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Technical Sway bars; My brain's spinning trying to figure them out

Discussion in 'The Hokey Ass Message Board' started by atch, Sep 19, 2022.

  1. atch
    Joined: Sep 3, 2002
    Posts: 6,394

    atch
    Member

    SETUP:
    Clarence (avatar) has an Aspen-Volare front suspension. Sorry that's off topic, but the information is critical to this question. Said front set-up has a factory sway bar. It doesn't seem to be as effective as it used to be; I'll be replacing it with direct replacement. I think that this will help as it doesn't corner as well as it used to.

    I'm thinking about installing a "universal" sway bar on the rear. I see that Jeff Norwell is replacing the factory 7/8" one with a 1 1/8" sway bar on his '57 Ford. Other comments on his thread belittle the factory 7/8" bar. Jeff is doing the front whereas I'm doing the rear. His '57 and Clarence are roughly the same weight.

    I'm not as stupid as I look. I realize that front and rear are different animals. I just used Jeff as an example of bar diameters.

    I'd like this thing to corner like a Formula One car but realize that just ain't ever gonna happen.

    Clarence has the original ladder frame with (refurbished original Ford) parallel leaf springs on the rear using an 8" Ford rear. On the scales he weighs about 3,600 pounds. Unfortunately I don't remember the front/rear distribution.

    I've looked at Summit and some other suppliers. That's where the confusion has set in; there are a lot of differences.

    THE QUESTON/ADVICE REQUEST:
    Does anyone have any real-life experience with aftermarket rear say bars that would apply to my situation that would help me decide what unit to use? Or well thought out ideas?

    Diameter?
    Solid/hollow?
    Material (I ***ume they can be made from different types of steel)
    Universal or for a specific application?
    boneyard unit?
    other?

    b-t-w; I didn't find anything searching herein.
     
  2. TRENDZ
    Joined: Oct 16, 2018
    Posts: 386

    TRENDZ

    A large diameter front sway bar will improve directional traction and reduce body roll in corners. a better alternative is stiffer shocks and higher rate spring (probably not an option for you with torsion bars)
    Going with a rear sway bar that is to big will cause the rear to get loose in hard corners.
     
  3. KevKo
    Joined: Jun 25, 2009
    Posts: 1,041

    KevKo
    Member
    from Motown

    I think a unit from a mid-size SUV would work. Like and Explorer or any of the GM S-based vehicles.
     
  4. gimpyshotrods
    Joined: May 20, 2009
    Posts: 24,516

    gimpyshotrods
    ALLIANCE MEMBER

    Put a modern 1-inch bar in the front, and try that before thinking about the rear.
     
  5. Rynothealbino
    Joined: Mar 23, 2009
    Posts: 439

    Rynothealbino
    Member

    Are you trying to cure excessive body roll, or fix over / under steer? Going to generalize here and make the statement that too much front bar relative to the rear can cause understeer since body roll will tie itself more directly to front tire loading. Too much rear bar does the opposite and can induce oversteer.

    Lots of factors here. Weight distribution, roll centers, tire size, alignment, spring rates, damping, etc... More details will get better advise.
     
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  6. pprather
    Joined: Jan 10, 2007
    Posts: 8,968

    pprather
    Member

    Front bar is less affective than it used to be, sounds like bushings and other connectors need to be replaced.
    That's where I'd start.
     
  7. Blues4U
    Joined: Oct 1, 2015
    Posts: 8,068

    Blues4U
    Member
    from So Cal

    Yeah, steel bars don't lose their effectiveness. I suspect it was never very effective and you've come to realize that.
     
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  8. blue 49
    Joined: Dec 24, 2006
    Posts: 2,126

    blue 49
    Member
    from Iowa

    Shocks and sway bars can only be as effective as they're supposed to be is if they're mounted to a rigid frame.

    Gary
     
    dana barlow likes this.
  9. The one caution I will make is DO NOT use a bar that attaches to the rear axle housing. With only a few exceptions, when Ford factory-installs rear bars they mount the bar to the body/frame and use links down to the axle to next to the suspension points. This is to prevent bending the housing, and before you scoff, it happened to me. There was zero doubt the bar caused it. Years ago I had Art Morrison slightly narrow a 9" housing for me, reinstalled with a Addco rear bar that mounted to the axle housing. This was done with a fixture and the axle should have been straight. Within 5K miles it started eating axle bearings. After replacing several and still having failures, I pulled the housing and took it back to Morrison. It was bent, he figured he screwed up and straightened it again. He verified in front of me that it was straight, back in it went. 5K, more bearing failures. Pulled it AGAIN, back to Morrison; yep, it's bent again. No freeby this time... Back in minus the rear bar, no more problems.

