A little torsion bar experience and advice needed.

[Jeremiah]

Perhaps 2" drop spindles are the answer?

 

[Kern Dog]

Good thought, but you actually have it backwards. The more you raise the nose of the car with the torsion bar adjuster, the stiffer the spring support effect. Lower the bars and they don't do the job as well. That's why with a slight downward rake I like my 1.00" bars better than my old .088" 's.

The other thing to watch out for is the larger diameter the torsion bar, the more resulting understeer. More and more positive caster can also increase understeer, as can adding a front sway bar or increasing front sway bar size and your steering box firmness (Stage I is lightest, then Stage II like I have, then Stage III steering box). It depends on your driving style.

Torsion bar manufacturers also caution against using larger than the 1.00" bars in conjunction with 2" drop spindles due to fit issues.

Kern-dog and Furry Frog, since you're both running the big bars, are my facts above correct from what you've seen and also does your real world experience with your car setup support this?

I look at the whole car as a system rather than just focusing on one end. In short, you are right and I am glad to see that someone else gets the relationship of roll stiffness with understeer, oversteer.

Another way to look at it: The stiffer the front or the rear, the more likely that it will be the end to lose grip first. A front sway bar is a bit of a strange thing because while it does help the car remain flatter in corners, it can also also increase the point at which the front end starts to slip. A moderate torsion bar, a moderate front sway bar and a moderate leaf spring rate will be a good handling car. As the enthusiast wants better handling, higher cornering ability, each component needs to step up. Larger torsion bars, larger front sway bar and a small rear sway bar. In keeping with this, I went with 1.15 torsion bars, a 1.25 front sway bar (Both MUCH larger than the stock .88 T bars and .90 sway bar), Mopar Performance 440/Hemi leaf springs and a 3/4" rear sway bar. I didn't have this combination in place from the start, I tried different combinations to get the car to feel just right for how I drive.
Street setups can differ from a road course arrangement though. A car that handles neutrally in corners/transitions under 50 mph can get loose at 70, 80 mph and up. Oversteer at speed is a very dangerous thing as it leads to hanging the tail out "drifter style". Obviously this can result in a crash or a spinout. A slight understeer tendency is safer for almost all situations which is why the automakers designed the cars to perform and react this way. Understeer in a car causes the driver to instinctively slow down until the car feels controllable again.
Again, a moderate torsion bar, front sway bar and leaf spring will handle well, understeer at the limit but be safer and more predictable.

 

[furryfrog]

Well, Regarding using torsion bars to drop the front end, a little would be ok, but the further you go down, the closer you are to your bump stops and limit your suspension travel. It all depends what one plans to use their car for. I think drop spindles would be the way to go. In my case at the moment my car is cranked right up in the front, lot's of bumpy roads here and potholes everywhere, I need the suspension travel. Drop spindles may be on my list at one point.

I have not pushed my car that hard in the corners yet, just under 500 miles since I put it on the road. I am not experienced/ knowlegable on the how to's of suspension/handling, I just did not wan't a twin tubo 440 in the crappy handling, jalopy of a car that it was before. I Phoned up Firm Feel and went with thier recomendation's, Dick asked if I planned to do any autocross, I said yes.

Just to list out what I have going on underneath, 1.12 torsion Bars, stage 3 power steering box, 1 1/8 front sway bar, 7/8 rear sway bar, and HD street/track leaf springs, tubular upper control arms, aluminum body to k frame mounts,bilstiens, and greasable pivot pins. Perhaps after getting used to the car I will have more imput, Others here seem to have much more experience with this. I will say these upgrades have completley transformed the car! I would advise anyone who actually plans to drive their car on the street to upgrade the suspension/handling first, even before doing engine upgrades. I still have 15 inch rims on the car, I now think that I will stick with the 15's, so I can get more traction when I stomp on it.

 

[super-bee_ski]

All good info.
All good!

 

[Cranky]

I have 1.12 torsion bars in my 74 clonerunner, It is the size Dick recomended along with the other items in a stage 3 package from firm feel. My big block car handles better than I expected it would, what a difference! I am happy with the 1.12, for me I would not want to go smaller than that.

