Which are better?

The biggest advantage to Hollow bars is they weigh less.

I have Strano's 35/22 hollow set and couldn't be happier.

For the street or straight line a hollow design is fine and yes they are lighter but they are not nearly as strong as a solid bar (YET). In order to make a hollow bar as stong as a solid one you need to use very very STIFF material and this takes away some of the torsional flexability of a sway bar. (and usually means a big increase in diameter) Too stiff of a material and the bar will react too violently and can cause the tires to lose traction, The flexability of the less stiff material solid bar will make for a smooth body transition with out needing major inputs from the driver. In most autocross applications a solid bar is preffered because it allows for more strength and a better body transision meaning more traction to the cround in the corners, but yes this does mean at a weight penalty.

Some high end spring and sway bar manufacturers only rate thier sway bars by rate increase because this helps you choose a bar for your specific chasis.

A sway bars diameter can also only tell you how much material is used and alot of people think that just because a bar is thicker it must be stronger but it is the material used and bend points that dictate how a sway bar reacts. This means that not all 32MM bars for instance are created equal just because they are for the same application.

John Heinracy was the original design engineer for GM on the original late 80's 1LE cars and he was involved in a build of a 2002 WS6 and I couldn't find out the front bars design or specs they just called it a Custom front stabilizer bar. I am thinking of goign to a 35mm bar from my 32mm bar in front. My car does already handle like it is on rails and if I hurt the handling by going too stiff the 32mm can go back in but I bet the 35mm will just compliment my other mods better than the 32mm 1LE bar does.

Oh a link to the WS6 John Heinracy was involved in here is a link:

http://www.highperformancepontiac.com/feat...tion/index.html

So for the street I would and do go with a hollow bar myself (in front) because you can get a good bar that has the flexability needed to keep the taction planted and it will be a great deal lighter than a solid bar.

GM's famous 1LE suspension has been offered in many forms over the years but if you look at the 4th gens the early 4th gens had a 32MM bar and the late 200 and up I think had 35MM front bars both hollow but GM knew they wanted weight to stay down and still get great strength. They could have gone with a solid bar in front and had more strength but in todays cars with power to weight ratio being so important they chose (wisely) to stay with a hollow bar and just increased it's diameter and build specs. (the I.D. is smaller than older bars and the wall thickness has increased.


Autocross once in a while and I would use a soild bar. You also get into bars that are adjustable and not adjustable but unless you are autocrossing everyweekend and tweaking to cut every tenth off of your times I would go with the much simpler non adjustable solid bar.

Technology in metelergy has come a long long way also and today they can make hollow bars that are prety much as strong as a solid bar you can get into cryo (cryogenics) when you heat up a part first then super cool them to pack all the molecules together to produce a much stonger part. As technology and materials as well as manufacturing techniques get better light hollow bars will be the only way to go and solid bars will be only used on crazy power drag cars.

Have Fun
Doug

Wow thanks for all that. That was really helpful. Ya i am thinkin i might get into autocrossing once i get a few more suspension uprades. But not every weekend.

A couple of friends of mine have the Hotchkis but the one speaks highly or the strano parts.

So pretty much my car will be street and the occasional autocrossing(maybe more if i really get into it).

You think the Strano Sway Bars front and rear would be good? Or should i go like Strano 35mm front hollow and Spohn 25mm rear solid?

Send me your regular email address and I'll send you a paper that I co-wrote for the Porsche Club on this very subject. What you are discussing is a bit more complex than the answers received, but the answers given so far are essentially correct. The paper won't tell you what sizes of sway bars to use--that's up to you, but it will tell you what the different suspension parts will do for you in whatever part of the corner you need to work on.

One important consideration is that if you choose a swaybar that is too strong, it will actually start to twist the front end, or bend suspension parts, it could even overpower springs and shocks. Of course those parts bend right back, but it does diminish the swaybar's effectiveness. In other words, be careful about going too strong.

Don't forget to use negative camber on the front end with any good swaybar. For autocrossing maybe one degree or a little more; for the street, anything from 1/2 to 1.0 degree negative will do wonders for the handling and you won't need as much in the swaybar department, it will even make the tires wear better. Again, everyone tunes their cars to their needs and whether or not they like the way it feels to them. All I can say is evaluate what the others have posted, if you like it, do it and then you become the expert.

Yup, as I stated and Me Too agreed with if you over bar (go too rigid you can hurt handling alot).

The bars you mentioned are very good bars and are both used by tons of people so you would have good luck with both. But I agree you have to decide what you want and try them and see if you like it.

The Strano 35 hollow front and spohn 25mm solid rear would be a killer set up in my estimate.

what I suggest is riding in and driving as many different set ups as you can before you purchase something.

The suspensions in the 4th gens are all similiar with just different spring rates and diameter bars so you could go with the latest and greatest for the 4th gens the 2002 1LE and it would be awesome! it is esentially designed for your car by GM.

in 1993 they didn't have the manufacturing techniques that they do now and you can get great bars with real good memory and very long lasting dependability.

So again, go ride in various setups and see what you like then buy them.

Doug

Ok, on this hollow bar vs solid bar discussion. Let's get to some facts on this, but not too many facts..... If a solid bar and a hollow bar are both the same outside diameter, the solid bar will be stronger and the hollow bar--with a "typical" wall thickness will have about 60% of the strength of a solid bar. To make matters worse, the stresses in the solid bar are absorbed 100% in this thinner outer wall (means, unless it is carefully made, it can fail easier than a solid bar), whereas the solid bar spreads its stresses throughout the bar--but the outer layer still holds about 70%. Typically, a solid bar of about 21mm will have about the same strength as a hollow bar of around 32 mm depending upon material and the wall thickness of the tube of the hollow bar.

