I upgraded my 79 L-82 to the F-41 style suspension few years back new heavy front and steel rear springs and a 3/4 rear bar and new poly bushings. The rear bar is the adjustable type with a spring between the bushings. The car is now too tight I mean it's real squirrley at above 80 MPH. If I just barely move the wheel it it will change lanes. It's not allignment. It runs straight and true. I wanted more response but this is a little drastic. Is there any way to adjust the rear bar. I put a little tension on the springs but don't really Know how to guage the effect on response. I can't find anything out there on adjusting it.

I was also wondering about tire pressure. I'm running 235/60/15 goodyear eagles at 32 PSI. The sticker pressures are different but they are with 70 tires.

 

Hot Stuff- I upgraded the suspension on my 68 convert like you did, but have not started to dial in the handling. However- I have five sets of coil-over springs and two sets of anti-sway bars for my 93 RX-7 and spent months fine tuning the balance. Having the rear sway bar too stiff almost always increases oversteer and if really stiff will make the car loose and squirrely like you describe. Start from scratch by completely taking rear sway bar out of the picture (disconnect one side completely). Check handling and add the smallest increments of resistance you can get in the back and go from there. Tire pressure also is a factor, so you have dozens of combinations to try out. Welcome to the changing world of suspension tuning! RA

 

Who made your aftermarket suspension? The manufacturer should be able to tell you how to adjust the rear bar.

 

I think it was Mid American or some similar name. It's been a few years like maybe 6 or 7. I haven't had the car on the road for 3 or 4 years. I worked on it a lot when I bought it but got busy and left it sit in the garage for a long time. I pulled the cover off of it a few days ago and thought this thing is really beautiful, an American icon, built right here. In the city and neighborhood where I grew up. I'm going to get it up and running, now that I've got more time. so here I am a 68 year old Corvette owner/operator.

 

I take it you are in St. Louis. There are a group of us here that are C-3 guys and I am sure someone would be happy to help.

 

This really sounds like an alignment issue, or maybe bad bushings.

 

Too much + Caster will also cause this. Take it to shop and see what you have. Take 1 deg out and drive it. If it is a caster issue you will see it right away. When you modify suspension the factory settings are not good.It is a starting point.Just something to check.Not saying this is it.

Chuck

 

Disconnect one side of the rear bar and try it again. Also the car MUST be setting on a flat surface at ride hgt when setting the bar, if the bar is preloaded to one side they act weird. Same for the front.

 

Too much toe OUT will make it feel darty at highway speeds as well.

The sway bar doesn't come into play unless to are close to or at limit handling, which you are not when going straight down the highway.

 

I guess I'd like to see this "adjustable type" rear bar "with springs between the bushings"

 

Hot Stuff- If you are serious about tuning your suspension, find someone who does amateur racing (and is successful) and see if they will help you. Half of the replies here, while attempting to be helpful, are blind-leading-the blind. I spent almost a year following the crew of Dale Jr. when I lived in NC to pick up any tidbit of info they would share. NASCAR, I know, but these guys spend half of their time on suspension tuning and are experts with high dollar budgets. Handling on the RX-7 I was trying to tune improved much, due to their help and despite their ribbing about my cute little Japanese car. RA

 

I thank everyone for the information. I dug through my receipts and found that I was a little off on the dates. I bought all of the suspension parts and a new differential housing from Vette Brakes and Products in 1995. All the receipt gives me is a 7 leaf rear spring, 550 lb front springs and a 5/8 rear bar kit plus all of the bushings. I found another later 1995 receipt from Elco Chevy for a 4 wheel alignment. I remember this one it's for $275 I was shocked and shocked even more when I got under the car a few months later and discovered that Mr. bad wrench had used a pipe wrench to turn the adjusters which had chewed them up badly. Naturally they denied doing it when I went out there and asked them to replace all of the parts their guy had damaged. One thing for sure I won't be going there ever again and I sure won't recommend them to anyone.

Back to this issue. I went out and had a good look at the tires with a depth guage and from the tire wear I don't think I've got any angle or toe issues. I can't find any info on adjusting the rear bar but I seem to remember something about driving it in a circle to see if it was tracking correctly and adjusting it from there. If anyone knows anything about this I'd appreciate hearing from you. Otherwise I'm going to try unloading the bar and adjusting it from there and see how it goes for a start

 

Yes, I grew up in Walnut Park about a mile from the Chevy Plant. One of my neighbors worked on the Vette line and had a 65. I toured it a couple of times with the Northside YMCA. Pretty cool it was hand built then. I also toured the Bowling Green plant when we went up there on Labor day 1995 for the 1'st anniversary of the museum. A lot different. I'll get in touch when I warms up enough to work on it and I get it going again

 

nowhere do you mention the size of your front bar, if you didn`t upsize the front bar take off the rear bar

 

It's a factory 7/8 front bar for the L82. All I did with it was change all of the bushings to Poly.

 

I thought the F-41 package used a 1-1/8 front bar...

 

I'm not an expert. I ordered what the Vette Brakes and Products guy told me I needed to get it to the f-41 gymkhana...whatever package that was offered as an option in the 79

 

I have a front bar and rear spring off an F-41 equipped 79 and the bar is 1-1/8, bar & rear spring both available, if you or anyone else is interested send a PM

PS:the factory rear bar was 7/16