Rear sway bar opinions (Found a good deal 118.95 ship free.)

[b5blue]

  Opinions please: Mostly stock 70 440 Charger that I'm adding subframe connectors to. Would adding rear sway bar (Keeping stock bar up front.) be "better" than just getting bigger bar up front? Did factory ever offer a rear sway bar on 2nd gen. or any B Body?
 I'm looking to flatten out cornering somewhat but not build a G Machine.  

[cdr]

No factory rear bar on 2nd gen Charger, I have the large front & rear Hotchkis , the rear is adjustable & I like that, I like the way it bolts on, no drilling, I like the way it goes to the rear of the car staying out of the way of the exhaust.

[Mike DC]

  
Definitely don't add a bigger sway bar up front alone.  The car already under-steers mildly with the factory setup and that would push it farther in that direction.  

(The end of the car with the stiffer roll resistance is the one that slides sooner.  Sort of contrary to your instinct.)


A small rear sway bar wouldn't be a bad idea.  But definitely keep it small.  Don't add a big rear sway bar unless you're also making the front one even bigger.


The idea is to keep the front & rear roll resistance coordinated.  Getting either end too far out of whack with the other is bad.  That's worse than the whole car being too soft or stiff overall.  

The corner springs (torsion bars and leafs) play into this as well. The factory used a pretty big front sway bar + no rear sway bar, because that was needed to balance the rates they chose for the leafs & T-bars.  The stock (R/T) leafs were very stiff and the T-bars were very soft.  In hindsight the T-bars & leafs should be closer together in rate.  The factory's soft T-bars being the worst offender.  

[JR]

The rear sway bar was one of the most notable handling upgrades I made. It instantly helped to dial out understeer.

I have the three way adjustable helwig bar. Along with the matching big bar up front. Love em.

[303 Mopar]

I added a big sway bar from PST up front and the Hotchkis rear bar like CDR and it made a big difference in handling.  I also added a Stage III steering box from Firm Feel and steel tube frame connectors, which I would highly recommend too.

[375instroke]

I agree with what miked said.  To me, it seems that the fronts were so undersprung, that the theory of increased stiffness increases understeer goes out the window.  The tires are all over the place, pointing in the wrong direction, and cambered so much, the car is driving on the hubcaps.  In addition to that, once you bottom out the suspension, spring rate goes to infinity, and the tire brakes loose anyways, so you need to keep that in check first.  Check this out for example: BUD LINDEMANN ROAD TEST 1969 DODGE CHARGER 500 426 HEMI  You want to run the softest suspension you can get away with, and that's usually not that soft in front on a car with 40%/60% weight distribution.  Generally, you want understeer over oversteer, and adding just the rear bar may give you oversteer.  I've had two racecars where the back was too stiff, and I can tell you, oversteer at over 100MPH in turns is not fun.  For my street car, '69 Charger R/T, I added 1.04" front bars, Firm Feel 1-1/8" front bar, QA1 adjustable shocks, and stock Hemi leafs.  With shitty BFG TA tires, the car takes all I'm willing to risk giving it with no sign of understeer, oversteer, or bumpsteer.  I have a rear bar that I haven't put on yet, but at this point, I think tires are my Achilles heel.  Can you just get a larger front bar, too, or are there budget constraints?

[Mike DC]

                      
Yep.  The conversation starts with the tire grip.  That affects the choices for everything else.  Grippier tires = everything has to be stiffer to prevent body roll/lean.  "Everything" includes springs/shocks/bars, all the way up to the unibody stiffness.  

To understand the too-stiff issue, think of driving a car on ice.  That wipes away most of your tire grip.  

Now the springs/shocks/bars are SO stiff (in proportion to the tire grip) that you cannot feel where the limit is.  You don't get enough warning before the grip suddenly lets go.  You would have an easier time driving the car on ice if everything was a bit softer.  A softer chassis would help you feel how close to the edge it is.        

---------------

Those old Bud Lindemann road tests are so interesting.  I would pay money for a whole collection of those with higher video quality.    

Look at how that C500 Hemi is sliding & drifting around on that track in the video test.  Would that car benefit from a modern suspension stiffening overhaul?  I doubt it, not on those OEM tires.  

There is arguably room to stiffen it up a little.  Not very much.  And the OEMs err on the soft side to keep most amateur drivers (including us) out of trouble.  (Street cars that corner totally flat will look cool, feel cool, and get wrecked a lot.)

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Exception to all this:  unibody stiffness.  More of that is better, period.  
Same with stiffness for the "hard" pieces like control arms & spindles & axle housings.

(Yeah, okay, there is a point of diminishing returns on this too.  But it's so high that un-caged street cars will never come near it.)

[b5blue]

  Thanks for the feedback guys. With 255/60's mounted on 15X8 Torq Thrust D's on all four corners, Monroe-Matic shocks and Mopar Performance R/T spec. T-bars and springs the car rides nice and alignment got pretty close to ideal with offset (staggered) UCA bushings and adjustable strut rods. With no intent of doing any "Cannon Ball Runs" and drag race days behind I noticed E Body cars had rear sways available and thought possibly B's did also. Over 23 years I've logged 1,000's of miles and like how comfortable a B body rides. 

