i think its time to upgrade suspension, any suggestions?

[Sport340]

I have a74 Dart Sport and while it handles....OK. i want it to handle better.
its a street car so i need to be able to take turns without swinging out my back end hehehe

any suggestions as to where iw ould see the best improvement?

thanks.

[Canuck Dart]

I'd be interested in the same info for my '73

------------------
1973 Dart 340 Sport

[gthomas]

Suspension upgrades for older cars, check out PST at http://www.p-s-t.com/index.html
I'm also thinking of upgrading the cornering ability for my Duster.

------------------
1972 340 Duster
-Dyno @ 420hp/440ftlbstq
-Built 727 w/3000 stall
-3000lbs
1999 2500 4x4
-V10 w/5sp
-Manual xfer case

[451Mopar]

I rebuilt the entire suspension of my '71 Charger with the PST Poly-Graphite bushings and KYB gas shocks.
They helped take some of the slop out of the suspension, and replaced old worn-out parts, but the car still swayed in the corners and rode fairly soft.
I put the PST sway bars on and that helped the car corner flatter, but the ride was still fairly soft on the 4200 pound car.
Then I put the Mopar "street handling" Torsen bars on. These are a bit stiff, but really nice for a "sport" suspension feel. Now I can go over dips with out smashing the oil pan, and the car handles better than the 235x60x14" tires can control (scuffing the sidewalls through a solomn course.) So I upgraded to 255x60x15 tires on 15x7" rims (I could have went larger, but that was the sizes in stock at the time.)
I also had the stock rear springs rebuilt with an extra leaf added to stiffen the rear. This really helped with traction since the extra leaf has full forward bias in the spring pack, which stiffens the front section of the spring sort of like the super stock springs.
The only suspension part not upgraded is the old slow ratio Power Steering box which I plan to replace some day

[Keith]

My story is almost identical to 451Mopar's, except in a 67 cuda w/ 340.

Here is what I did: PST front & rear sway bars, front end rebuild kit w/ polygraphite. At the time they didn't have the 'super' front end kit but I ended up needing everything in it anyway + pitman arm. I went with MP's torsion bar with the diameter that was stock on a 383 car. I can't remeber if it was the .89 or .93". I can look it up if you're interested.

I went with the MP shocks since they were cheaper although I will probably go to KYB someday and see if I like them.

I also had those exact same tires- 235/60R14. They were terrible on the skinny rims I had. The next summer I bought 16x7" rims and 225 series tires and that helped a lot!

My car is a street car and I really like the way it handles. I never feel like the back end is about to come loose and I always look forward to cloverleafs on the Hiway. Sometimes I take them just for fun.

And I also would like to upgrade the steering box. I'll probably get a firm feel box sometime in the few years.

When you're done its essential get a good aligment from someone who knows how to do old mopars.

[72Challenger]

Your best improvement for the money is definitely the polygraphite bushings, especially if there's any wear at all in your existing ones. Then the sway bars, then stiffer springs. Obviously the widest tires that will fit, with the stickiest compound you can afford. The best-handling tires are only offered in 16" and larger, though. Not everyone likes that look on their old mopars. The steering box upgrade will help feel, not absolute cornering force, but still definitely worthwhile.

Keep in mind that oversteer (swinging out the back end) occurs from a mismatch in slip angles from front to rear, no matter how well the car handles otherwise. That is, a good, stiff, tight suspension that generates very high G's in a turn can still break one end loose before the other. Getting this right is part of suspension tuning. Also, high horsepower rear wheel drive cars can induce oversteer by getting on the gas during a turn. Done right, this can be good. Done wrong, you'll make your local bodyshop man very rich.