audioguru76

That is awesome! I'm gonna have to search around and see if they make one that is more suited for street use...if not i guess i'll just make my own.

fourthgenhatch

yeah it should work fine for the rear doing a strait through design, but on the front I want to upgrade to a larger sway bar and that would definitely have to be bent. so anyone know what the tempering process does

thanks

Tom-Guy

Mine for my '89 HF is a 15mm bar off a DB Pigtegra, shortened 1" right at the endlinks, plugged into the forwardmost two of the three rear towhook holes. Requires mild massaging of the Integra swaybar mount brackets on top of the swaybar itself being cut/welded.

Yup. You get the same torsional rigidity with a solid bar as you do with a hollow bar, or close enough after a certain point. That's why stock Honduh bars are hollow bars.

gsrcrxsi

yup, most of the torsional rigidity (thats the word i was looking for, been a year since my mechanics class lol) is on the very outermost part of the bar anyway.

^just in case anyone wondered why a thin walled tube can be the same rigidity but with less weight

bumblezc

Really Honda Bars are hollow. Didn't know that.

But ya, Statics and Dynamics 101, In a Torsional Shear Stress application such as a sway bar, Tube wall thickness is not an issue.
Example of Torsional Shear Stress. The length of the Verticle line Represent the magnitude of the Tortion Shear Stess. Notice how the further you are from the center, the bigger they are.

gsrcrxsi

fixed it for ya

bumblezc

Na, Lazy and using Auto Trim in AutoCAD. Thanks

mugenblacky16

First of all, it's not dynamics because swaybars are fighting a bending moment and torsion and the sum of all those forces is zero. Second, what do you mean, "wall thickness is not an issue"? Of course it's an issue. Your graph is just a picture of the shear load distribution. It doesn't mean ----! Torsion applied to a tube is calculated different to factor that the tube has much less cross sectional area, not to mention that tau average is way out at the mean radius. A solid bar with a torsion applied has a bigger cross section. For example, to find the max shear stress(tau) in a solid shaft you would simple find the polar moment of
inertia( J=pi/2(r)4 ) and calculate to torsion formula (Jmax = Tc/J ). Tau max units are given in force/size; i.e. lb.ft. Tubular torsion uses the same torsion formula, but J will = pi/2(ro4 - ri4), which gives you the cross sectional area of the tubing wall.

The tubing used doesn’t need to be tempered. Without getting too involved use same dynamic equations to figure out how much force the bodyroll will have in a given turn on at a given speed minus the pressure of the force of the spring(stiffer springs will lessen the force on the swaybars). You’re trying to find how much force is lifting up on the car’s inside(side on the inside of the corner) suspension. Take that force(sigma or n) and times it by the distance from the point the swaybar and control arm link to the point where the sway is parallel with the firewall(heading to the other side) (d ). Measure 90° back. This will give you your bending moment and torsion back at where the swaybar heads to the other side.

Calculated sigma max of your tubes bending moment and cross check that the tension and compression are this in the elastic region of the material you are using (modules tables for specific materials can be found on the web or in the back of your statics and mechanics books). Next, cross check that the torsion does not exceed the elastic zone. If you forces are so great that they enter the yielding or even the strain hardening zone then the stress on the bar is too much and the swaybar will permanently deform. Bigger, thicker, stronger(material used) will give you a higher moment of inertia and handle more torque(from bodyroll forces). Just like everything you have to do you homework to do it right. Homemade swaybars are definitely possible and would probably work well, but expensive namebrand bars are expensive for a reason. They give you functional performance in a perfect balance. If you don’t want to do all the math I would try and copy the specs of a namebrand bar and find a material that has the same or as close to the same elastic region on the stress-strain diagram.

fourthgenhatch

wow, nice reply. I didn't know all of this. Can't wait to start taking these Mech Eng classes over at Georgia tech in a couple years, chem and calc are pretty boring, can't wait for physics and higher level. I'm a dork

shogun

i know im a noob, but here is my two cents, i used a 4340 steel bar for mine, just machined it first then i bended it and slaped it in, im runing slalom ties as close as some racecars in a tercel 4wd weighing 3400 punds