Which torsion bar to use?

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Bill Crowell

Bill Crowell

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I have a '62 Valiant with a Mopar small-block V8 and 8" X 15" wheels that I don't intend to take to the strip at this time. I want it to handle the twisties instead. Should I use the .890, the .870 or the .810 torsion bars? Thanks a lot.
 
Bill Crowell said:
I have a '62 Valiant with a Mopar small-block V8 and 8" X 15" wheels that I don't intend to take to the strip at this time. I want it to handle the twisties instead. Should I use the .890, the .870 or the .810 torsion bars? Thanks a lot.
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It is generally accepted that be larger the torsion bar the stronger the spring rate will be better handling on road courses will be
 
Bill Crowell said:
I have a '62 Valiant with a Mopar small-block V8 and 8" X 15" wheels that I don't intend to take to the strip at this time. I want it to handle the twisties instead. Should I use the .890, the .870 or the .810 torsion bars? Thanks a lot.
Click to expand...

is this dedicated road course race car or street/road race?

I'd look at even going 1.03s if you're gonna race it alot
 
72Valiant4Door, I am not sure if I agree. If the spring rate is too high, the tire won't stay in contact with the road over irregularities as well as it would with a lower spring rate (it will display the "baby buggy" or "roller skate" effect). The Porsche is an example of a good-handling car with a relatively low spring rate. I think you want the maximum spring rate that will still allow the suspension to float a bit over bumps.
 
Bill Crowell said:
72Valiant4Door, I am not sure if I agree. If the spring rate is too high, the tire won't stay in contact with the road over irregularities as well as it would with a lower spring rate (it will display the "baby buggy" or "roller skate" effect). The Porsche is an example of a good-handling car with a relatively low spring rate. I think you want the maximum spring rate that will still allow the suspension to float a bit over bumps.
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well, to accurately figure the spring rate out, we need to know more. Plus the reason the porsche handles isn't just due to the spring rate; roll centers, instant center, Center of gravity all of those and more play a major factor into it. Most guys that run road courses and keep the T Bar suspensions run a .9 or larger bar, alot are in the 1.03 range, with some even bigger.

Are you going to run a sway bar? how big of one, solid or hollow, same questions for the rear. Also, what is your vehicle weight with you in it? how much horsepower? Stock height or lowered?
 
Shock absorbers 'decide'/control if the wheels stay in contact with the road.
Springs, along with anti-swaybars prevent overloading and excessive suspension (or car body) movements that unsettle the car/tires in corners and lose grip.

The .890, .870 and the .810 are still dragracing bars to me.
My Dart had 0.87 bars.
I upgraded to 1" and better shocks and can now handle corners that the car never could before.
 
I can only compare your car to mine;
The early As are considerably lighter than the 2nd gens. My 68 Barracuda does pretty good with the 1.03s, and 1.125 Sbar. Since I feel my car could use even more, I would be tempted to recommend them for you as well.Your 15x8s will allow more tire than my 14x7s, and that is key.
If you're buying new, I kinda recommend the 1.03s and sway bar, then adjustable shocks.
If you already have oem bars available, just put the fattest you got on there(minimum .89s), and buy a swaybar first.You will need the Sbar for sure, and this way you can get to know where the car needs improvement and get the right stuff on the first purchase.T-bars ain't cheap.
I think, if you can install the .89s cheap, the order of purchases should be Sbar, shocks, bigger Tbars.

Don't neglect the rear end; it needs to keep pace with what's going on up front.
Also, keep in mind that one steel wheel weighs about the same as 2 aluminums;size for size. Which is why I don't run steel.
 
Bill Crowell said:
72Valiant4Door, I am not sure if I agree. If the spring rate is too high, the tire won't stay in contact with the road over irregularities as well as it would with a lower spring rate (it will display the "baby buggy" or "roller skate" effect). The Porsche is an example of a good-handling car with a relatively low spring rate. I think you want the maximum spring rate that will still allow the suspension to float a bit over bumps.
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Do some more research on Mopars that handle. You'll see that most use large t bars. The Valiant I own is regarded as the most track capable stock type suspension A body in existence and it has 1.24" t bars.
 
Bill Crowell said:
72Valiant4Door, I am not sure if I agree. If the spring rate is too high, the tire won't stay in contact with the road over irregularities

YES, BUT WHAT DEGREE IRREGULARITY, AND TRUTHFULLY WHAT KIND OF AGGRESSIVE
DRIVING?
Porsche is an example of a good-handling car with a relatively low spring rate.
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Now you're comparing apples to Gucci loafers, and I guarantee the rear bars are not a
"relatively low" rate. Which Porch? There's plenty of variety there as well.

Seriously, nothing smaller than a .910 bars & a decent 1" stab. bar w/a V-8 in that car if
it's all there and all steel. I went .890's, but it's a six that's having a weight reduction/re-
distribution program. Your biggest challenge will be to find tires up to the task in 15"

This topic has been bludgeoned over and over, the above is a competent compromise
between street manners and cornering, and works well on real roads not tracks.
 
