I find I have a rear sway bar for some reason....the PO of my '72 put the bar on presumably when he put a composite spring (dont' know that rating) and it seems way to stiff to me too. Do I have to have the sway bar on because of the spring or can I remove it? BTW...running billstein sports on back and this is a 350 stock automatic. Thanks.

 

If I recall correctly, rear sway bars came on all big blocks or the F-41 option. The sway bar will better your handling by far. I would leave it on !

 

David, you don't need the sway bar. The majority of Corvettes didn't have them.

If you decide to remove it let me know. I have a friend who is looking for one if it is the factory sway bar. I'm sure he would like an opportunity to buy it from you.

cc

 

Blanket statements extolling the virtues of adding rear bar may be well intended, but rear bar is NOT an absolute requirement for optimum handling. Much depends on front bar, spring rates, weight distribution, power output, and the driver's skill, style and purposes. Too much rear bar in relation to these variables and you run the very real risk of eventually learning some expensive and potentially painful lessons about oversteer. (Some define that as when you hit rear-end first.)

I'll admit that rear bar is occasionally a necessary crutch, particularly when compromising between handling and "ride comfort" (whatever that term is doing in the sportscar lexicon), but IMCO awesome as adding rear bar may feel at 7-8/10ths, if you're only presuming how your car will react when approaching 10/10ths (I'm not talking about enthusiast level spirited driving here), be certain to leave plenty of margin for error (yours or another driver's).

Bottom line; any mistake in bar selection is best made in the direction of too little rear or none at all. Don't find out what TTO is by accident. That's my story, and I'm sticking with it.


TSW

 

Sway bars are not necessary but are added to cars to reduce roll and to enhance handling. Just about any car on the road old and new has sway bars to improve the handling. Many cars in the late 70's and eraly 80's had factory rear bars once GM realized that handling was more of a priority for the cars it sold. As stated above most of the BB vettes and the SB cars with the F-41 suspension had rear bars to reduce the inherent understeer of the vettes. In fact, the SB vettes like my 78 with the gymkhana suspension from the factory still understeer predominately even with the factory 7/16 in rear bar, but much less so than with no rear bar. Understeer is much easier to control than oversteer for most average drivers, the reason most cars setup from the factory with this setup. There is absolutley no reason not to have a rear bar if what you are looking for is more neutral handling but be aware, as stated above, that at the limit 9-10/10th driving you will have less margin for error, like any car that is more evenly balanced, than you would if the car understeered. This handling dynamic is NOT bad, but requires more driving skill. With that said, I ran my 78 with the factory 1 1/8 in front bar and rear 7/16th rear bar for 20 years with poly bushings everywhere for enhanced effectiveness with zero issues. About 5 years ago, to neutralize the inherent understeer tendency of the factory setup, I switched to a factory type 3/4 in rear bar, not the aftermarket horizontal rear bar end links, which restrict the movement of the rear IRS suspension. The car is very neutral up to about 10/10ths driving and beyond that point the rear breakaway is very progressive with my total setup. Rear bars can be very helpful but like everything else should be matched to your total suspension. If GM felt that factory rear bars were unnecessary or dangerous, they would NEVER have put them on corvettes both from a cost perspective and safety issue, especially after the corvair fiasco. Just my 2 cents!

 

Up north, I had a 360 VBP plastic spring, and a VBP heavy sway bar on the car, I gave both bars up, as the ride was just too harsh, went Bilsteins for the same reason.....

the rear bar is now a factory bar at 7/16... front is a thin bar at near 3/4 or so...well under a inch anyway....

Car does better than I do....

 

David
Some will randomly add parts w/o sound engineering. Check for a larger than stock front bar. If not, you are probably right for you- better off w/o the rear. You can disconnect it & see.

Note that some of us who have rear bars (I have FE-7 & LIKE IT!) say they are not for everyone & certainly should not be randomly added.

 

Hey fellow Wichita owner. Don't need the rear bar with the Billstien sports, especially since you think it is too stiff.

My car is only used at 10/10s !

 

Thanks fellow Wichitans CC and Jim and the rest of the respondents. But I have to ask one question becaue it's driving me nuts and I like to show my stupidity: What the heck is all this 10/10s, 9-10/10ths stuff. Oh and I am pretty sure this bar is 3/4 in.

 

It's a fractional expression of how near the actual limitations a driver pushes his machine; 10/10ths being where every last ounce of performance potential has been wrung from it. This is not to say that a driver can't approach 11/10ths, where he is operating well and truly in the danger zone beyond the peak of the slip angle/grip curve; just that the reward for doing so won't often be reflected on the stopwatch. It is worth pointing out that what may be 10/10ths for a given driver may only be 8-9/10ths (or even less) for a given car, which would put that car's limits beyond those of said driver; not an uncommon circumstance.

 

I thought he would ask about TTO.

 

I admit I had to look it up but TTO is Trailing Throttle Oversteer. According to Wikipedia, also called Lift-Off Oversteer. Apparently, this is what makes the rear end of the car come around when you lift off the gas in the middle of a corner. I'm no racer, but I always heard it was best to brake straight, then get on the throttle into the turn (I guess for a beginner anyways).

 

David, the factory rear sway bar is 9/16". I should have noticed it was there when we had it up on the lift. My powers of observation are apparently fading. Must be one of those things where you don't expect to see one so you don't.

If I remember correctly, the front sway bar is 3/4" so if you have one that big on the rear, your suspension is being severely limited especially for Wichita streets where you need as much suspension travel as possible.

cc

 

Straight line braking is but one of the classic corner entry techniques; the other (and more difficult to master) being trail-braking, where you turn in as you modulate out of the brake to help point the car. Shy of the car's limits, one may have the option to employ either, but setup with too much rear bar and you're pretty much stuck with the former method (and with how ever much maintenance throttle is required during cornering) once the limits have been reached.

 

Trailing Throttle Oversteer is especailly nasty in a C-3 as the rear suspension isn't very forgiving. I've had the problem, and straight line braking doesn't make a difference. You are beging the turn into the corner and the rear of the car just starts coming around. There isn't much you can do, turn into the slide and hope it corrects or if bad enough apply lots of brake and ride it out. On a race course you loose eough time to screw the run but on an exit ramp hit a curb, rail or worse. A good test for correct rear grip is setting up a 60ft slalom and driving the car through as fast as possible. If the rear is stepping out, or loosing grip first...that is not good. Ideally a race car should be very neutral, a street car is probably best having the front tires loosing grip first. My car is set up so that I can adjust to any surface by adjusting air pressure and sometime a change to the rebound of the rear shocks.

Alignment is also very important. Last year at National Championships the rear let loose on a left hand turn on my last run and ruining my day. I aligned the car this weekend getting ready for next season and found out the right rear tire's thrust angle had moved almost to toe out. Probably the reason for the slide.

 

CC, you did notice the sway bar and made mention of it, that it had been added on. Still had a good finish on it as well. I will get a more accurate measure of it's diameter soon as I can and let you know. I believe that I will be removing it when the weather permits; am anxious to see/feel the difference. Have a good day!

 

In a straight line a sway bar should not effect how stiff the ride is.

The spring, shocks, and tire type are what you need to look at.

 

Any activity that applies upward or downward pressure on one wheel only will affect how the suspension feels with a sway bar.

cc

 

LEAVE THEM ON !!!!

 

JB - I did not that Chevrolet made 2 rear sway bars - I think I have 9/16"... Was the 3/4" indeed factory? Was that maybe F-41? Or later years?