64 Dart Suspension Upgrades

72bluNblu said
Exactly. A set of 1.03" torsion bars, new bushings, a good set of shocks and decent rear springs will make a HUGE difference. Add some sway bars and decent tires and you've got a great handling car. And depending on how crazy you go with those parts you can do it for half of what just the front coilover conversion will cost.

Pretty much agree with everything here except for the 16:1 manual box and KYB's.

I run a 16:1 manual box with 275/35/18's up front with +6.5° caster on my Duster, which is my daily driver. The slow speed steering effort is obviously pretty significant and it's definitely not my favorite car to parallel park, but at anything faster than 20 mph or so it's great IMO. But that's definitely a personal preference, I wouldn't recommend 16:1 manual steering for everyone. And a Borgeson would be great regardless, no argument there. They're just expensive is all.

KYB's are trash. With undersized torsion bars it's harder to notice, but with anything over 1" they're just awful. I ran them for YEARS on my Challenger, and I attributed the stiff ride to the 1.12" torsion bars I ran on that car, just part of the deal right? Wrong. I put a set of Bilsteins on there and not only did the car handle better, but it didn't rattle my eyeballs loose either. The only change was the shocks. People underestimate how important a good set of shocks can be. The Bilstein RCD's are a great shock. The Hotchkis Fox's are even better, but I think that's more noticeable with the really large torsion bars, say 1.06" or larger.

Ride height is definitely important for handling as well. But yes, "slammed" can be just as bad or worse than having the car too high. The best suspension geometry for radial tires with the torsion bar suspension is between about 1" and 2" lower than stock, basically so the control arms are parallel to the ground. It does depend on your torsion bars though, you can lose some suspension travel lowering the car so you have to run larger torsion bars to reduce the amount of travel that's needed. And make changes to the bump stops, using a shorter lower bump stop and a taller upper bump stop helps to re-center the range of travel around the new lowered height. Tire height has an effect too, especially for a daily driver. Anything that hangs down closer than about 3.5" to 4" off the ground makes life difficult on a daily, speed bumps and parking lot to street transitions get to be a real pain in the ***. I had a similar experience with my Challenger. At one point I had it down so that my header flanges were a little less than 3.5" off the ground. The more I drove it the more I realized that was too low for what I was doing with the car, I raised it up so it was a little less than 4" to the flanges from the ground and the difference was very noticeable. Still quite a bit lower than stock, but way easier to deal with.

vntned said
So I upgraded the suspension on my '64 Dart to handle better, and this is what I have learned.

Do:
-Replace all the bushings, ball joints, and tie rod ends.
-Upgrade torsion bars to 1" bars
-KYB gas a just shocks if your cheap
-Bilstein shocks if your not cheap
-US car tool stage 2 chassis stiffening
-MP or Espo 6leaf rear springs
-Hellwig hollow sway bars front and back
-11.25" front disks
-dual pot master cylinder

Don't
-manual steering box 16:1 ratio
So this steering box does exactly what it's supposed to and does have a nice quick ratio. However, the ratio is not friendly for quick transition and greatly increase steering effort when the car has wide modern wheels and sticky tires. I'd suggest a firm feel quick ratio power box like a borgeson.

-Do not try to slam the car in search of increased handling. I did initially and had issues with bump steer and unloading the suspension in bumpy corners. Also it's hard to keep your pinion angle right and drive shaft from hitting the floor.

As you can see from the pics. I went higher and higher with mine over time. The car became significantly more enjoyable to drive.

For a true street car, suspension travel is key.

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Thank you for all of that detail y'all. That's good information.

I think I'll start with upgrading all of my shocks to bilstein and see how that feels. Currently on poorly maintained roads, I just can't do it. I avoid a shortcut to work because there's just so much rattle that's happening.

After that I'll replace my torsion bar with something like 1" or 1.06" and add in a front hellwig sway bar.

I'm considering the level 1 or level 2 chassis stiffening. I dont want to go overboard on a street car, to where it's not comfortable to drive, just want it to be more solid and deliver a little more of the power to the wheels.

My rear leaf springs right now I believe are 4 leaf, as that's what the manual lists as standard, but maybe 6 leafs and new bushings will be the way to go.

I like the idea of adding coilovers, and I know they're supposed to improve handling, but at nearly 2000 dollars for just the rear wheels, im not sure how worth it that is, given that I can replace my leaf springs for a few hundred bucks and an afternoon.

My questions then become, should I even look at adding a rear sway bar? Im not sure it would add enough, but perhaps ill be able to answer that once i've got everything else changed out. Is a tubular k-member more trouble than it's worth for a daily driver street car?

I've got front disc brakes that are sub par, and my rear drum brakes have so little power. I know wilwood makes a disc brake set for the early a bodies for both front, and rear parking brakes, that might be worthwhile.