i have regular base model sway bars on my 87 firebird right now. i have a set of 82z28 sway bars at my dads. my ques is... is it worth swaping the z28 sway bars into my firebird? will i feel a difference in cornering and stiffness? and are the z28's larger than the base model 87's

 

whats the size difference

 

'87 base model (V6 sport coupe) front sway bar should be a 34mm. I think the '82Z has a 32mm, but I also think the sway bar is solid. The 34mm will be hollow.

As to the rear, I think the '82z will have a 23mm rear sway bar, bigger than the 18mm rear bar of the V6 car. Definately swap rears!

You might want to add poly mounting bushings to your sway bars, too. Here's a message where I give part #s for the 34mm and 23mm bars: https://www.thirdgen.org/techbb2/sho...threadid=58782 I painted my 23mm rear bar with http://www.por15.com ; used the Super Starter Kit (semi-gloss) on it for $20. Came out great! Just don't apply the POR15 to the area for the mounting bushings. Cover that area with masking tape, and remove the tape when you're done painting the bar. As a side note, when I was painting the bar, I did it off the car. I used jackstands under the taped area to keep the bar "in the air" so I could paint it.

 

Oh; you can take an open-ended adjustable wrench, and tighten it down on the center of your sway bars. Measure the jaw gap with a metric ruler. Remember never to start at "zero" on the ruler, since that edge usually gets goofed up; try starting at 1cm for an accurate measurement.

You can also trace the wrench's jaws on a piece of paper. Then take the wrench and your ruler (or paper) to your dad's, and compare your bar's measurements with those of the 82's bars.

 

thanks for the help tomp. i plan on getting polyurathane bushings for the swaybars. for now im just gonna swap the rear sway bar out and put the 82z in.

 

also which front sway bar is better the 34mm hollow or the 32mm solid

 

32mm solid is more stiff

32mm solid front and 23mm solid rear should be a good combo for A V6 with out any added chassis braces (normal frame flex)

 

34mm hollow

 

My 34mm solid bar is more stiff than a factory hollow 36mm front swaybar. Just because the diameter is larger doesn't mean its stiffer. Also stiffer is not always better either. The front and rear bar need to be matched for weight bias.

 

Stiffer isn't always better. But don't forget the good amout of weight the hollow bar takes away from the solid, and the stiffness difference in the two is LESS than you might think.

Here's a rule of thumb for handling on street driven cars...

Bigger / stiffer swaybars will make a SOFT springed car ( like a stock V6 spring ) handle much better. Then the limiting factor is the tire and /or the driver.....

Stiffer springs will require LESS swaybar to acheive the same result.



HTH

 

the hollow bar is stronger than u would think i bet the solid bar would break easier than the hollow one. i have pix of my 36mm on my website

 

Ever see a solid barbell (weightlifting) break with all those weights attached at the ends? I didn't think so

Ever see a hollow tube bicycle frame crack?- many times

You might want to re-think your statement on a hollow steel tube being stronger than solid stock steel bar.

 

ok hmm lemme think they put the 36mm in the 1le but its weaker than a 32mm solid bar right!!.Thats why i changed mine to a 36 and noticed a difference.

 

Actually, I'm on an email list, and one of the members is a metal expert.....he does stress tests on different industrial products. He actually tested a hollow 36mm bar and a solid 34mm bar, and as far as torsional ( twist ) stiffness, the 36mm was stiffer by a fair amount.





FWIW

 

I'm not attacking your 36mm bar so don't get so defensive- I stated before you stated that stiffer is not always better- you must have missed that. Also, everyone always has a "friend who is an "expert"- Fact is that solid stock is much more durable and ressitant to fatigue than tube stock-That is a fact.

If what you claim is true that a hollow tube will hold up better in a stress test then coilsprings woud be made from tube stock and not solid to maintain their spring tension.

Spdfrk- I said 34 solid is more stiff than a 36 hollow, not 32 solid- learn to quote people properly. 36h is more stiff than a 32s, I never debated that- but after so many years of stress? who knows- it might not be then.

 

Wow. That was certainly enlightening.

Coil springs aren't a torsional spring, like a sway bar. The 2 shapes of metal and directions of forces applied to them do not compare.

Anyone familiar with suspensions would know that torsional strength of a sway bar increases approximately as the cube of the diameter.... there's a greater amount of metal (first power multiplier), it bends a smaller proportion of its total size (second power), and it's farther from the center so it has greater mechanical advantage (third power). So it turns out that the metal atoms near the outside surface of the sway bar are actually doing the lion's share of the work, so much so that it almost doesn't matter if the ones on the inside are there or not. But I guess some people don't really know how suspension parts work.

Supposedly, when new, the torsional stiffness of the 34mm solid and 36mm hollow bars were roughly similar; but of course the hollow bar is much lighter. Something these cars can certainly use, less weight on the nose. Like any spring, their actual measured stiffness changes with use, so who knows what you'd see if you measured them now.

It's certainly true that for optimum handling, you want a "match" of sway bar stiffness front to rear, in proportion to the car's "roll moment" at each end of the car. More is not always better. In general, if one of them is too stiff for the rest of the car's suspension, it will cause that end of the car to lose traction; so too much bar on the front will add oversteer, and too much on the rear will add understeer (loose). Alot of professionals get the best skid pad results by using surprisingly light ones on both ends of their cars. Watch cars on road-race courses, you'll usually see the inside wheel of whichever end of the car has too much sway bar, lifting in the turns. FWD cars are almost humorous about that; you'll see some of them lift the inside rear tire by half its diameter sometimes.

But I don't know anything at all about suspension parts, so don't pay any attention to me. I'm just shooting off my big keyboard.

 

LOL. Anyway, I am no expert but from what I have read other places I tend to agree with RB.

Ben