FE-7 had a 7 leaf rear spring?

Thats what I thought too. This am, before I posted, I went out to look and counted 9. Tank sticker say FE7 for sure and the rear sway bar is in place and really small diameter. Front bar is at least 1 inch or bigger. Now I'm confused. I guess someone could have changed the rear spring. This car rides like a tank

 

[GerryLP]

I thought the FE-7 had a 7 leaf rear spring?

Not in 1981 Vettes....:ugh

 

[GerryLP]

Thats what I thought too. This am, before I posted, I went out to look and counted 9. Tank sticker say FE7 for sure and the rear sway bar is in place and really small diameter. Front bar is at least 1 inch or bigger. Now I'm confused. I guess someone could have changed the rear spring. This car rides like a tank

The funny thing is that when I called Chevrolet's restoration number and asked them about it (approximately 4 years ago), they told me that technically, the little one at the top is not counted as a leaf per se. Since it does not have an effect on the working spring ratio. But who's counting anyways...:L... And usually, the FE7 spring is a bit narrower, but the L81's had 2.5" springs.

I lost my original special shocks during a move years ago. I would love to get myself another set.

 

[spikebot 81]

Thanks Gerry, It was real early this morning looking under the car. I'm suprised I did'nt see two springs side by side

 

[GerryLP]

Thats what I thought too. This am, before I posted, I went out to look and counted 9. Tank sticker say FE7 for sure and the rear sway bar is in place and really small diameter. Front bar is at least 1 inch or bigger. Now I'm confused. I guess someone could have changed the rear spring. This car rides like a tank

Having the rear anti-sway is it. But to make sure it is not after-market, measure the diameter. It should be approximately 0.440". The spring rate is 121 lbs/inch at the wheel, with an overall rate of 172 lbs/inch.

 

[LanceB]

Hmmm, dont see a rear sway bar on either the 77 (brothers) or my 81. Just see the struts and springs. Is it worth adding one handling wise? So far both suspensions are all stock as far as I know, at least neither has been upgraded or changed in 10 years. I see the ADDCO ones in Corvette Central.

 

[GerryLP]

Hmmm, dont see a rear sway bar on either the 77 (brothers) or my 81. Just see the struts and springs. Is it worth adding one handling wise? So far both suspensions are all stock as far as I know, at least neither has been upgraded or changed in 10 years. I see the ADDCO ones in Corvette Central.

Lance,

If you want handling at is best, there are a good handful of suspension upgrade packages out there that will improve the handling well above Gymkhana. As far a simplicity or ease of installation, you could add the anti-sway bar only.

I have driven my Vette since 1985, so it is hard for me to give you a fair assessment of the handling. I does feel as in rails, and it hardly leans, but I would have to drive a non-HD suspension to have a chance to sense a difference (if that would be possible).

The HD's best feature performance I have noticed is in the few occasions I have taken Gail above 120 miles per hour. She's steady, and she does not wave nor bounces from changes in the road.:ugh But I hardly ever take her to that speed (the last time was in the mountain roads of Colorado Springs).

GerryLP:cool

 

[JohnZ]

Is it worth adding one handling wise? I see the ADDCO ones in Corvette Central.

If you add a rear bar without upgrading the stiffness of the existing front bar, you'll increase rear roll stiffness and dramatically increase oversteer, especially in transient maneuvers near the limit. Suspension roll couple distribution is a system - most attempts at re-engineering the suspension one end at a time out of a catalog are very disappointing. :eyerole

 

[LanceB]

JohnZ - I see your point! Leave well enough alone?

 

[GerryLP]

If you add a rear bar without upgrading the stiffness of the existing front bar, you'll increase rear roll stiffness and dramatically increase oversteer, especially in transient maneuvers near the limit. Suspension roll couple distribution is a system - most attempts at re-engineering the suspension one end at a time out of a catalog are very disappointing. :eyerole

JohnZ,

I am not sure if the front stabilizing bar on the HD suspension Vettes and the non-HD Suspension Vettes are different. But the information I posted was from Chevrolet, and they didn't seem to mention any other stabilizing bar for the front. And the rear spring rates appear to be applicable to the mono-leaf and multi-leaf. The coil springs are different, if I am not mistaken, for the stance height is slightly different on the HD-suspension Vettes.

I believe that the F-51 shocks, for example, were not available with the FE7. The shocks for the FE7 (or perhaps FE7 with ZN1) were called "special". So apparently, to have the ZN1 it had to be automatic transmission, HD Radiator, FE7, and special shocks. But I wonder if there are any FE7's with no ZN1?

It would definitely make for a fun road test to somehow make the comparison, but I feel that the over/under steer would probably not manifest itself. Whatever under/over steering is detectable is probably inherent of the design for the 1981 Vette. They were pretty good Vettes, but not perfect...heck that applies to today's ZR1 , albeit, today's ZR1 is a hell of a lot closer to perfection than the 1981 Vetteotfl

 

[73shark]

I put a 1.125" GM bar on the front and a 7/16" GM bar on the rear for autocrossing and it made the car more neutral w/ just a hint of oversteer.

 

[Vette79]

I put a 1.125" GM bar on the front and a 7/16" GM bar on the rear for autocrossing and it made the car more neutral w/ just a hint of oversteer.

Yep, did the same thing. Like John said, if you install a rear sway bar you should increase the size of the front sway bar. My front stock sway bar was 1'' in diameter.

 

[Deadlego]

How thick is the rear bar? I seen a little one my car. It has the thickness of a pen. I dont know if have this option or not. Need to look for tank sheet.