Torsion Bars: Help Me Pick The Right Size

[Road_Runner]

I'm trying to decide what diameter is the right size for my 73 small block Barracuda.   I think I'm going to go with Mopar Performance XHD 6 leaf big block rear springs.  I was thinking about the .96 bars but don't want to make the ride too harsh.  I've got a set of original front & rear sway bars to go on it, but I may opt for a slightly larger front sway bar if I really need it.  I also have a set of lightly used Edelbrock shocks to go on the car as well.  So for this mix of parts, what is the right size torsion bars to use?  Are the stock bars too small to match with ther rear springs, etc.?  I'm not looking for track car performance, just more solid predictable handling.  Any suggestions or advice would be greatly appreciated, especially if you're familiar with this setup and can comment on what the ride will be like.  I don't want it to be too harsh as it rides super nice right now just not that confidence inspiring when you need it to be.

Thanks in advance, Jim

[tommyg29]

all I can tell you is I have .96 bars in my 440 bb 4000 lb car, and it is too stiff for everyday driving imo.
Maybe good for road course or strip, but not comfortable on the street.
If you have to deal much with potholes or speedbumps, you definitely will want something much smaller with a small block.

[brads70]

all I can tell you is I have .96 bars in my 440 bb 4000 lb car, and it is too stiff for everyday driving imo.
Maybe good for road course or strip, but not comfortable on the street.
If you have to deal much with potholes or speedbumps, you definitely will want something much smaller with a small block.

 LOL not to  but I have 1" T-bars with a 440/727 and cheap jobber shocks and I found the ride OK? Id like to try 1.040" or 1.060" bars if I had the budget? I'm no expert but other whom I respect their opinions say it's all in the shocks with bigger bars?
Over the winter I'm installing Hotchkis sway bars, upper A-arms and RCD Bilstein shocks so I expect the ride to be "softer" not that I found it harsh at all?
With a cast iron headed small block.... I'd try 1" bars? IMO?

[cudazappa]

My combo is 1" bars, stock-ish shocks, 1 1/8 front sway, stock leaves, and 17" wheels.  And a small block.

Rides like a modern car, but needs better shocks and/or 15" tires and 60 series rubber.  Notice pot holes with this combo, but rides very good.  The ultimate critic, my girlfriend, who rides shotgun, had not one bad thing to say about it the 300+ miles to and from Carlisle.

I think you'll be fine as long as you use the eddy shocks.  There are some good reviews for them from people who've used them.

[tommyg29]

Ive got the eddy shocks too, and maybe I'll trade you my .96s for some smaller bars.
I'm guessing every car is different. My car is about as heavy a cuda as you will find anywhere.
Iron everything, every option and even an iron scattershield.

[tommyg29]

on second thought, maybe partly because I have 245/45 rubber up front?
But, remember the big block original size was .92", and I assume the small block was smaller.
Some people find 1" or bigger just fine, while others think .92" is too stiff.
I guess it depends on your setup and preference.

[72bluNblu]

Well, I'll throw in my  . 

I think just about everyone knows I run 1.12" torsion bars in my 318/904 Challenger. I run tubular upper and lower control arms and polyurethane bushings. I currently run 235/60, 245/60 rubber, no sway bars (yet, although that doesn't change the "ride" much, just the handling), and KYB gas adjust shocks (soon to be replaced). And I still don't think my car rides too stiff. Which is why, hopefully in the NEAR future, I'll have 17" rims and probably 275/40 tires and shocks that will keep up with my bars.

Now, I wouldn't recommend going that big with the torsion bars, for a street/cruise car it really isn't necessary, and can cause some ride height complications. But I think you'd be fine with a .96 or even a 1" bar. Just Suspension is selling their 1" torsion bars for $199 at the moment, saves about $100 over most places.

1" bars (or .96's) are a good match to the XHD's. As far as the sway bars, the stock sway bars paired with 1" torsion bars and XHD's should make for a pretty decent handling car. You could still improve the handling with larger sway bars, but again, for a street car they should work pretty well. Shocks are an important deal too. The KYB's I have are fairly stiff, but they still aren't enough for the bars I run. Edelbrocks are ok too, but you might look into the Bilsteins Hotchkis sells. At $400 for a set they're a really awesome shock at a good price. For your car, I would put my money into shocks before I upgraded the sway bars.

