They are, Donnys got one on his 32 roadster, along with a few other tricks. This car wins the GG autocross. Maybe he'll chime in here
Then my next question would be... just how does a straight axle resist or control the roll of the body and frame as it leans from side to side "over" the suspension in a curve? There doesn't seem to be any significant resistance to the roll in a suspension that just has springs and shocks. Gary
The sad fact is most drivers, including those with Hot Rods, don't know a good handling/riding car from the mediocre stuff most of us drive. For typical daily commute most vehicles have a "good enough" suspension. When a driver intentionally pushes the vehicle to it's limits...or an emergency evasive manuver is needed.......is when the difference shows up. Hot Rodders in particular are quite often more concerned with "Style" than function. the best builders have found ways to combine both, but, IMO, they are a minority. Ray
I have the anti-roll bars on the front of my F-100. With them and good shocks there is a major difference. A BroncoII sway bar front and rear is almost a perfect fit and the right stiffness.
Ford used them on their passenger cars since at least 1940. When rodders split the wishbones or use radius rods, the axle becomes the sway [or stabilizer] bar...not the best setup but if the mounts are heavy enough and the car is light enough, it works. Not recommended while using a tube axle because it won't flex like a beam axle.
What Hnstray said - most rodders are more interested in packaging in all the stuff they need for a basic straight axle front end without looking for another thing to have to squeeze in. The rock and roll that occurs when shackles move when cornering has an impact on cross-steering systems - that's probably more of an issue than a roll bar. Packaging a panhard rod in there just adds to the congestion. Both are worthwhile, but rarely used. Just hope you don't need to avoid something that you weren't expecting - you know, like a moose or Bambi or some numbskull in an SUV who didn't see you.
They are more effective on the rear, the torque being applied on hard acceleration tries to lift the left front and lower the right rear. High horsepower/torque cars always use the rear mount.
I used a Chassis Engineering front sway bar on the front end of my '27 RPU, On the rear a modified Schroeder Racing Products rear sprint car style sway. The car handles great, & on four ply tires to boot! Just 'cause your cars traditional doesn't mean it has to handle poorly.
I'm using a 47 olds truck arm in the rear of my 33 p/u . I kept the factory rear bar and just found one for the front. I haven't mounted the front yet. Any input as to where to mount it? I have room to mount on top or bottom of the frame, and can attach at the spring to bone mount. ( suicide 36 ford axle / split bones) or can go to the axle. My gut feeling is the mounting points aren't all that critical.
Adding a front anti-sway bar (or a larger bar) to the front of your vehicle will induce more understeer. Most of us are used to understeer as most production cars understeer. When you push harder into a turn, you have to turn the wheel a little further and eventually, the front starts sliding. Adding a rear bar induces oversteer - that handling trait that gave Corvairs a bad name. If you have a front bar and it plows too easily, a rear bar can help that. With no front bar, that rear bar may make it very prone to being 'tail happy'. Both can improve your handling, when used in the proper circumstances. As was mentioned earlier, you won't feel the difference until you are at the edge of handling. Be careful.
Actually, I think if you will do a little more research, you will find the opposite is true.......stiffer rear induces understeer in the front.....stiffer front induces oversteer in the rear... Ray
Here is a picture of my step dad's car with front and rear anti Roll bars,best driving car i've been in, he spent LOTS of time dialing the shocks, springs and bars in to make it perfect. Of course he was an Indy car Chief mechanic/ Indy Car owner/ Sprint car/Champ Dirt car owner He won the usac national Indy Car title with Joe Leonard driving 2 years straight THE SAME TWO YEARS WITH MARIO AND AL DRIVING CHAMP DIRT CARS HE PREPARED BETWEEN THE TWO OF THEM THEY WON EVERY RACE FOR TWO YEARS, WHAT IM GETTING AT IS HE KNOWS A LITTLE BIT ABOUT cHASSIS SETUP, HIS CAR RIDES LIKE A NEW CAR you can see the front anti roll bar but the rear is hidden under the body
What your not taking in to account is that you don't just bolt on an anti roll bar, you have to get the bar rate working with the spring rate shocks etc, on old coil over race cars i drove when we put anti roll bars on we softened the springs, had different diameter bars etc etc etc
Wonderful!!!!!!!! But.. of course... what really frosts my cookies is that NONE of this tech stuff is EVER discussed within the hobby's books or periodicals. I bet you and your dad could sell set-up sheets or write a book that would really help you ($$) and us a great deal. We can't all be engineers, but if building a rod is nothing more than bolting together parts listed in the magazine write-up or catalog because you think they make you cool, we just might be wasting our time. Man, I'd love to get a ride in that car! Thanx, Gary
There's an awful lot of misinformation and poorly engineered parts offered by street rod chassis suppliers. And I've seen some nasty dangerous cars home- built by well meaning people with insufficient knowledge. There are many good books out there that teach chassis and suspension fundamentals. Two of my faves are "How to Make Your Car Handle" by Fred Puhn, and "Chassis Engineering" by Herb Adams. All the same chassis dynamics and suspension geometry apply whether you're building a hot rod or a race car. Do yourself a favour and do the homework before you start building or modifying your ride. I'd also suggest you spend some time checking out El Polacko's Industrial Chassis website. Lots to be learned there, Steve's obviously a very creative, knowledgeable guy. Edit: Both books mentioned above are currently available on Amazon for under $17 each.