Now, we don't want to get into all this what if stuff....like what about material? what about wall thickness? etc. Sure, you can do this, but to find the answers requires a whole lot of testing. It is best to say that for any given swaybar size, a solid bar is stronger, but the hollow bar is lighter, and less strong, and so...it has to be a larger diameter to get the same strength. If you look at the Firebird 1LE suspension or even the WS6 suspension, you will see a hollow front and solid rear. The front for the 1LE is a whopping 32 mm and the rear is a puny 21 mm and in some cases only 19 mm. Also, for an example (this is for you Ricers out there....the hollow front swaybar on my Civic is 25mm and the rear is only 11mm--a rubber band would be more effective! )

GM, and most swaybar manufacturers today, are making hollow swaybars becuz they are taking advantage of a tube's ability to resist twist (assuming that the lever part doesn't bend). And, by carefully configuring the wall thickness and playing this off against the diameter of the tube, they can maximise lightness (a good thing) and still keep the strength they are looking for.

In other words, don't go changing the hollow 32 mm front sway bar for a solid 32 mm front sway bar--the solid will be way too strong.

Hope this helps.

You are correct and that pretty much reiterates my first reply on this. I talked about size difference versus strength and materials and such. Thanks for the back up.

You really can't compare front diameter to rear diameter as the front sway bars do so much more work than the rears. Years ago alot of cars diudn't even have rear sway bars.

a hollow rear bar isn't needed as you can control the rear with a pretty small diameter solid bar so the weight savings of a hollow rear bar would be minimal.

Doug

Front and rear sway bars must be compared in size and strength, just as weight bias in the front, as compared to the rear, is what determines sway bar size. Too large a bar in the rear compared to the front will induce less understeer and more oversteer. It's the opposite for the front since too large a bar in the front will induce less oversteer and more understeer. Install a 35mm hollow bar in the front with a 19mm solid rear bar and the car will snowplow right off the road. Also, use more negative camber in the front and that lessens the need for large front sway bars, depending upon what is needed, of course.

The front and rear always must be compared for weight bias and handling since one affects the other.

I didn't mean compare in that manner! I totaly agree with what you posted.

I just meant when I read your post prior to the last one you were talking about solid and hollow and size versus strength and then used the front/rear of a 1LE as a comparison. All I meant is if comparing hollow to solid you should compare a front to front bar and rear to rear bar.

I understand and agree with your understeer/oversteer comments as I have seen it myself due to trial and error over the years at different autocross events.

I also know why you have to use a certain size bar on one end and a different size on the other. Sort of like why you use larger disks on the front as opposed to the rear.

All I meant was to compare hollow to solid and thier differnces and what is good and bad about each you want to compare front to front and rear to rear that is all

I hope I cleared it up.

Doug

Sure, I understand what you mean. I was comparing two different types of bars to give readers a rough idea of relative strengths. Of course I agree with what you stated, to be most accurate a person should compare like bars to like bars. For any given bar diameter, a hollow bar is roughly 60% of the strength of a solid bar of the same diameter. In this case, it's possible to say that a hollow 32mm bar has about the same total strength as a solid 21 or 22 mm bar. However, I wonder about that myself, becuz what if the alloys are different? Any way, it is only a rough guidline. And what the person should do, is do what you did....try and compare different bars, and then decide how they want the car to handle.

Thanks man. I knew what you meant I just wanted to clarify. Solid is sure stronger but heavier and again in these days when power to weight means everything you can give up a tad bit of strength (in a street car) for the weight savings. Look at S.W.I.F.T sway bars. They only do solid race bars for the true all out enthusiast that doesn't care about a few pounds but needs the strength and flexability a solid bar gives you.

I did alot of trial and error and yeah it was expensive but for me it was part of the hobby and fun seeing what worked for me and what didn't. Plus I usually sold the parts that didn't work to someone that also wanted to try them or to someone that they would work for.

You mentioned what if the alloys are different. Man then things really change, also what about the geometry behind the bends of the bar? Those little bends if only a degree or 2 off make a huge difference between keeping the rear planted and driving off of a corner or having to pedal it around the same corner to stop wheel spin or oversteer.

I have seen heavy impala SS's with sway bars so big in the rear they look like baseball bat (but in that car with the weight they are pulling around and trying to keep under control they worked)

Have a good one Charles.

That is why I suggested people go for a ride or drive as many different set ups as possible. You don't have to spend the money and can find what you can live with. For that mater what one person can live with another might hate.

I loved my car when it had all urethane bushings but it did drive like it had a solid suspension but it handled like a lotus. Then once i was done playing at the autocross the control arms are now using graphite impregnated bushings from PST and it still handles great just not as accurate as it once did. But it doesn't have to because I don't care how long it takes me to get off an off ramp. Before I wanted every tenth of a second out of the car. I mean I went to no seats but the drivers, no interior sail panels. No carpet or sound deadening It was LOUD and harsh for 1 season. But then I decided I wanted it back to a car that I can drive everyday and still whip most everyone that tries.

I will talk to you later. Oh also. I would liek to PM you but I can't. I wish I could. That would be nice. We have alot to talk about (good stuff that is) Anyway PM me if you will I will explain. It is 11.40 here in Massachusetts if you are around I am here. I hope you get in touch

Doug