Killer6 said:
LMAO!!!!......oh wait, you were serious........ahem.
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I was giving my advice from hard research.

You want a larger spring rate for better handling... the thicker the torsion bar the better the handling

for road courses and turns you will obviously need additional upgrades to be able to compensate for the stiffer spring rate. Things such as sway bars bushings and shocks will be needed.

But the world record torsion bar handling are always set by a thicker torsion bar. You need better tires, you need better shocks, but for your original answer the thicker the torsion bar the better the handling.

I for example purchased 1.03 inch torsion bars which are the commonly accepted modern handling torsion bar but even on these I will be required to run a more modern shock and rebuilt suspension. I am not looking to run road courses for autocross I am simply looking to handle with modern safety.

If you look at pure science and the data of track numbers the stiffer the torsion bar the better the time on the road course comma this translates to a safer and better handling car on the street.
 
These cars have real wimpy bars from the factory. "Cloud soft".

It's well documented that somewhere between 1.00 and 1.12 is where you to be when Jesus shows up.

There will be no 'baby buggy' effect using a 1.03 bar and a small block. Ever. Use good shocks like the Bilstein RCD or Fox tuned.

Next, there are 0 sticky tire compound tires outside of a drag slick for a 15" wheel. Need to go 16"+ even then, select sizes, to take advantage of modern 'light years ahead of the 80's radial t/a' compounds used today; night and day difference.

All of this is a package, meant to work together; including your rear leaf spring rate which I hope you will consider and address as time goes on. 110-140in/lb seems to be the ball park that is played in.


PS: 72 valiant and the others are right on the money, as you will hear similar accounts as the thread progresses.
 
71DodgeDemon340 said:
id pick a torsion bar that wont roll off a work bench lol
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Xw1prYl.gif
 
Bare Minimum I say .920. But I'd go Atleast 1" if it were me. I have 1" in our dart with crappy kyb shocks and feel they are still too soft.

Don't be scared of the bigger bars.
 
Ha, ha, I guess I don't know too much, do I? Oh well, at least I'm willing to learn from you guys. Thanks for all your helpful replies. I deserved even the sarcastic ones! I'll measure what I've got installed now, and follow up sometime soon. Thanks again. I really appreciate the information.
 
72Valiant4Door said:
I was giving my advice from hard research.

You want a larger spring rate for better handling... the thicker the torsion bar the better the handling.

If you look at pure science and the data of track numbers the stiffer the torsion bar the better the time on the road course comma this translates to a safer and better handling car on the street
Click to expand...

1st good sir,I was addressing the OP and partial quoted him as well, I don't know where
You got the impression I was addressing You or Your post. And if You read my follow-up
post, I'm saying almost nothing contrary to your opinion, save for degree.
2nd, handling and cornering are not always the same, don't just interchange them. There
are cars that can corner on rails, but are a handful to drive/control, it is NOT always safer.
3rd, real roads rural,urban & other are far from most road courses in condition, stiffer is
not always better/safer on the street. I am not speaking to any particular setup as much
as I am a mindset. Oh, and the quote was ".810" bars".....which are not even OE
bars, but drag-only items not recommended even for reg. street use let alone carvin'.
 
Killer6 said:
1st good sir,I was addressing the OP and partial quoted him as well, I don't know where
You got the impression I was addressing You or Your post. And if You read my follow-up
post, I'm saying almost nothing contrary to your opinion, save for degree.
2nd, handling and cornering are not always the same, don't just interchange them. There
are cars that can corner on rails, but are a handful to drive/control, it is NOT always safer.
3rd, real roads rural,urban & other are far from most road courses in condition, stiffer is
not always better/safer on the street. I am not speaking to any particular setup as much
as I am a mindset. Oh, and the quote was ".810" bars".....which are not even OE
bars, but drag-only items not recommended even for reg. street use let alone carvin'.
Click to expand...

Sry for the confusion but i wasnt meaning to speak to or quote you. It will be okay, no need for such a defensive response, we are all here to help and learn.
 
72Valiant4Door said:
Sry for the confusion but i wasnt meaning to speak to or quote you. It will be okay, no need for such a defensive response, we are all here to help and learn.
Click to expand...

Lol,Ok, my chidingly sarcastic puzzlement at your post,in which you quoted me & then
seemed to address me defensively sounded defensive?:D My mistake, should've sprinkld
more emoticons in there. As far as the rest, I simply took the opportunity to clarify my own
stance on the subject,that is all.:)
As far as "research" goes, mine consisted of things like this. '72 /6 swinger 3200# loaded
w/fuel & myself, .870 t-bars, 1.125" frt bar, .75" rear bar, & 7 leaf stacks both sides. I then
proceeded to run down and practically run over almost anything I encountered in the nice
twisty-zones,incl. my then-neighbor & his 2yr. old IROC-Z w/VR skins. THAT is MY research.
Yes, those .870 bars should've been bigger, mainly for less dive under heavy braking &
occasional scraping on hard landings & dips. The car rode very comfortably, but was very
competent despite being soft, so I don't think .910 is "too soft" as your prob. not heavier
than I was.:glasses7:
 
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