I would say yes that is a very good way to support the rear body roll and would be far superior to a factory bar. This bar might be better for a protouring or auto cross racing but again it will help keep the weight centered.

 

Without a doubt the mounting shown is better. Actually the bar mounts on the rear end tubes and the links extend to the chassis. I think the bar also has two or three hole so you can adjust the stiffness or action. I made a pair of spring loaded links for my Willys to soften the massive bar I have to use on the narrowed rear end. These work great.

 

Idk, I didn't have a rear sway bar until I upgraded to a Hotchkis front and rear. In my case the handling was WAY better. I mounted the rear sway bar upside down after checking that it would clear the rear end casing. I didn't like how low the bar was hanging off the bottom of the car, so I flipped it. It's now flush and works the same.

 

I have the Hellwig Pro Touring rear.
Had to drill one hole on frame each side. Had to bend the brake lines that run along axle tubes to get u bolts in. I used some rubber hose to then protect the brake line too.

I'm on the softest setting and it's pretty awesome. Along with the Hellwig 1 5/16 front bar.

 

In theory, the sway bar, essentially a torsion bar, doesn't care where it's mounted. The stiffness is determined by the bar diameter, the bar material's modulus and the arm length. The chassis-mounted bars usually have a considerably shorter arm length, giving them a higher roll resistance since the arm length is shorter than a factory bar, which uses part of the control arm as its arm length.
Just know that if you go too large in a rear bar without proportionally increasing the front, you'll have a vehicle that wants to swap ends quickly in hard cornering.
I used to do that years ago, when I autocrossed my 70's Corvette. The setup that worked well to get the rear end hung out on a tight autocross course gave me some hairy moments on higher speed corners out on the road.

Bill

 

Let me throw this out there. I'm restoring my '74 in a very 80's fashion - factory control and A arm suspension, heavier springs, and adding a factory rear sway bar. A good source told me to keep the smaller sized front sway bar because that's what the factory did. He beefed the front bar when he added a rear bar in the past, and often lost control of the car in tight turns, in traffic. Not cool! He researched and found that the factory used the smaller up front when a rear was installed to avoid the car getting too tight, causing exactly what happened to him. Any input is welcome. Thanks in advance!

 

Let me throw this out there. I'm restoring my '74 in a very 80's fashion - factory control and A arm suspension, heavier springs, and adding a factory rear sway bar. A good source told me to keep the smaller sized front sway bar because that's what the factory did. He beefed the front bar when he added a rear bar in the past, and often lost control of the car in tight turns, in traffic. Not cool! He researched and found that the factory used the smaller up front when a rear was installed to avoid the car getting too tight, causing exactly what happened to him. Any input is welcome. Thanks in advance!

 

I have to respectfully disagree. Without getting too technical, adding additional roll control (stiffer springs or stabilizer bar) to a vehicle will tend to make the end of the vehicle break traction that has the greater roll control. Normal vehicles are biased to understeer (front end looses grip first), since it's a safer characteristic for the average driver. Performance vehicles attempt to increase overall cornering ability by adding roll control at the rear, which could cause the rear end to lose grip first (oversteer). I don't have any info in front of me for the earlier models, but for '78-'87 G-body passenger cars, the standard front bar was approximately 1 inch in diameter. When a sport suspension package was ordered, the front bar was increased to 1 1/4 inch to accommodate the addition of a rear sway bar.
I have both front sizes in stock for my '87. When I first installed the rear bar with the stock 1 inch front bar, it was a ball to drive, since I could easily break the rear loose in a tight corner. However, changing over to the larger front bar, while not allowing me to toss the rear end around as easy, definitely increased the overall cornering ability.

I know we have a member here from UMI Performance, who knows far more about suspension than I. Hopefully, he'll chime in and either agree or tell me I'm full of hot air. I studied passenger car suspension theory and application, as I autocrossed regularly for quite a few years, but in the 80's I got involved with a dirt-track Sprint Car, which is in a completely different universe as far as suspension setup.

Bill

 

You got it right, Bill. My experience says a stock front bar WITHOUT a rear bar is fine. Adding a rear bar calls for increasing da front bar size.

 

Great input. Wonder why he had control issues then. He said that no matter what he did, when he began to spin it was unrecoverable. We're talking about a '70 Monte, by the way. Since the smaller front bar is free and here, I'll start with that. Thank you again for the input - what you said makes perfect sense. And it's what you would expect, which is why what he said had me a bit stumped.

 

I'm doing a step by step handling improvement on my 77 SS. Most consider these as land yachts. However the SS version already has much improved suspension over the classic version. Next they already come with taller spindles and the best A body geometry. Not perfect but pretty good. This come from the book "How to make your muscle car handle".

