another Torsion bar thread - updated - adjuster and bolt?

[timmycharger]

Didn't want to hijack the existing thread about 318 to 440 torsion bars so I started this one.  I am looking to replace my bars which I should have done when I had the car apart but at the time it didn't seem important to me.  My car is originally a 318 car and still has the original 50+ yrs old bars in there. They were fine when I had my car setup for the strip, with drag shocks etc but now I want better handling.  I am not interested in autocross or anything like that, just want it safer on the highway.   Never shopped T bars before, but I know I want something improved over stock.

Right now, I have an aftermarket front anti sway bar mounted, frame connectors welded in, and just parts store shocks with ESPO springs in the back slightly higher than stock.

Is the below a good option or should I be looking into suspension specialty companies like Hotchkiss etc?

Appreciate any feedback. Thanks guys

https://www.manciniracing.com/mop960diambe.html

[green69rt]

If you click on the "spec sheet" on that TB, it gives you a discussion of torsion bar design.  At the end of the discussion it references Firm Feel as a vendor that does it right.  That's who I bought mine from at 1.0"   As you indicated, the discussion is all over the map as to what is right.  Your choice at 0.96 will probably be a big change in stiffness and control.  Only you can decide what is right for you but I would say you are on the right track.   You could probably go thicker since you have already added frame connectors and sway bar but better shocks would work better with the bigger TBs.

The ones I used are on this page and 1.0 inch.

http://www.firmfeel.com/b_body_mopar_torsion_bars.html

[timmycharger]

If you click on the "spec sheet" on that TB, it gives you a discussion of torsion bar design.  At the end of the discussion it references Firm Feel as a vendor that does it right.  That's who I bought mine from at 1.0"   As you indicated, the discussion is all over the map as to what is right.  Your choice at 0.96 will probably be a big change in stiffness and control.  Only you can decide what is right for you but I would say you are on the right track.   You could probably go thicker since you have already added frame connectors and sway bar but better shocks would work better with the bigger TBs.

The ones I used are on this page and 1.0 inch.

http://www.firmfeel.com/b_body_mopar_torsion_bars.html

Thank you! didn't even notice that spec sheet!! Appreciate that link as well, I have the FF state 2 steering box already, great piece!

[Mike DC]

Years ago I switched a 318 car from 0.90(stock) to 0.96 bars.  It was a slight difference but not a lot.  I was happy with them, but I do like my corner springs on the soft side compared to some guys.    (I don't like them drag-race soft, just a little soft for a sporty car.)

1.00 is a bigger difference but I wouldn't suggest going higher than that.  Modern chassis theory is to keep the corner springs on the softer side and get more stiffness from the sway bars (that, and use smart shocks).  

The same thinking says DON'T stiffen up the rear leaf springs in a big way.  Even the stock "6 leaf" (staggered) R/T springs are arguably too stiff by the time you add any size of rear sway bar.  IIRC the XV Motorsports crew settled on 5-leaf rear springs for their stage-1 handling package.

[b5blue]

  I put R/T size T-Bars and springs on my 70 from Mopar and added an ADDCO rear sway bar. (That had a vintage Mopar Performance cross reference.) The car rides and handles nice for a daily driver. My car is peppered with Mopar Performance parts, CH4B intake, 145K T convertor, Road Runner cam W H.D rockers, Timing chain and gears, I use M.P. anytime I can. Monromatic shocks were so cheap on Rockauto I threw 4 on to test and like them.

[c00nhunterjoe]

If you read through that other thread, i put the basic formulas for calculating required wheel rates. For a spirited driver that wants to corner on the street, the 1.0- 1.06 are the general fit depending on your front axle weight. Roll her over a scale and see what she weighs. The .960s, while a huge step up over a small block .880, will leave you wanting more. If you go over 1.0, box the lower arms and reinforce the torsion bar mount in the frame.

[timmycharger]

THanks for the replies and feedback guys, much appreciated. I was leaning towards the Mopar Performance bars I put a link to but I wasn't aware that Firm Feel had the 1.0 ones that Mitch and Joe noted.

Yes, I did check out your posts in the other thread, lots of stuff to digest but overall great information. The plan was to take it to the strip this Spring and put it on the scales but now that isn't happening as I'm sure the track will be closed for a while. Last time I weighed it was in 2001 when I had the 440 with iron heads, a 727 auto and 8.750 rear, manual steering, glass hood and aluminum wheels, it was 3680 lbs..  

Since that time, I changed to Aluminum heads, but put the steel hood back on, steel wheels, power steering, power brakes, A/C, Hemi 4 speed, Lakewood bellhousing and a Strange 60 rear... So she should be about 6000lbs by now LOL..

[Mike DC]

Since that time, I changed to Aluminum heads, but put the steel hood back on, steel wheels, power steering, power brakes, A/C, Hemi 4 speed, Lakewood bellhousing and a Strange 60 rear... So she should be about 6000lbs by now LOL..