[Kern Dog]

You could write a book on this subject.
In short, a LOT of it comes down to "Roll compliance".  By roll, I refer to the body lean of the front of the car versus the rear.  If the front end has a greater amount of stiffness, it will lose traction first. If the leaf springs are stiff and you add a rear sway bar, the rear will lose traction first.
As stated, a car that loses traction at the rear first exhibits oversteer. This can happen faster than you can react and BOOM, you just spun out. AVOID this.
I've mixed and matched parts on these cars for years and still learn new things.
My Charger has had stock .88 torsion bars, 1.0 and currently has 1.15s. The leafs were stock 4 section units at first but since 2004 have been Mopar Performance 440/Hemi spec with 6 leafs each side. When I had the 1.0 t bars, a 1.125 front bar and the MP leafs and a 7/8" rear bar, the car was REALLY twitchy. The ass end wanted to come around during rapid steering input. The fix? ADD spring rate to the front and remove some from the rear.
I added the 1.15 t bars, a 1.25 front sway bar and replaced the 7/8" rear bar with a 3/4" bar with longer lever arms. The car handles neutral now. I can kick the tail out with the throttle though, just the way I like it!

[alfaitalia]

Cool video ....7 miles per gallon.....LOL! He would have stopped that a whole load quicker if he had backed off the brakes a bit....skidding is just sliding.....not braking!!

[b5blue]

  Thanks Kern, with my ride height stock spec. and the tire/wheel combo sort of new I've fiddled with things enough to think the rear could use a bit of roll resistance. (Along the order of 3/4 bar.) I maintain stock ride height for daily use to handle deep puddles, potholes and such. 

[Mike DC]

Cool video 2thumbs....7 miles per gallon.....LOL! He would have stopped that a whole load quicker if he had backed off the brakes a bit....skidding is just sliding.....not braking!!

Those original tires didn't help mileage any better than they helped tire grip.  Radials got another MPG or two.  It helped encourage the switch over.

People tend to underestimate the effect of tires on mileage.  Everyone thinks about tread life when it comes to choosing "efficient" tires, but focusing on getting a tire with the lowest rolling resistance will probably save you more money over the life of it.   



The stopping tests were always done with that style 50 years ago.  I don't know when they changed to trying to modulate the brakes.  

It's tempting to say it doesn't test anything but tire contact patch size.  However the brakes were so much less potent back then, especially once the drums started fading . . . they really could not assume any car would be able to lock the wheels up at-will.  That's a safer assumption now.

The old testing style was probably more accurate for how the average unskilled driver does it.  And with ABS brakes we're basically back to that again - forget braking modulation skill, just stomp and pray.

[375instroke]

I think they were called panic stops.

[b5blue]

I've seen clips of driving from the late 40's early 50's, pumping brake clearly demonstrated. 

[b5blue]

Digging around I find the Addco RSB 919 actually use to be a Mopar Performance part, it has a disc. part number.  It also looks to be best suited for my setup with a 3/4" bar.

[b5blue]

Good price and a sale with free shipping is hard to beat.
   https://www.sdtrucksprings.com/index.php?main_page=advanced_search_result&search_in_description=1&keyword=addco+919

[Kern Dog]

I added a big sway bar from PST up front and the Hotchkis rear bar like CDR and it made a big difference in handling.  I also added a Stage III steering box from Firm Feel and steel tube frame connectors, which I would highly recommend too.

The Firm Feel Stage 3 steering box in my car has felt sloppy for awhile. I had suspected the coupler to have some slop but it always feels snug.
Still, the loose feeling on center or more specifically, from the 11:00 to 1:00 positions always annoyed me. I could turn the steering shaft by hand with the engine off and see a fair amount of movement before the pitman arm started to move. The splined shaft on the steering box moved in and out with the rotation of the steering shaft too. Today I adjusted the nut and screw on top. The 3/4" nut was cracked loose and the slotted screw was turned about 1/4 turn clockwise, then it would not move any more. I tightened down the 3/4" nut and drove the car. The slop is greatly reduced but a little still remains. I wonder if this means that I am at the end of what can be done with this box. I have considered a Borgeson box for the car so maybe I'll use this FF box in another car.

[c00nhunterjoe]

I added a big sway bar from PST up front and the Hotchkis rear bar like CDR and it made a big difference in handling.  I also added a Stage III steering box from Firm Feel and steel tube frame connectors, which I would highly recommend too.

The Firm Feel Stage 3 steering box in my car has felt sloppy for awhile. I had suspected the coupler to have some slop but it always feels snug.
Still, the loose feeling on center or more specifically, from the 11:00 to 1:00 positions always annoyed me. I could turn the steering shaft by hand with the engine off and see a fair amount of movement before the pitman arm started to move. The splined shaft on the steering box moved in and out with the rotation of the steering shaft too. Today I adjusted the nut and screw on top. The 3/4" nut was cracked loose and the slotted screw was turned about 1/4 turn clockwise, then it would not move any more. I tightened down the 3/4" nut and drove the car. The slop is greatly reduced but a little still remains. I wonder if this means that I am at the end of what can be done with this box. I have considered a Borgeson box for the car so maybe I'll use this FF box in another car.

I would call firm feel. My 50 yo stock box has 0 play in it.

[Kern Dog]

You are likely to be the only one. 
My guess is that you have skinny drag racer type front tires? I'm running a 275-40-18 and that wide of a tire will surely reveal any slop in the steering due to the increased effort needed to turn them.