So first step was to push the stock set up. Mine had Goodyear Eagle St tires 225x70x15 of questionable age. They were old for sure. The roundabout test nearly put me in the curb as the front end pushed badly and quite a bit of body roll. The sashay test on the road was like old time rock and roll. Brakes was just humorous. And the acceleration test was just spin tires on pavement without even stepping on it hard. So I had my work cut out.

The first thing I did was replace the tires and wheels with 275 60 15 BF Goodrich TA on 15 X 8" rims on the rear and 255 60 15 on 15 X 8" fronts. The transformation is spectacular. It's like a new car. Every test was hugely improved. Yes I could have gone to more performance tire but this is not a racer.

Next was the UMI 1 1/4 front sway bar. Here is another spectacular improvement. Again every thing is just made better. There is no front end dance anymore and the big car has a light and nimble feel. The tires no longer roll under on hard corners.

What's need now? Rear sway bar. As I noted earlier the axel or chassis mounted one is best and that's what I'll get. I don't like the stock style. Additionally I think I may explore a Panhard bar even though the rear suspension is triangulated. The bushings make it a little loose in the rear. More thought needed.

 

I'd be hesitant to add a panhard bar, as introducing the lateral control of the panhard bar could lead to a conflict with the geometry of the existing four-link, causing a bind.
Rather than adding that, replace your existing bushings with poly, or even considering replacing the control arms with stiffer boxed or tubular ones.

Bill

 

Already have boxed lower and upper control arms. Actually they are tubing rather than welded. They have harder bushings too.

I'll see what happens after the rear sway bar install.

 

Wise choice.
All a panhard bar does is maintain lateral location of the rearend with respect to the chassis. As you've likely gathered from other posters, adding a rear sway bar makes a huge difference in roll control, complimenting your big front bar.

Bill

 

Spohn Del Sphere rear control arms, BMR 2" lowering springs and Jounce bumpers instead of a rear bar...

 

This is a fourth gen car. Many parts used on other A body cars don't fit. Most co's don't make much for these cars. In some cases it's not needed anyway excep for racing. This is not a racer.

Springs and bushings are " maybe" down the road.

The rear anti roll bar is next big change. Only two co. That I know of Make axel mounted bars for this car so choices are very limited. These have at least two adjustment holes so it will be interesting to try them in a controlled environment.

Thanks for the replys.
Byron

 

Well, I got the rear anti roll bar installed today. Detroit Speed. It's nice. It was a bit tedious but when you have to work outside in 90 deg weather anything is tedious. Anyway it's in and it fit. It doesn't hang down below the center section.

Driving it really compliments the big tires and front bar. It's not as noticeable as the tires or front bar were but you definitely know it's there when you push a corner. I installed on the inner holes or stiffest rating. Going down the road I don't feel any difference but on wavy roads or going over a bump with one wheel it lifts the whole end of the car some. Not a problem however. The car feels very stable now. There is no wishy washy rocking and rolling like before.

As I noted earlier I think a Panhard bar would help. I'm going to look into one maybe with one urathane or poly bushing on an end to cut road noise. I forgot to check clearances today. I have an old diagonal link around somewhere for parts.

This is going to be about it for suspension for now. I'm going to call Hawk about front brake pads. I'm really abusing the brakes in our messed up traffic on the freeway.

I also discovered the rear air shocks are not OEM replacements I thought they were. They a Gabriel Hy Jackers. Yuk. No wonder the rear end is chattery on washboard surfaces.

Byron

 

Is anyone running a chassis mounted rear sway bar? Is there really that much difference in handling compared to a factory style bar? I understand the differences between the 2 (different mounting points etc). Just wondering if it justifies being almost 3 times the price of a factory style bar.

chassis mounted bar im looking at,
http://umiperformance.com/catalog/index.php?main_page=product_info&cPath=2_34&products_id=746

Link didn’t work but chassis mounted link style is definitely better. Mine has 2 stiffness adjustments with the stiffer one round abouts are fun. I have slightly stiffer front that totally flattens out corners big tires and wheel help. Currently having quarter panels installed to finish off rust then new black paint and painted white SS markings then it’s for sale. Not that I don’t like the car I’m not supposed to drive and you don’t want me on the road. It has a lift up tonneau cover. This could use new vinyl . My son and grand son have my industrial sewing machine so I cant replace it myself. The co. That made it is long gone but it would not be hard for boat repair shop to handle. I may just have them take it to one lots in Minn. so it’s as complete as I can make it.