I'm guessing 3900-4000. 

[timmycharger]

I ended up getting a set of PST 1 inch bars and before I start taking the car apart I am curious if I will need a new set of torsion bar adjuster bolts or not.

I read somewhere that I could be in a situation with the bolts being long and possibly hanging down lower with the bigger bar? This is new to me so figured I'd ask. Thanks!

[375instroke]

I have the Firm Feel 1.03" bars, and with the adjuster almost all the way up, the car is still low.  At some point, the aftermarket bars are either indexed or not, to compensate for them not twisting as much as the lower rate stock bars.  I may not have installed the bars properly, like maybe I was supposed to install them with the control arm hanging down more, before the lower ball joint was installed.  Some day I may try that, but it sits where I like it now.

[justcruisin]

I installed the PST 1.03" bars, with about 1" of clearance to the bump stops the adjuster is about 1/2 way. The bars I have have a 20 degree clocking. I think their older bars weren't clocked.

[Kern Dog]

The same thinking says DON'T stiffen up the rear leaf springs in a big way.  Even the stock "6 leaf" (staggered) R/T springs are arguably too stiff by the time you add any size of rear sway bar.  IIRC the XV Motorsports crew settled on 5-leaf rear springs for their stage-1 handling package.

Great point.
When I first built the red car, I was coming off of owning a '76 Camaro that I set up to handle well. In theory, many of the same principles apply but there are variables.
I just assumed that a rear sway bar would be needed with the Charger. The Mopar is a little heavier than the Camaro was.
I initially went with 1.0 t bars, a 1.25 front sway bar and the MP XD leaf springs and a 7/8" Addco sway bar. The car was neutral at low speeds but wanted to hang the tail out as speeds increased. Over time, I increased the front spring rate and reduced the rear to achieve a much better and more predictable car.

[Mike DC]

   

Great point.
When I first built the red car, I was coming off of owning a '76 Camaro that I set up to handle well. In theory, many of the same principles apply but there are variables.
I just assumed that a rear sway bar would be needed with the Charger. The Mopar is a little heavier than the Camaro was.
I initially went with 1.0 t bars, a 1.25 front sway bar and the MP XD leaf springs and a 7/8" Addco sway bar. The car was neutral at low speeds but wanted to hang the tail out as speeds increased. Over time, I increased the front spring rate and reduced the rear to achieve a much better and more predictable car.

Yeah, that's what happens when there's a ton of stiffness in the rear.  The car seems neutral when you aren't pushing it that hard but the tail starts wagging when you get on it.


These cars seem to need either the R/T leaf springs or a rear sway bar, but not both. 

With leaf springs, we are sorta caught between the ideal starting line (drag) setup vs the ideal handling setup.  Drag launches want a stiffer leaf pack than handling/ride does. 

[Kern Dog]

I don't care about drag racing. I like cars that handle and stop well.
In many cases, a car that handles well is  competent at drag racing BUT a dedicated drag race car does not handle very well.
When I was sorting out my setup, I tried running without a rear bar. The car immediately felt safer during rapid turning movements but the body roll increased more than I liked.
That Addco 7/8 bar had urethane bushings. I tried running rubber end links to give up a little of the "edge". It wasn't enough.
I tried a 3/4" bar with longer arms , frame hung instead of axle mounted. I never calculated the rate but to me, 1/8" smaller with arms about 1 1/2" longer should have been a noticeable difference. It was/is. I didn't want to soften the leaf spring rate because I get tire rub already and didn't want even more of that.

[c00nhunterjoe]

Fwiw, i still run the oe springs on my car and have in each state of its use from corner hugging with 275s on all corners to drag racing in its current form. The rt springs are a good choice for a street car that does a little bit of everything. Mine is stiff, but comfortable in the rear, does not sag when i have 3 people in the back, hugs corners if i put wide tires on the front, and also cuts 1.4 60' times on slicks with ease. Only change i made to the origonal leaf packs are a pair of clamps to prevent excessive separation at the track on launch. Im sure kern's will outcorner me as his is more corner driven built, but i can make it back up in the straightaways. Lol. There are many forms of "dedicated" drag cars. Many are required to use stock parts, and run 8 second 1/4 mile times on skinny tires. Quite impressive considering. They are very street friendly and several local to me are actually daily drivers with ac. Not every dedicated drag car is tubbed with a 4 link and unable to corner. Thats 1970s thinking.

[Kern Dog]

Yeah, that makes sense too.
I grew up in the 70s and 80s when the guys that were into drag racing used slant six torsion bars, 90/10 front shocks and pizza cutter front tires! 

[c00nhunterjoe]

I run a 205 on the front of mine currently as the vector wheels are 7" wide. If i could get a narrower wheel, i would run a skinnier front tire at the track. We've been over my torsion bars. Nothing fancy, stock rt diameters. I tried the skinny bars and they are horrible at the track and on the street.