1-1/8 & 1-1/4 front sway bar vs factory 7/8?

71DodgeDemon340 said
So im having a hard time understanding, i found a sway bar spring rate calculator and assuming all lengths are the same, a 1-1/8 solid bar will be 1.75 times stiffer than a 7/8 solid bar. And the 1-1/4 tubular bar at .25” wall thickness (guess) will only be 1.5 times stiffer. Is this true? But then i saw a video where a 1-3/8 hollow bar had more stiffness than a 1-1/4 solid bar.

From hotchkis: “a 1’3/8″ hollow bar is equivalent to a 1’1/4″ solid. But the 1’3/8″ hollow bar is 6% stiffer and 43% lighter than the 1’1/4″ solid.” So a 1-1/4 hollow would be equivalent to a 1-1/8 solid but be slightly stiffer and lighter?

Im about to just go the solid 1-1/8 bar route and say screw it lol

Not even sure how accurate the calculator is

I appreciate everyones input and thanks for being patient with my questions.

Also according to summit the hellwig 1-1/8 tubular bar is curently discontinued and the 1-1/4 tubular bar is being discontinued with none in stock, the 1-1/8 bar is available, so are they limiting it down to only one option on the front? Im just concerned about it being too stiff if its even possible with .870 bars

@72bluNblu
@autoxcuda

Calculating the stiffness of the bar depends a lot on the wall thickness, so guessing for the wall thickness won't give you a very accurate answer unless you're right on. The other thing is that most of the calculators assume that the metal all has the same spring constant, which isn't necessarily true either. And the exact shape of the bar plays a role too, so even similar diameter bars can be slightly different. They're not a bad way to get a ballpark estimate, but to get an accurate answer you need to have the actual specs.

Or just believe Hotchkis. My guess would be that the 1 1/8" solid and 1 1/4" hollow bars are pretty close to the same for stiffness with the weight being the biggest difference.

More than likely though you won't be able to tell the difference in stiffness or weight between those bars, because both are going to be relatively small differences. And with your torsion bar and tire compound options your car isn't exactly optimized to the point that a small difference would really stand out. You're talking about a margin that might show up only if you're running consistently against a stopwatch, not something you'll feel by the seat of your pants.