What torsion bars to use?

[Propwash]

Here's the dilemma guys...........

I have a 69' Roadrunner that came with a 383, but will soon have a 512.

I have 3 sets of torsion bars:

-Original set of factory bars
-Brand new set of Just suspension 1.000'' pro touring bars
-donated set of PST 1.003'' bars

I was hoping to upgrade up front to a little better performance. The rear has new Mopar XHD springs and a Cal Trac system. Up front is original style besides a disc brake conversion and Hotchkis adjustable strut bars... Shocks are KYB in the front, Edelbrock IAS in the rear.

The car will be spending about 80% of the time on the street, 20% at the track...

Do I go all out with the 1.003" bars or is that going to make the ride like a hay wagon and just go with the 1.000"?

Any advice is much appreciated..

 

[5.7 hemi]

If you want to get rid of the set you dont use, I'll take them off your hands. If it was me, I'd use the 1.003 bars. They will handle alot better for the street and since the car will spend most of it's time there, might as well use the better of the 3 sets.

 

[Propwash]

That's what I was thinking as well.. I have seen folks chatting here and there about too stiff of a spring that gives a poor ride comfort wise and problems at the strip. Just wondering where the line is drawn on that as far as size. Hotchkis bars are 1.003" as well and is advertised as their ultimate upgrade for handling performance..

As far as getting rid of a set I don't use...you bet! I sure don't need any more spare parts laying around here. Starting to turn into a jungle gym..

 

[70Hemi]

I put the hemi in my '70 383 rr back in 1990 and just used the stock 383 torsion bars. drove it about 20,000 miles before i tubbed it and it drove just fine. glad to hear you upgraded to front disc brakes. the extra weight of that hemi sure made the front drum brakes seem worthless. good luck

 

[darkhorse]

I agree with the bigger T- bar ie for majority of street use ....im interested to know how you think about the adjustable strut rod and why you went with them over non-adjustable?Ive done afew f/e and never used them just curious to advantages

 

[Cranky]

Why would .003 make much difference? Are they 1.030 and not 1.003? With the CT's, I'd go with the stock 383 bars but if it were mine it would get a set of 318 bars if you're wanting performance on the track....and if you didn't like the handling on the street, you can always swap them out.

 

[5.7 hemi]

I'm sure of the calculations, but that tinybit of difference equates to a much higher spring rate 1.00 vs. 1.003. AR Engineering has a really good explanation of torsion bars and the rates and how to calculate them.

Propwash, just let me know thru pm of what ya wanna do.

 

[Cranky]

I'm sure of the calculations, but that tinybit of difference equates to a much higher spring rate 1.00 vs. 1.003. AR Engineering has a really good explanation of torsion bars and the rates and how to calculate them.

Propwash, just let me know thru pm of what ya wanna do.

I know .003 can make a difference but just don't see it making a difference that you could feel. I mean, that's less than 3 xxxx hairs lol

 

[5.7 hemi]

Yeah, I didn't figure it was any real difference til I read that article and found a few others to back it up. I couldn't think of anything funny to go with the "hairs" comment so I'll leave it alone, lol..

 

[Cranky]

Yeah, I didn't figure it was any real difference til I read that article and found a few others to back it up. I couldn't think of anything funny to go with the "hairs" comment so I'll leave it alone, lol..

:hello2::headbang:

 

[AZRC]

I would not think .003 would make a difference either. I would think the metal that is used and how they formed the torsion bars would make more difference.

 

[Propwash]

Thanks for the imput guys......

Plan for now is to leave the large bars in till I get a chance to try them out. If i'm not happy with it, I start stepping down in size.

Thanks again

 

[Cranky]

I would not think .003 would make a difference either. I would think the metal that is used and how they formed the torsion bars would make more difference.

How many different ways are torsion bars made?

 

[5.7 hemi]

They should be forged.

 

[Meep-Meep]

I was thinking the same thing as Cranky - .003" is almost nothing. But I looked up some facts and the stiffness of a bar is a cube function. There is also a difference between a solid bar and a tube, but still, .003"??

 

[Cranky]

They should be forged.

I know how coils are made but never gave torsion bars much thought...go figure...

 

[shag766]

i am in the same boat prop, pardon the pun, boat prop. i have the original small block bars in the 69 440 and they look spotless. ordered a new set of hemi bars, still in the box. after much reading and asking ?. i have been led to believe that the smaller bars are good for the strip and i don't plan on a lot of high mileage driving.
so i am going to try the smaller bars and if i don't like the feel i will go bigger bars. same as you, 20% track and 80% road. rick

 

[darkhorse]

Ive always heard of using the smaller bars as well for the strip . I believe it has to do with weight transfer.

 

[Ron 73]

Here's the dilemma guys...........

I have a 69' Roadrunner that came with a 383, but will soon have a 512.

I have 3 sets of torsion bars:

-Original set of factory bars
-Brand new set of Just suspension 1.000'' pro touring bars
-donated set of PST 1.003'' bars

I was hoping to upgrade up front to a little better performance. The rear has new Mopar XHD springs and a Cal Trac system. Up front is original style besides a disc brake conversion and Hotchkis adjustable strut bars... Shocks are KYB in the front, Edelbrock IAS in the rear.

The car will be spending about 80% of the time on the street, 20% at the track...

Do I go all out with the 1.003" bars or is that going to make the ride like a hay wagon and just go with the 1.000"?

Any advice is much appreciated..

JMO.. I really think think the original if in good shape would be worth having, never had mine on the strip but 1/4 mile of racing it did do i thought it was great. Street racing that is...
'

 

[Cranky]

Ive always heard of using the smaller bars as well for the strip . I believe it has to do with weight transfer.

It depends on the weight of the car and the power it has too. for instance, I had a mid 10 second Road Runner and it would left the fronts off the ground a good foot+ but didn't have the power to keep em up and it would land kinda quickly and then unload the rears. After doing numerous adjustments, I put it all back to the way it was and stuck on different front shocks. It slowed the lift rate but would still lift the tires but only a few inches but it quick unloading the rears. It had slant 6 bars.....and just unwound too quickly.