Hi, I am in the process of upgrading the suspension on my 1977 corvette. I am working on the front suspension currently and have replaced the ball joints, calipers, tie rod ends, monroe sensatrac shocks, installed 550lb springs and poly bushings in the a arms. I was going to replace the front stabilizer with the a aftermarket 1 1/8" bar and then I thought perhaps I should just change out the end links and pushings with poly units and keep my existing bar. I do plan on a 360lb composite rear spring and a 3/4" rear stabilizer. Can you guys give me some advice as to what stabilizer bars you would recommend for my set up? The vette is an auto trans and using P245-60-15 front tires and P255-60-15 rear tires.

 

I have a 78 L-82 4 speed that I have owned since 1983 which had the OEM gymkhana suspension. The sport suspension in 78 had an OEM 1 1/8 inch front bar which I still have in the car with poly mounting and end link bushings.I replaced the front sport springs with 550's 1 inch lower than stock and replaced the OEM 7/16 inch rear bar about 10 years ago with a 3/4 inch rear bar with the OEM end links, not the aftermarket rear bars with the endlinks like the front bar. I don't know if you can get a 3/4 inch rear oem type bar anymore. The short answer is that the 1 1/8 inch bar with poly bushings with a rear 3/4 inch OEM TYPE BAR should be ok, not knowing everything about the car. The car will be MUCH more neutral than C3's with just a front sway bar only or even like my car that had the 1 1/8 inch OEM front bar and the 7/16 inch rear bar-all C3's whether base suspended or sport were setup to understeer.
With the setup below, ignoring some of the other pieces that I have changed, when it was pretty much just the springs, the rear composite, and the 1 1/8 inch bar and the 3/4 inch rear OEM type bar became neutral at the limit and at 9-10/10ths driving gradual predictive oversteer. Just beware that you are removing the Generals safety net of understeer with that setup which means you need pretty good driving skills at or near the handling limit.

Here is my setup:

Front:

Custom Blue Printed/rebuilt Gary Ramadei OEM steering box
Speed Direct spreader bar
Poly upper and Lower Control arm bushings
550 springs, 1 inch lower than stock
OEM 1 1/8 inch sway bar with Poly endlink and mounting bushings
255/45/17 ZR ultra High Performance Summer only tires
Bilstein HD shocks

Rear:

360 monospring with poly cushings
Competition adjustable strut rods with heim joints
3/4 OEM type sway bar with poly bushings
Bilstein Sport shocks
255/50/17 ZR tires like in the front

 

Stick with commonly offered combinations of springs and bars unless you well understand/desire the characteristics that going off menu will get you. Overly stiffening rear roll resistance with too much spring and/or bar will necessarily net you and oversteering car, however great it might fell at well below that car's limits. And, bear in mind that there is simply no one-size-fits-all setup.

 

The rear spring/bar combination mentioned by the OP puts an awful lot of roll stiffness in the back, and I'd be worried about strong oversteer. I'd delete the rear bar option initially and see how the car feels at the limit before adding any more rear roll stiffness.

 

I changed everything on the front suspension because it drove like crap.
all over the road at high speeds.Terrible. First time I replaced most of the steering parts with new stock OEM parts and it was just as bad as the old stuff. I built it to drive not to sit in a parking lot on Sunday. After my first trip to the Smokies First thing I did when I got was get rid of the stock front end and replace it with new modern front end. 1) Steeroids rack/pinion. 2) Complete Mono spring front end. 3) Upper control arm cross bar for support. 4) 1-1/4" front sway bar and 3/4" on the rear. Every year for the past 4. I go on the Hot Rod Power Tour. I couldn't do it with the stock front end. Doing all those miles driving like a snake. It drives like a new modern car. Oh ya, The 5 speed Tremic helps a lot too.

 

When upsizing the sway bars, absolutely, positively do the front bar first! If you install a bigger sway bar in the rear first, with the stock bar in the front, you will find that the rear end will break loose suddenly in moderate cornering. Very dangerous!

John

 

Yep, it's definitely better to work from the understeer end of the balance problem towards that you wish to achieve, whatever are your purposes. And, in any event, one should never extrapolate how a car will react at its absolute limits from how great it may feel at anything less, as oversteering cars often handle extreemely well right up until they bite you in the backside (BTDT). Whatever specific setup advice you may get, if not absolutely sure of what you yourself are doing, err towards understeer, especially on the street. Even then, a little thing called "trailing throttle oversteer" (TTO) can still catch you out if unaware.

 

Thank you for all your input. I really appreciate it. What I have decided to do is keep the original 7/8" front sway bar however, I will upgrade the bushings and end links to poly units. I will test drive the car first before doing anything to the rear or further to the front. With the 550lb springs in the front I will have to lower the rear using 8" bolts for better handling and also getting a better stance. I just put on the disks in the front with new bearings today. Should have it out soon and I'll keep you guys posted. Thanks again.