Most TBs are rated by diameter, what about spring rate.

[green69rt]

I starting to think about what to buy for the suspension on the project and see a lot of TBs out there.  Almost all are rated by diameter, .92, 0.94, 1.00, etc.  Does this correspond to spring rate??  Just checking to make sure.   I'm looking to use a 1.00" bar. Seems to be a good compromise between comfort and control. 

[c00nhunterjoe]

If i recall, 1"  bars are around 180 lb spring rate. And if you run any larger, they reccomend boxing the lower arms.

[moparnation74]

If i recall, 1"  bars are around 180 lb spring rate. And if you run any larger, they reccomend boxing the lower arms.

Great info.

[green69rt]

If i recall, 1"  bars are around 180 lb spring rate. And if you run any larger, they recommend boxing the lower arms.

Neat, I just got mine back from FF with the reinforcement plates installed and new bushings.  I would even use a 0.96 if it came down to it, but sounds like I'm good to go.  Thanks for the heads-up.

[PlainfieldCharger]

Here is an excellent writeup

http://arengineering.com/tech/torsion-bar-tango/

[HPP]

Check the Firm Feel web site or the Mopar Oval Track Modification books for listing of torsion bar sizes and corresponding  springs rates. FWIW, the spring rate and wheel rate are identical for Chrysler torsion bars as they are at the pivot point. There is no motion ratio to reduce their applied rates.

[green69rt]

Check the Firm Feel web site or the Mopar Oval Track Modification books for listing of torsion bar sizes and corresponding  springs rates. FWIW, the spring rate and wheel rate are identical for Chrysler torsion bars as they are at the pivot point. There is no motion ratio to reduce their applied rates.

Excellent info and also thanks to PlainfieldCharger for the link.   Sure are a lot of decisions to make when putting a suspension together!!

[PlainfieldCharger]

Thanks....just happened to be researching this at the time. I put in Mopar Performance ..96. Just took it for a ride this weekend. LOVE IT! Not to hard of a ride and went in very nicely..

[Mike DC]

  
I'm a fan of the 0.96" bars for the street too.  Just a subtle notch over stock, not much but enough to feel it.  



Keep in mind that the spring rate goes up dramatically as the bars get bigger.  

B-bodys originally came with 0.88-0.92" bars.  
A 1.00" bar is already about 1.5 times that stiff.  Big difference.  

[green69rt]

 
I'm a fan of the 0.96" bars for the street too.  Just a subtle notch over stock, not much but enough to feel it.  



Keep in mind that the spring rate goes up dramatically as the bars get bigger.  

B-bodys originally came with 0.88-0.92" bars.  
A 1.00" bar is already about 1.5 times that stiff.  Big difference.  

So, maybe the 1.00" is too stiff?   I've seen people go bigger and think it is ok.  I don't have anything to go by so just chose something bigger than stock (I thought stock was a little little mushy on my old RT, not much but a little.)

[green69rt]

I've been considering going with a stroked 400 CI engine which will reduce the front end weight.  That would allow a .96" bar but I couldn't find one.  FF has .94 and then 1.00.  That's kind of why I settled on 1.00, just in case I changed my mind and used a regular 440 block.

I should quit quoting bar diameter and talk wheel rates.  FF quotes the 0.94" bar as stock/HP at 142 WR and the 1.00 as 175 WR so it sounds like about 20% stiffer on the 1.00 bar which sounded about right for me.   

[PlainfieldCharger]

I went with the Mopar performance ones as they are the .96. I have a 440 in mine with some aluminum on it..still takes the curbs into the driveway nice and much less front end dive on braking.  I could see going with the FF 1.00 if I was planning on really driving it...if you know what I mean    Breaking things gets a little costly

[tan top]

 have mopar performance 1 inch bars on mine  , don't think they sell them now   

[HPP]

FWIW, Hotchkis is recommending 1.12 bars in support of their kits and this is what they are using currently in their Challenger. They are considering a drop in t-bar diameter and are evaluating some new s-bar configurations to work in concert with the smaller t-bar diameter.

As a point of comparison, BMW M series cars, which are typically regarded as very good handling set ups, are around 160-180 wheel rate up front.

I'm pretty sure MP bars have not been available for a few years now. There may be some stock at various dealers around the country, but when I was looking for 1.16 bars years ago, I couldn't find anything but 1.22.  Hotchkis, Firm Feel, PST, Just Suspension, and Bergman Autocraft are the best sources now days.

[green69rt]

Found 0.92 and 0.96 at Mancini racing and PST so still looks like 0.96 is available along with 1.00 from several others.

[PlainfieldCharger]

Summit has the .96  for 237.00 right now and the.92 for 329.00. Good price on the .96.....

[green69rt]

Summit has the .96  for 237.00 right now and the.92 for 329.00. Good price on the .96.....

That's better than $350 from PST!

[Brass]

I am happy with the 1" bars from Just Suspension.  (But no track time.)  They also came down in price at $199.99:

http://www.justsuspension.com/pro-touring-torsion-bars.html