Racer5C, Forgot to add, if you could post more pix of your dad's car some time, that would be great! Interesting heat shields under the doors, and more, I reckon. Gary
Gary, many solid-axle British cars of the 1930s had front anti-roll bars. As for the mechanism of roll resistance with an early Ford transverse leaf set-up, it's a bit more complicated than it seems at first. First off, the two spring shackles, the axle, and the rest of the car together form a stable trapezoidal link system, meaning that the car will tend to rock back to the level, upright position without any exertion of springs etc. The shackles describe an instant centre a short distance below the road and in the middle of the track. Subject to lateral acceleration and consequent body roll, this instant centre will migrate in the direction of the roll motion, the effect of which being to maintain that self-correcting aspect regardless of the relative orientation of the axle and the rest of the car. If you plot it out you'll find the car will always adopt an orientation that will put the instant centre on the line of force from the rest of the car's centre of gravity. Rather, it would do so if the rest of the car were rigid, which it isn't due to the transverse leaf spring inserted between the shackles and the rest of the car. That means that while the above self-correcting geometric stuff is happening, the car is effectively deforming elastically, so that the force line from the CG is slightly off (i.e. outboard of) the instant centre. All this has a number of implications. Firstly, it explains why axles thus suspended don't freely wander from side to side even when there is no lateral-locating device like a Panhard bar present. Secondly, it accounts for a notable disconnect between roll resistance and spring rate. Thirdly, it creates the slightly weird situation that the suspension has two roll centres, neither of which has anything to do with where even otherwise respectable sources claim the roll centre is. The roll centre is not at the attachment of the spring to the frame. This is because the spring is bolted rigidly there: it might as well be two quarter-elliptics mounted heel to heel. There is no free-pivoting articulation about the mid-point of the spring that would cause the roll centre to be there. One of the two roll centres is indeed slightly below that point, i.e. half-way between the level of the spring eyes and the central mounting. The other roll centre is, of course, the instant centre I mentioned above. As I said, it's complicated. And I'm not quite sure how useful all this is for most applications. However, I've considered that it might be possible to arrange spring shackles so that they effect the sort of roll resistance one wants purely geometrically, if one introduces something to constrain the spring-eye positions to the same level relative to the frame. For instance, replace the spring with a torsionally rigid tube rotating about its own axis (which is across the frame, slightly behind the radiator) with arms on its ends, and a third arm acting on a single coil spring (which may be as soft as you'd want for ride.)
Ned, you know that expression "In one ear and out the other?" right? This is precisely why I've always wondered why smart guys like you haven't laid it all out in layman's terms yet. Ok, please correct me if I'm thinking wrong here. By my way of thinking, the only thing that really keeps the frame and body from rolling left / right on the suspension in a buggy sprung car in unwanted ways are the Ubolts that hold the springs to the frame and the stiffness of the springs? Why wouldn't adding a sway bar also help reduce the tipping? Gary PS for halfdozen... I've had the Fred Puhn's book since the 70's, but for guys like me with no formal training, at best it mostly ends up being a general guide and at worst, raises red flags for me (real or imagined). In a perfect world, we'd all be able to do the math. But I can't and I bet I'm not the only one. Some of my choices would be, go back to college and finger it out all myself (too old for that); buy a chassis well engineered, tested, refined and documented (no 1-800 chassis that I know of has been developed that way); look at photos and do what the other guys do (don't we all?); or leave the suspension bone stock (not even a dropped front axle because I have NO idea what even one little change like that actually does). The answer can't simply be it's worked for 50 years, why worry, eh?
It's the U-bolts and the centre bolt: the main thing is lateral shear. Lateral acceleration wants to slide the spring out the side of the crossmember more than pry it out. The spring stiffness plays a role but the main thing is the geometry of the shackles. The way they're set up, the car basically "hangs" in an upright position. Yes, an anti-roll bar will help, especially if you can damp it separately from the spring. I've recently been thinking about Armstrong or Delco-Lovejoy lever-arm dampers with their respective chambers connected side to side by ½" hard line. This is provided the frame is stiff enough - or more weird engineering to chase that last 5%
Many facts in this thread, I'll ad some words,you sort it out. True, stiff in front means push, stiff in back means loose, however there is roll center, roll couple and many other things that need measured and not guessed at. I worked hard to engineer my sons 4" dropped front 3 link quarter elliptic rear 29 A sedan chassis right but it is hard to get the roll couple right with a dropped axle, it ends up way low inducing front roll, the rear is easier to raise but if roll couple is off you can get an odd feeling at the limit, I need to add a front bar to correct for the roll center difference front to rear, I suspected this when plotting on paper but tried to get by, the radials add enough adhesion you don't notice it much til the edge then hang on! I'm just sayin it is a combination of geometry and spring wrighte along with corner weights that make a car handle well or not.
gnichols thanks, you saved me the effort of buying that book. I get tired of wading thru theory and math formulas, when I just need some basic setup info for different suspension types.
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