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1972 Plymouth Road Runner 440/4Spd - Torsion Bar Replacement

4

4404ME

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Ok, I would appreciate some input here, please.

IF you were going to replace your torsion bars, would you go with PST, Firm Feel, or...

To my knowledge, my stock bars are .880 Dia., with PST I have a 1.03" option, with FF 1.06 in staying close to the PST bar. Mostly normal street driving, but want the extra firmness, and I have already purchased Bilstein front shocks. I may replace the Rr springs at some point, but I have good shocks in the rear. Thanks!
 
I’m no expert - some people freak out on anything over a Hemi/440 bar but I put the PST 1.03” on my 66 Hemi Satellite and it rides pretty gentle and compliant. I don’t believe I would want anything on it with a lesser spring rate.
 
I'm about to install Hotchkiss 1.03" into mine after reading a number of threads here debating bar size. The takeaway I got was that this size is a bit stiffer than the stock 440/Hemi bars, good for street & you have room to play with the adjusters.

The main reason I settled on Hotchkiss is that they were available from a Canadian distributor with free shipping. I considered the other brands, but no one in Canada sells them & shipping costs from the USA on heavy items is ridiculous.
 
I can not speak for PST 1.03 torsion bars, but over the past year I completely redid my front end with mainly stock rubber parts on my 70 RR. I used urethane on the lower control arm shafts and sway bar. I did tons of research and decided to go with hemi (.93 I think) torsion bars from classic industries. I did get bilstein shocks front and back from PST. I've been out cruising around the past week and there is a noticeable difference in the ride. It is not too firm and handles well. I am only cruising in it for the back on the road shakedown so I can not speak to hard cornering. But, I have yet to feel that classic mopar bang going over bumps so I am VERY happy with the results. I did everything all at once so I'm not sure of what individually made a difference, but overall it feels much better than I remember them feeling in the 70s/80s.
 
I have PST's 1.03" bars on all 3 of my cars. Best bang for the buck imo.
 
4404ME, Keep in mind it's not ONLY the bar diameter that matters. The spring rate depends on the metallurgy and forging process used to make them. IMHO comparing Mopar bars to any of the aftermarket bars is not apples to apples. Even the older versions of Mopar to current Mopar is questionable.
 
66Satellite47 said:
4404ME, Keep in mind it's not ONLY the bar diameter that matters. The spring rate depends on the metallurgy and forging process used to make them. IMHO comparing Mopar bars to any of the aftermarket bars is not apples to apples. Even the older versions of Mopar to current Mopar is questionable.
Click to expand...
While what you say is true, the Youngs modulus of steel doesn't vary that much (about 15% from strongest to weakest). Unless you're getting into very specific tuning of spring rates for a race car, the diameter of the bar affects the spring rate waaaaayyyy more than the metallurgy of it (30%+ in the op's case).
 
Rusty knuckles said:
While what you say is true, the Youngs modulus of steel doesn't vary that much (about 15% from strongest to weakest). Unless you're getting into very specific tuning of spring rates for a race car, the diameter of the bar affects the spring rate waaaaayyyy more than the metallurgy of it (30%+ in the op's case).
Click to expand...

When you say strong to weak, does that equate to torsional resistance?
 
66Satellite47 said:
When you say strong to weak, does that equate to torsional resistance?
Click to expand...
Referring specifically to Youngs modulus which goes into the equation for calculating spring rate. Ranges from about 28,000ksi to 31,000ksi in various steel. So metallurgy will have an effect yes. But minimal compared to diameter change.
 
Hello All, I just want to say 'Thanks' to everyone who took the time to reply! I found it all to be of value!
 
We used to offer varying sizes of torsion bars, but over the years we found our 1.03 to be the most popular among the B & E bodies. They are ideal for customers looking for firm and modern feel that is not harsh. Plus as a member of the forum you would be eligible for the FBBO discount. We also have the boots, clips and adjusters if need be. If you have any questions please feel free to reach out to me via PM.

Thanks
James From
PST
 
Firm Feel here.
 
Geff McCarthy said:
look for bars for sale in this forum. AFAIK, they don't deteriorate.
Click to expand...
Mine were from a PA car, pitted with metal/rust chunks coming off. I read posts saying that since they are springs that any missing part of the bar is dangerous. That was good enough for me (or a really good excuse to spend more money) to upgrade.
 
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