After reading as much as I can on this subject throughout the forum, I am wondering how much effect raising or lowering the ride stance has on the torsion bar support/ performance? I like the idea of dropping the nose an inch or so to get a better stance and thinking through the mechanics of how the torsion bars operate. It seems to me if you drop the nose an inch from normal ride heigth, the bars will have more tension on them and make the ride stiffer. Does this sound right to everyone?
So if I put .960" bars in the car with a 383/727 and drop the nose to get the stance I want, the ride will be a little stiffer. Let me know if I have this wrong because it is all speculation at this point and I will be dropping a 440 in there later. Thanks for the help!

As you see, there are many different opinions on what makes a car handle. There are also more than one way to make your car do what you want it to do. There's many who like their cars to 'act' differently. I guess I'm trying to say that what works well for one, may not work all that well for another. For example, I like just a touch of over steer under throttle in my cars but just a touch. With under steer, you usually have to let off (like mentioned earlier) to make the car continue through the turn without running off the road or biting the wall. I hate that. I also like my street cars to ride decently going straight down the road so I usually go with a little bit smaller torsion bar, a shock that's a bit softer but go up in size with the sway bars. One of the first things I used to do when I got a new car was to replace the factory shocks as they were pretty much just a 2 dollar shock. Now a days, they seem to be much better but so are the tires too and the suspension pieces. Tire inflation makes a difference too. What it amounts to be is it's a huge experiment to get exactly what you want. Experiment with tire pressures only and see what a difference that makes!

Lowering a car lowers it's center of gravity and will generally help it handle better. Ever notice how a vehicle with a high CG leans more in a turn? Not sure about placing more tension on a bar or not by lowering or raising but you will have the same amount of weight on them unless you lower or raise the rear end. Place a set of scales under the front end and then raise the rear 2" and see what the scales read. You might be surprised.

Several years back, a buddy built a 440 Cuda and went with big bars, both torsion and sway and shocks from hell lol. It handled pretty dang good but it rode like a lumber wagon. He loved it....I hated it 20 years ago. He never would try a softer shock but I bet it would have rode better and still handled.....

 

[Jackpot50]

62 Polara went from .780" 361 Cu. In. bar to 1" 440 Cu. In. best move ever made handles great, not too stiff.

 

[Mocajava]

Wow! I am always impressed with the amount of knowledge this forum can provide as a resource. I do appreciate everyones input which puts the decision back in my lap. I hate doing anything twice but it sounds like I may have to revise my plan to take this in steps as to the modifications I make while the car sits in limbo prior to the final build. I WILL rebuild the front end and step up size on torsion bar, but may wait to update to disc brakes and new, dropped spindles until after I have her on road for a little bit. My thoughts are to change spindles with disc as a package to make sure they work with each other, whether it be dropped spindles or standard. I only had a trip or two around the block before I started stripping the car so I have no feel for how it handled. Yes, a firm feel power steering unit is still in the works as an upgrade but that may be the end of mods until I get some road time to be confident of my next move. Thanks again, I have a lot to digest from all of the input.

 

[Cranky]

62 Polara went from .780" 361 Cu. In. bar to 1" 440 Cu. In. best move ever made handles great, not too stiff.

Any other changes? What shocks, wheels and tires are you running?

Wow! I am always impressed with the amount of knowledge this forum can provide as a resource. I do appreciate everyones input which puts the decision back in my lap. I hate doing anything twice but it sounds like I may have to revise my plan to take this in steps as to the modifications I make while the car sits in limbo prior to the final build. I WILL rebuild the front end and step up size on torsion bar, but may wait to update to disc brakes and new, dropped spindles until after I have her on road for a little bit. My thoughts are to change spindles with disc as a package to make sure they work with each other, whether it be dropped spindles or standard. I only had a trip or two around the block before I started stripping the car so I have no feel for how it handled. Yes, a firm feel power steering unit is still in the works as an upgrade but that may be the end of mods until I get some road time to be confident of my next move. Thanks again, I have a lot to digest from all of the input.