So, what I would do is- 1" torsion bars, XHD rears, stay with the stock sway bars, and consider the Hotchkis shocks. The end result should be pretty solid handling car that should still be comfortable to drive. The "ride" will definitely be more modern, but I don't think it will be anything approaching teeth jarring or kidney bruising. But I may have a high tolerance for that sort of thing.

[Strawdawg]

X2

I think the only danger is when running very low profile tires on rough road surfaces. 

I am a strong proponent of Bilstein shocks having been using them since the '80s.  My experience is that they are superior to the Edelbrocks (altho I have only used them once) and much superior to the KYB's when it comes to ride control.

I would think the 0.96" would be great for a handling small block with reasonable tires....

[HP2]

Ride quality can be a very diverse subject as they are any number of factors that can influence and we all have very different perceptions of what consistutes that quality. Horsepower is easy to quantify, even handling has numbers to compare, but ride quality is a tougher nut to crack.

Food for thought; XV Level 1 kits runs t bars that are easily in the 1.12 range, yet they produce a very comfortable ride that is firm, but not jarring. The secret to their ability to do this, even with the low profile 40 series tires they recommend, is having shocks built to specifically match the frequency rates of their t-bars. Shocks are an often overlooked performance and safety feature and scrimping here will only produce less than optimal results. I would say that a single adjustable or a high end fixed valving shock like Koni or Bilstein will net huge dividends no matter what size bars you run and you should probably allocate a higher % of budget to shocks than trick sway bars or control arms.

I'll second the recommendation by 72bluNblu as a pretty hot street crusier set up.

[tommyg29]

I know this may be the subject for or from another thread, but the overall (front AND rear) suspension components figure in to ride comfort, and not just the front torsion bars.

[cudazappa]

I'm just going to reitterate what HP2 said, Quality Shocks are a MUST.  They can make or break "comfort"

I also agree with 72bluNblu, that's a pretty solid setup, and very close to what I had last year.  It handles like a modern car.  I'd equate it to my GF's 03 Honda Accord.

The snow is melting though so I'm getting antsy to start swapping in my 1.22" torsion bars, order some 225# monoleafs for the back, and Hotchkis Bilsteins and start tearing up the track.

[Road_Runner]

Great feedback guys, and I think I will go with the .96 T bars but will think about the 1".  Sounds like I'm OK with the stock sway bars and at least for now I'm going to at least try the Edelbrocks since I already have them unless I decide to put them on the Roadrunner instead. One more thing I probably should have mentioned is the wheels & tires I'm running: 15x7 front & 15x8 rear rallyes with BFG TA Radial 245/60 on front & 275/60 rears.  So I definitely will get some cushioning out of these tires which sounds like a good thing with the stiffer torsion bars & springs I'm looking to add.

Thanks again, Jim

[HP2]

I modeled two different set ups for my car; 1) .96 t-bar, 1.125 front s-bar, 120# rear leafs, no rear s-bar and 2) 1.22 t-bars, 1.125 front s-bar, 120# leafs, and 1" under axle rear s-bar. Both produce the same amount of roll couple for the weight bias in my car, but should feel quite a bit different in ride and performance. Since I'm hoping to hit an autocross or two this summer, I went with big bar route. I've also gone with Varishock single adjustable shocks to allow me to tune in the shock motion. Swapping set ups would be pretty easy for me to do if I really dislike the combo, but I think it will work out nicely.

Jim, your set up will nuts on for a street car. You'll be really be impressed with it.

[Strawdawg]

The only thing I see that I don't like are the BFG TA tires...I have found them to lack "feel" and directionality.  As other threads have discussed, we don't have many choices in a 15" when it comes to street tires these days, tho.

After consideration, I think I am going to a 17" wheel with Nitto 555's.  I need to buy wheels because the car I am working on currently has 14's on it.   Other than drag radials, I don't have any other Nitto experience, but, they have to be a lot better than the TA's.    that is my experience, anyway.

I just finished putting Hotchkis rear springs on and and back on the front end installing 1.03" bars, struts, etc. along with the Hotchkis bars on both ends....this is on a 318 suspensioned car that someone put a 440 in.  Except for price, I might have gone with 1.12" bars....

[Road_Runner]

Thanks HP2  & I don't dsagree about the BFG's Strawdog, but as you say for 15" there's not a lot of choices.  I might consider 17" wheels at some point but I really like the look of the rallyes and I get a lot of compliments about how original the car looks which is also what I'm going for looks-wise.  I'm trying to resist the urge that more is better with this car leaving the extremes for the Roadrunner.  So nice solid performance & handling is what I'm going for & hopefully I can stay the course!

Later, Jim