    The exceptions are the 9" axle housings Ford used in trucks and the larger rear-coil-sprung cars where Ford did mount the bar to the axle housing. You'll be taking your chances with any others, especially the medium-duty 8".
     
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  10. Rex_A_Lott
    Joined: Feb 5, 2007
    Posts: 1,158

    Rex_A_Lott
    Member

    I used to race dirt cars where we were supposed to use stock parts. Look around a little and find the biggest front sway bar you can find, they often made a factory bar for police cars and station wagons that was bigger. There used to be the Hollander interchange manual that would get you a cross reference for what you could look under.
    Get you a set of stock mount racing shocks, Bilstein, Carrera, Pro etc. The shocks will make more difference than anything. In the overall picture, what you do to the rear will have little effect for the money spent. Good Luck.
     
  11. pprather
    Joined: Jan 10, 2007
    Posts: 8,968

    pprather
    Member

    What front shocks are installed? Shocks can make a big difference in ride and handling.
     
  12. atch
    Joined: Sep 3, 2002
    Posts: 6,394

    atch
    Member

    Thanx to everyone for your input. I appreciate you taking your time to do so. I'll replace front shocks & bushings and, for the time being, forget the rear sway bar. Also I'll see if I can get a police or station wagon "factory" front sway bar.

    Any suggestions where I should go looking for such a sway bar? Bushings and links are a piece-o-cake but who can supply the police sway bar? So far I haven't been able to locate one.

    EDIT: I refined my searches and found some. However, I'm open to additional suggestions for suppliers.
     
    Rand Man likes this.
  13. lostone
    Joined: Oct 13, 2013
    Posts: 3,597

    lostone
    Member
    from kansas

    I'm with all the gents above, first- the stock bar shouldn't loose any "feel" to it. So check bushings and parts first. Especially on the lower inner arm bushings, mopar had problems with these, if possible check those bushings with weight on the front suspension. The bushings will show deflection with the weight on them, take the weight off and the deflection will seem negligible.

    Also agree, find a police car, station wagon and measure that sway bar, if bigger use it.

    On shocks, I'm going against the grain here but on older suspensions I prefer oil shocks over gas charged, I like the ride much better UNLESS you chose bilsteins self adjusting shocks, those I really like. And add matching shocks to the rear.

    Again with above comments, do these 3 things and I bet it drives a whole lot better and tighter and you won't have to worry about a rear sway bar.

    Also have it aligned and try to get the caster around 3 degrees positive with around 0 camber.

    .
     
  14. Rex_A_Lott
    Joined: Feb 5, 2007
    Posts: 1,158

    Rex_A_Lott
    Member

    Look around and try to find somebody racing, or used to race, asphalt in a Street Stock type cl***. They may have or know of somebody that has worked with a car with the same type suspension you have. They may have old parts laying around or know where to get them. I ***ure you they have spent much time and money trying to figure this all out. We used to crawl the junkyards, but this was the '90's, a lot of that has been crushed since then.
    Speedway used to sell shocks and such. In fact they had another whole company that wholesaled parts to the local racing shops, back when there was such a thing.
    Since we are talking suspensions, I had an OT '75 Nova that I drove daily for a while. I put a bigger bar and a set of stock mount Carrera racing shocks on the front and it made a huge difference in the way it cornered. I cant remember if the bar was 1 1/8 or 1 1/4, but it was the biggest thing I could find at the time.
    I agree with putting a little positive caster in it, it will give it more "feel", but you better have power steering.
    Good Luck
     
  15. 57 Fargo
    Joined: Jan 22, 2012
    Posts: 6,182

    57 Fargo
    Member

    You know gas charged shocks still have oil in them right? The gas charge is on top of the oil to prevent aeration of the oil.
     
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  16. lostone
    Joined: Oct 13, 2013
    Posts: 3,597

    lostone
    Member
    from kansas

    Yep, just don't like the firmness of the ride on older suspensions.

    The older suspension doesn't seem to react as fast as the newer suspensions due to softer and in some cases larger bushings thus the stiffness of the gas charged shock is felt quicker and more harshly.

    .
     
  17. Dan Timberlake
    Joined: Apr 28, 2010
    Posts: 1,578

    Dan Timberlake
    Member

    typical 50s and 60s Murcan car handling was all about comfort and straight line "stability" . heavy understeer can do that.
    Sometimes advertised hi-tech features were goofy camber curves that kept the track width constant for less scrubbing and better tire wear.