One thing to keep in mind is that nose heavy cars can be harder to to make handle. It can be done but it's simpler if the car is as close to 50/50 weight bias front to back as possible. I always gets rid of the undercoating on my junk and use as much aluminum and light weight components as I can....especially on the front end.

 

[Kern Dog]

I had a 7/8" rear sway bar but it allowed the car to oversteer way too easily. For autocross, that is great though. Tight turns can be made tighter when the rear end comes around a bit. For anything faster than autocross, oversteer can be tricky when it comes on real fast. Sudden swerves in heavy traffic may make you want a smaller rear bar! Try it and see. With mine, I tried going with softer sway bar bushings at first, thinking the increased deflection of rubber bushings might lessen the sway bar effectiveness. It didn't help much. The rear bar I had was an Addco and was axle mounted. The Firm Feel bars are frame mounted, a better design. My 3/4" rear bar I have now came from a 1983 Imperial. I had to make end links for it but I enjoy minor fabrication stuff.

 

[Mocajava]

Well gents, a new issue popped up last night while trying to remove the entire rear end and springs from my Coronet. I have her on jack stands with another floor jack under the rear end to remove tension from the springs. While removing the lower nut on the passenger side shock, the threaded part of the boss sheared off. This left the shock still in place on the over sized boss with the rubber bushing. Easy enough to finish getting it off, but a new replacement issue to deal with. In looking at the piece, it appears this is a stud that is pressed or welded into the spring hanger. Has anyone had this happen and how did you replace/ fix it. Are there replacement studs available and if so, where? Didn't have that much torque on it to get it removed and the threads seemed pretty clean before I shot them with penetrant. Looking at the cross section of the material at the shear, this was not a previous crack....it happened as I was backing it out. Anyway, could use some previous experience if anyone has any. Thanks

- - - Updated - - -

Thanks for the pictures and description of your sway bar fabrication Kern Dog, I like how that looks! Hadn't even thought of the sway bar aspect yet, still in the tear down mode. With the weight of these "boats" we drive I remember how my 68 SuperBee would sway in the breeze while cornering (I'm sure the extended shackles didn't help!). I will need to plan for some type of assist and you have given some very good advice and real experience for me to think about. Another post for my files as a referrence for later work. Thanks..

 

[Kern Dog]

That picture is actually of the Addco bar, the 7/8" bar that I removed.
Regarding the lower mount for the shock, maybe you just need a new or good used leaf spring/shock plate? I might have a spare or two. Which side? Left/driver or Right/passenger?


The pictures below are of the 3/4" rear bar. It seems odd that I had such a dramatic difference from just 1/8" of diameter but it is true.

I had to fab up the end links. They originally came on a Ford truck! In original form, they looked like "dog-bone" loops at each end, similar to the end mounts on our rear shocks. See the picture where it mounts to the welded bracket on the axle. At the top, I welded a threaded stud to use traditional urethane bushings. It isn't very pretty but it works well.

 

[Mocajava]

Kern Dog
It is the right/passenger side and how much do you want for it if you have one?We can take this off line to discuss and work through PM's.
When you set up the prefabbed linkage, did you set placement of the bracket mounted on axle by running it up and down to full extent so you knew you had enough swing? I can see that what you have looks great and I am sure functions well. My concern would be that the sway bar doesn't prohibit movement for springs/axle under "hard" conditions. It is probably a trial and error and is different for each car with how everything is set up. I did something similar with the 9" plus the trailing arm suspension I set up in my 55 Belair. I am prepping the axle in the Coronet for sandblasting now and will save this and may even get brackets like this fabbed up for a later install when I get the sway bar. Thank you sir!

 

[Kern Dog]

I had the car on my lift to get the rear bar installed. I set tall jackstands under the axle and front suspension then lowered the arms of the lift. This allowed the car to be supported by the suspension. I positioned the bar so that the "levers" were horizontal at what equated to the static ride height. This allowed the levers of the bar to have a range of travel almost as far as the leaf springs and shocks allow. What helps is longer levers/arms! A sway bar with short lever arms would surely restrict up and down movement.
I got your PM and responded.