My dart has the smallest diameter torsion bars. I read that lots of people upgrade to thicker bars for better handling. I have a Slant 6. Mine were cranked up pretty high, so pretty firm ride already. That said, I'd likely want a bit lower ride but the same firmness.

Q: what diameter bars should I use? 0.89" diameter sufficient? I have upgraded the rear to 8 3/4 rear end and a bit stiffer leaf springs. I will be installing disk brakes upfront, LBP 15" wheels, and a sway bar (at least in the front).

thanks all,

brian

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One can crank'em up until adjusting bolt bottoms out, but the spring rate is still the same, as is the weight of the car. Softer torsion bars allow suspension to move with less forces applied translating to longer suspension swings when rolling down the road.

When a stiffer bar is installed it is able to better resist dynamic suspension movement caused when vehicle encounters undulating road surface, or hard braking nose dive, and static loading such as the heft of one's backside and other dunnage onboard.

If you have stiffened up the rear springs, than stiffing the front spring rate would be the way to go. I think the consensus here is relatively softer rear spring compared to front rate is apt to produce more of a tendency to under-steer, and the other way around makes the rearend want to step out or over steer.

These cars are very softly sprung from the factory compared to today's cars, and are somewhat sloppy wallowing hogs in factory dress.

Stiffer torsion bars, and front only anti swaybar will bring an A Body close to modern handling when added to all ready stiffer rear springs.

My car has six leaf rear springs, 1 1/4" sway bar, from Firm Feel 0.940" bars with all new suspension bushings, a recently rebuilt stage II power steering box which has closer to modern feel. The car rides a bit softer than my '07 Chrysler 300 C AWD, and has no leaning, brake dive, or suspension bottoming out with a comfortable ride.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Another school of thought is to keep the soft bars and add a big sway bar and high quality shocks.

The sway bar alone stiffens things up,,,,,and the shocks give you rebound control.

The part of the world I live in is too rough for big bars AND sway bar.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

For a high-end data point, I can say that 1.12" torsion bars will be uncomfortably stiff, at least on typical American roads. I probably wouldn't go higher than 1", especially if you're also adding a sway bar.

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Somehow I ended up owning three 1964 slant six A-bodies. I race one of them.
Escape Velocity Racing

Great feedback.

I did add KYB shocks (all around) and that seems to have made a huge difference in the front.

I think I'll go with the bit thicker T-bars when I finally redo the front suspension and brakes. I have swapped out to the '73-76 K-frame, but I'm not ready to do the rest yet (still need spindles, some brake hardware and such). I'll also swap out the rear axles so I can go to LBP. For now I'm just using the existing LCA/UCA's, on the new K-frame, no sway bar tabs on the old LCA's. I have the factory LCA's with tabs rebuilt, slop taken out, plates welded on, but I guess it wouldn't be hard to weld some tabs on the old ones while I build up parts just to see how a sway bar feels on there...I'm considering that. I have a factory sway bar for the new K-frame configuration; might be nice to try it out (may go to tubular (thicker) later if anyone thinks that's a better option).

brian

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My personal experience. If your going with KYB's I wouldn't go much beyond stock. I have two similarly setup cars. One with bilstiens and 0.920" (or was it 940's?) and one with KYB's and 0.890" bars. Both with firmfeel's sway bar. The car with the bilstiens and larger bars actually has a much smoother ride.

Yes, I think all your feedback tells me that 0.94's are the way to go, don't need anything more than that...

thanks again, all.

brian

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I can hit up my family for my birthday, they've been buying me dart parts for the past couple years for b-days and Christmas...I love my family... Makes my lists easy to draft, I simply recall my mental list-o-parts for the dart and voila!, instant gift list. I'm sure they appreciate how easy it is; I even give them the source - no brainer!

My wife bought me the Firm Feel sector support kit for Christmas. She told me when she called, the voice on the other end said: "Firm Feel, Dick speaking.." she busted out laughing, then gained her composure and continued on with the order...

brian

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These are my wife and her brother and his wife...they know absolutely nothing about cars, so they have no earthly idea what I'm asking for other than it is a car part. I open my sector support on Christmas with glee; they look at me like "whatever, he's happy with his car part...." All the gearheads in my family are on the east coast in PA.

brian

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