    When the 442 first came out the road tests raved about its "handling" compared to compe***ors and especially its GM brethren. I do not know about the 442 spring rates etc, but a rear bar was added.
    I believe a small rear bar will make a noticeable reduction in understeer, and make the steering feel more responsive. Not quite quicker steering, but kind of like that.
     
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  18. G-son
    Joined: Dec 19, 2012
    Posts: 1,490

    G-son
    Member
    from Sweden

    Mostly a matter of weight. The metal in the center makes very little impact on the stiffness, so removing it and making it a tube instead saves weight without changing the stiffness very much - perhaps a small increase in outer diameter is required to get the same stiffness, but the difference should be small.

    As you don't seem to know what you really want/need, how about something with adjustable stiffness? The picture is of an adjustable blade on one end of a sway bar, turned one way the thin blade will be very flexible, turned 90 degrees it will be very stiff. Changing the attachment points on a regular style bar to change the length of the lever could also be used as an adjustment.

    [​IMG]
     
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  19. charleyw
    Joined: Aug 5, 2006
    Posts: 2,321

    charleyw
    ALLIANCE MEMBER

    Check out the old Ch***is engineering offer. I installed one on my F-1, works well (certainly mine isn't pushed hard though) I can measure if you like. I can't remember who bought their line or at least part of it.
     
  20. Adding or upsizing a front bar results in "understeer" so in spirited driving, the front will plow and go wide in a turn.
    Adding or upsizing a rear bar results in "oversteer" which causes the front to turn in much more sharply. Too much rear bar/oversteer and the front will track inside the line through the turn while the back end will still tend to follow the line. This looks and feels like the back end is swinging wide and in a practical sense, it is because that's how "spinouts" happen. A savvy driver, with developed reflexes, can keep control by slightly turning to the outside of the 'drift' keeping the front ahead of the wide swinging back. To quote Doc Hudson in the Cars movie, "Turn right to go left". We call it "a 4-wheel drift out of a turn" but actually, only the rear is drifting and the skilled driver is dialing in enough correction to 'drive' the front ahead of the line that the rear is drifting.
    Replacing rubber bushings with 'poly" is like going with a bigger bar but the cost is likely a harsher ride.
    Factory-equipped vehicles are most often set up with some understeer and will "plow" somewhat in front because that's safer for the unwashed m***es.

    Short video........
    https://whitelineperformance.com/blogs/whiteline-blog/oversteer-and-understeer-explained
     
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  21. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 5,354

    ekimneirbo
    Member
    from Brooks Ky

    I'd look in the "pull-a-part" junkyards for a Saturn Vue SUV. They have a nice compact rear sway bar. One of the things you have to consider is if there is room, and the small bar is from an SUV so it has something (kinda) in common with your panel truck. Its possible that a perfect sway bar might have even more resistance than the Saturn does, but it should be "fittable" and add a modi*** of additional control. And the one I bought for a pickup truck addition was pretty cheap.
     
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  22. Budget36
    Joined: Nov 29, 2014
    Posts: 15,303

    Budget36
    Member

    When my OT was a bit sluggish on cornering, I took advice from many on a different forum and put in polyurethane bushings for the front sway bar and whatever the things that hang down are called (yes I am suspension illiterate). Seemed better than new.
     
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  23. Rand Man
    Joined: Aug 23, 2004
    Posts: 5,375

    Rand Man
    Member

    I agree with the the comments. Check your bushings. I put a heavy bar on my 57 Chevy. Really made a difference.
     
  24. 57 Fargo
    Joined: Jan 22, 2012
    Posts: 6,182

    57 Fargo
    Member

    First of all I’m discussing and not arguing….

    I would say any firmness is a result of picking the wrong shock with the wrong valving, gas charged shocks can be as firm or as soft as any other. Now with a “replacement” shock there is no guarantee that they are the same valving that the car should have. The gas charged shocks also won’t “fade” like a non charged shock so it’s possible that they maintain their “firmness” unlike a traditional shock that starts to lose its dampening ability as it warms up.

    Good discussion, I feel like shocks are often misunderstood or ignored by a lot of people.
     
  25. lostone
    Joined: Oct 13, 2013
    Posts: 3,597

    lostone
    Member
    from kansas

    I work in a frame and alignment shop, been there 37 yrs and another 5 yrs at another place so I'm just sharing my experiences.

    On the older cars, say 80's down on certain models and just about all of them from the 70's down I hear alot of the same complaints.

    People will come in wanting urethane bushings and or gas charged shocks on their cars only to come back later complaining of a noisy, harsh or rough ride. The lighter the cars the more prevalent the problems seem to be.

    Usually on the gas charged side its always a "sharper" feel to bumps and pot holes for lack of a better word is what they complain about and interestingly enough it's usually the older crowd.

