Bars and springs match?

I am gathering a list of parts in preparation of finishing my suspension.

Car is a 70 Dart Swinger 340 auto with sbp 14" Rallys. The front suspension has been rebuilt with a rubber master kit, using the offset moog bushings in the control arms. I am planning on purchasing the PST 1.03 bars and a set of ESPO 6 leaf springs +1" over stock. I will eventually add a 1 1/8 Helwig front sway bar.

What shocks should I go with? My thought was KYB'
Will the bars and springs be an OK match, spring rate wise?

The plan for the car is a solid streeter, not auto crossing, or drag racing. Just a comfortable ride, I don't care for soft suspension.

Nobody?

@72bluNblu I thought you would chime in.

There are many different threads that have discussed the various shocks and members recommendations. You may want to consider a search for those threads. My personal opinion would be the bilsteins as the KYB have a harsher ride. Hopefully some others will chime in.

Thanks
James

I have read a lot on the subject, that is how I came up with your 1.03 bars and the espo springs. Shocks however have been all over. KYB's seem to be favored, and the bilsteins also. I cannot however, see paying $400 for shocks on a street car.

I think I will roll with the KYB's unless someone chimes in with a reason not to.

kyb are bottom of the barrel.. still have them on my car at this point but will be up grading first thing after i get this engine swap behind me...

abodyjoe said:

kyb are bottom of the barrel.. still have them on my car at this point but will be up grading first thing after i get this engine swap behind me...

Click to expand...

Oh. Is there something in between KYB and Bilstein? I want a nice ride, but $400 for shocks won't be in the budget. This won't be a daily driver, but more of a summer cruiser until the kiddos are a little older.

Well after reading this thread, I stand corrected. I guess I will have to save up some more for the Bilsteins.

Have PSTs poly graphite suspension kit and at their recommendation Blistiens shocks on my '72 Demon. Am still surprised at the comfort of the ride.
Yote

Sorry, I was at work the last couple days so I wasn't on here much.

I think you already figured it out though. KYB's and Bilsteins aren't comparable really. They're both shocks that will fit these cars but that's pretty much where the similarities end. With 1.03" torsion bars I would use the Bilsteins. They'll give you the ride that you're looking for. The KYB's are just harsh, there's no way around it. With larger bars they will straight rattle your teeth out. As I mentioned in that thread you linked, and many more like it, I kick myself for not swapping to the RCD Bilsteins on my Challenger sooner. I spent 10's of thousands of miles abusing my kidney's and fillings thinking it was just the price of large torsion bars and good handling, when the fact of the matter is that a car like my Challenger with 1.12" bars and RCD Bilsteins has a better ride quality than a car with sub-1" bars and KYB's. It's a dramatic difference.

As far as the springs and torsion bars being matched, I think you're in the ballpark. Remember these cars from the factory were seriously undersprung in the front, but in the back the factory spring rates weren't actually that far off. The Mopar Performance handling book gives spring rate recommendations of like 120 to 130 lb/in for handling, and the Mopar oval track springs are 120 lb/in. The stock XHD's are 110 lb/in and that should be pretty close to what the 6 leaf ESPO's are. I run 1.12" torsion bars (300 lb/in) on my Duster with AFCO 121 lb/in leaf springs, and it's a pretty well balanced car. I have a larger, E-body Hellwig adjustable rear sway bar on it so you could run higher rate springs than I do with 1.12's, but I wanted to have the adjustment with the rear sway bar.

1.03's and the ESPO leaf springs should be pretty well matched for your needs. If you add the Hellwig front sway bar, you should add their rear bar as well. You might use it on the lowest setting (it's adjustable and has 3), but I think you'll want to add the rear bar with the front to keep things balanced. With the +1" springs you'll have a higher roll center in the back than in the front.

Here's my experience so far, 67 dart, replaced just the rear suspension from old leafs and KYB's to oval track 120 leaf springs and single adjustable hotchkis, very very noticeable difference the whole rear of the car felt more solid and predictable. I don't know which improved it more the leaf springs or the shocks but I'm more inclined to say the shocks, I think you would be happier saving up for the RCD bilsteins, IMO.

Thank everyone. I found another thread that explained why the KYB's were a bad idea with larger bars, which I did't see at first. Thanks again @72bluNblu for re posting this again.

I will also definitely consider the rear sway to keep things balanced.

sounds like you already figured out but I can also add a bit.

I only have a very short experience driving on bilsteins now with my scamp (thanks to advice from 72bluNblu and others). Having said that its immediate and apparent that you will want these on all your cars. ha

I cheaped out on my daily (newer car) when doing suspension upgrades and went with KYBs (basically best available without spending a fortune). Now I am seriously considering throwing them in the dumpster for some expensive bilsteins for that car as well.

The bilsteins are just way more comfortable driving around and when you need them they are there. Quality pieces, you get what you pay for.