Hello. I'm thinking of upgrading both of my sway bars on a 79 vette. Originals are still installed. I found one at ecklers that caught my eye and wanted to have a second opinion of the sizes for front and rears. Just want the right size for the best handling and control. Please reply on your experience upgrading your sway bars. Much appreciated!

http://www.ecklerscorvette.com/corve...1963-1982.html

 

Two thoughts:
1) The 1 1/8 front bar seems proper, but the 7/8 rear seems oversized.

2) The GM designed rear bar contains a linkage system that prevents binding and possibly getting into the rear tire. The sizes of these bars are either 9/16 (early) or 7/16 (late, including 79) The stock linkage bars seem to be durable, while the aftermarket, which connect to the trailing arm using a bolt/sleeve/cushion arrangement similar to the stock front bar, seem to eat cushions (including poly). This would seem to indicate that there may be a geometry problem with the aftermarket design.

 

As Rotondo states, the front bar at 1 1/8 inch is the factory size bar for Gymkhana/F41 sport suspended C3 SBC like my 78. The factory rear bar on my 78 SB was 7/16 inch..the 9/16 inch rear bar was for the earlier C3's with a Big block. The matched 1 1/8 inch GM front bar with a 7/16/9/16 rear GM bar will still understeer at the limit as the car came from the factory….probably better suited for street duty.

The 7/8 inch rear bar in the kit above has 2 BIG problems:

1. It is way too large for a 1 1/8 inch front bar unless you like an oversteering C3, at or near the limit.

2. A much bigger issue is that most of the aftermarket rear bars like the one above do NOT have the proper GM designed end links that pivot in a vertical plane rather then the horizontal plane like the front bar end links. This arrangement will severely limit the movement of the rear trailing arms in the IRS and are not well suited to the C3 suspension. Regardless of size, I would not use an aftermarket rear bar without the proper GM designed end links. GM purposely did NOT use the same end links on the rear bar as the front. I waited years to change out my factory 7/16 inch rear bar to a bigger one to dial out the understeer from the factory until midAmerica offered the 3/4inch rear bar below-on the car for about 10 years now..The safest bet initially would be a factory sized 1 1/8 inch front bar with the GM rear 7/16 inch sway bar..it is a nice combo with a fairly stock suspended C3 with no drama...

You need a bar like this with at least a front 1 1/8 inch front bar:

http://www.mamotorworks.com/Corvette...le-34-602628-1

My 78 L-82 4 speed came with the gymkhana suspension with 350 lb front springs (?can't recall the rating), 1 1/8 inch front bar. 292 lb steerl rear spring, 7/16 rear sway bar. The car currently has 550 front springs, stock 1 1/8 inch front bar with poly end link and mounting bushings, 360 mono spring, and the GM OEM type 3/4 inch rear bar with poly mounting bushings above…no oversteer…very neutral.

Hope that helps!

 

My 69 had a 3/4 front bar and no rear, very mushy in my opinion. Installed last summer a 5/8 rear bar [aftermarket style] which really firmed up the handling, but noted while driving last summer the front needed help. While the engine was out the front bar was bent and picked up a 7/8 front bar from another CF member. Just got the engine running yesterday, so I'll let you know how it handles in a day or so. T
My 6t8 has the big bars you are looking at, I use that car on the track, the ride is very firm.
So keep in mind when picking out sway bars that they will affect the ride.

 

I am not surprised that you noticed that the ride stiffened up greatly when you switched to a 5/8 inch aftermarket bar with the same end links as the front bar since that rear bar limits the movement of the rear trailing arms, as stated above. When I switched out my factory rear 7/16 rear bar for the GM designed 3/4 inch rear bar, I noticed no change in the ride quality, just a bit less rear lean in turns.

on my Chrysler 300 V6, I put on Eibach V8 sway bars with both bars having factory vertical end links and there was very little change in the ride with the switch and the Eibach bars are MUCH bigger than the V6 factory bars. Same deal with my 2001 Grand Prix… put on GM performance front and rear sways bars…aka Police sway bars…no difference in ride. Springs and shocks effect the ride mostly…IF you use the correct bars.

 

But the difference in price between the OEM and aftermarket bars. Plus also just finding a good OEM setup is difficult. T

 

Take "jb78L-82" advise. A rear sway bar with factory type end links operates smoother and with less binding that sway bars with other type of end links.

 

If you want a factory 9/16 bar, member Redvetracr was recently advertising FS: F-41 factory sway bars. He wanted $195 for the rear bar with linkage hardware. Put that together with a 1 1/8 aftermarket front bar and you're in business for not a great deal more than the Eckler's package.

 

Thank you all, I'll definitely stick with a 1-1/8 front and 9/16 rear.

 

Would the size be relevant if I am running 18x8.5 front and 19x10 wheels.

 

I've got a non-oem rear sway bar I need to install. Been sitting in the garage for a few years now. I spent several hours talking with the guys at Van Steel about my needs. I want to occasionally autocross.

If memory serves me correctly, they mentioned that some of the issues around rear sway bar binding are due to the angle of the bracket/bushing mount to the frame and suggested shimming the mount further away from the frame. So, I had a friend machine somewhere around 1" shims to install between the brackets/bushings and the frame. According to Vans Steel this should reduce/eliminate the binding.

I've yet to actually install the non-oem rear sway bar, so I can't yet personally attest to this method. I do hope to have it installed withing the next month or so.

 

If you are intent on using a non OEM rear sway bar, I would definitely not use poly endlink bushings, use rubber-more compliant, and you might want to consider using an adjustable endlink with a spring between the bar endlinks and the endlink to the frame for even more compliance. The best solutin is a GM type endlink rear sway bar.