    Now I hardly have any complaints with the bilsteins, I think it's because of its self adjusting gas valves. Honestly I don't think many of the shock suppliers do much to improve valving vehicle to vehicle, kinda a couple sizes fits all.

    I went thru the "urethane" phase on 2 separate cars, my 68 firebird and my 71 grand prix. in the 68 the suspension would just beat you to death and noisy, Monroe gas charged front and rear added and that just made it worse so after a year I tore it all out out and went back with new performance rubber bushings and performance shocks, it was a joy to drive again.

    The grand prix was a different story, it was alot stiffer ride but noisy and once that heavy car started to wear on those bushings and they picked up a little play it didn't take long for that heavy car to beat those bushings to death. So after about 16 to 18 months out came all the urethane and heavy performance rubber bushings and oil filled shocks went back in. Never looked back at either decision.

    Now understand I drove my cars hard, driving thru the hills of Southern Missouri every weekend, hard enough that there are several times I had new front tires last about 8000 miles, not just due to wear but I would actually roll the tread face off of the carc*** of the tire. Uniroyals, cooper's, it didn't matter, I showed no prejudice against any tire manufacturer. My boss would just shake his head.
     
  26. atch
    Joined: Sep 3, 2002
    Posts: 6,394

    atch
    Member

    I'm reading and learning every time someone posts...
     
  27. 57 Fargo
    Joined: Jan 22, 2012
    Posts: 6,182

    57 Fargo
    Member

    I think we are basically saying the same thing, the torsialastic bushings from factory are designed to be “squishy”. Urethane will absolutely be harsher! I couldn’t agree more about generic shock valving, not at all Tailored for each model. Any adjustable shock is going to be way better whether self adjusting or manual, I think you also get what you pay for, sometimes.
     
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  28. lostone
    Joined: Oct 13, 2013
    Posts: 3,597

    lostone
    Member
    from kansas

    Yep! I always enjoy a good discussion!

    Like I stated before opinions will differ but like I said thru my experience alot of people regretted the harsher ride.

    One thing I do like about sway bars is that they usually don't effect ride quality over everyday driving just under corner loading.

    One thing about shocks is if you don't like them it's not a extremely hard job to change but can be an expensive change!

    Urethane bushings on the other hand can be both expensive and hard to change.

    .
     
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  29. pprather
    Joined: Jan 10, 2007
    Posts: 8,968

    pprather
    Member

    Rubber bushings. Bilstein shocks.
    Done.
     
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  30. gene-koning
    Joined: Oct 28, 2016
    Posts: 5,782

    gene-koning
    Member

    Ah, the good old Aspen/Volari K member!
    I actually raced those things on dirt tracks!
    Almost everything on the front suspension was mounted in rubber (it was all about the ride quality at that time), but there are a few other points to look at:

    Depending on how the K member was installed onto your frame, the original upper control arms were mounted to a formed steel plate that bolted to the K member, the had the upper control arms bolted on to them. Under hard racing conditions (like the many road miles, and time the K member was attached to your frame), those bolt on brackets would start to flex, and quite obviously the handling would go away. Again, some of the K member installations eliminated those rackets, but some still used them. If they are still on your frame, you might want to pull them off and take a look at them to be sure they don't show cracks, or indicate fatigue.

    Another thing concerning the installation of the K member to the Ford frame is going to be how it was mounted. Two different approaches were primarily used, one method used sheet steel to bridge the gap (or the frame was cut to eliminate the gap), you want to be sure to check the condition of that welded joint, time may not have treated it well.

    The 2nd primary method of joining the frame and K member was to add pockets to the frame and use the Mopar rubber bushings and bolts. If there is rubber between the frame and the K member, it at least needs to be replaced with new rubber, or replaced with solid steel or aluminum pucks.

    Beyond that you really probably need to replace the bushings that hold the torsion bars to the lower control arms, the condition of the lower control arm bushings, and the condition of the upper control arm bushings. There should also rubber bushings at the other end of the torsion bars, or the torsion bar crossmember (if it was used on your application) that will need to be looked at and likely replaced.

    Incase you didn't know, the Aspen/Volari K member was also used under the 81-88 Diplomats (often used as police cars) and 5th Ave cars, and 80-82 Dodge Mirada & 80-82 Chrysler Cordoba, and the 78-80 full sized Lebaron (and a Plymouth version that escapes my memory right now) Chrysler called the K member an F, J, & M body crossmember, could expand your search. Most of the Diplomat police cars had factory real sway bars, but Chrysler stated that the rear sway bars and leaf springs were to be used as as set (don't really know if that really means anything though).

    Then change the shocks.
    Gene
     
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