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Discussion Starter · #1 · (Edited)
Here’s a little Christmas gift for my Sky and Solstice people. (lol)

I had to relocate my front sway bar on my car a few weeks ago and also did a little mod I figured I’d pass along. This is a little trick I learned WAY back when I had a ’74 Firebird and it needed a lot of help to make that ‘70’s suspension design a little less boaty. One of the things I did was to shorten the leverage point of the bar by moving the link mount hole. Shorter sway bar arm= more force needed to twist bar.

When I was making my sway bar brackets, my goal was more rigidity and more sway bar strength. The more ridged you make the mounts, the less free movement you get before the sway bar starts to actually work. The mounts I made are two-piece billet aluminum with 5 mounting bolts to hold it all together. I don’t think there will be much slop in the bar movement!

My other goal was to increase sway bar strength to help with the added V8 weight. Even though these bars aren’t like the old ‘70’s sway bars in that they’re hollow instead of solid bars, there’s still enough material at the ends of the bars to move the link mount hole. I was able to move the mount hole in an inch without compromising the bar end strength whatsoever. The pivot length of the front bar is about 7 inches stock, it’s now 6 inches on my front bar. (I plan on doing the same to the rear, haven’t gotten there yet.) That means I’ve increased the sway bar strength approximately 14.3% over the stock Z0K bar. If this ends up being too much for the front, all I’ll have to do is move the links to the stock, rear holes. I don’t think ~14% will be too much for the front or rear with the rest of the changes I’m making to the car.

The best part of this mod is IT’S FREE!!! If you can figure out how to remove a sway bar to replace it, then you can probably handle drilling a new hole and grinding away a little bit of the angle to make sure the link stud and nut fit flush with the bar. If you keep the new hole closer to the old one, you won’t even have to do anything else but drill the hole. That would get around a 10% increase in bar strength with very little work. I would be willing to bet the holes could be drilled without even removing the sway bar from the car. The worst that could happen is you’d destroy the bar (highly unlikely) and have to buy a new one. Best that can happen is you spend an hour or so in your garage and drive out with sway bars that are between 10% and 14% stiffer than stock FOR FREE! The added benefit is you still have a stock, GM made factory sway bar that is a know stiffness and you're doing a known and easily calculated increase to that stiffness.

Merry Christmas guys!















 

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Great idea. When are you going to start a LSA build thread?
 

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Were did you get the sway bar bushing
holders?
Great post.
LLLFLY
 

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Thanks Santa. Assume this would theoretically work regardless type of OEM sway bar? And just so I'm clear, are you saying all styles of OEM Kappa swaybars are solid?
 

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No they’re hollow instead of solid bars
 

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I haven't confirmed your math, but it makes sense.

However, I'm not sure this adds 14% rigidity. It makes sense that it puts 14% more stress on the bar, but like you said, your '74 Firebird had solid sway bars. These are hollow. They are not intended to handle that much stress and they are not over-engineered like your Firebird bars from 40 years ago. I think its likely that the additional stress will bend the bar over time, and that once this bending starts to occur, it will actually decrease the rigidity below factory spec.

However, its also possible that the bar will stand up to the stress. But I think only time will tell.

If you want to be sure, measure the distance from hole-to-hole with the bar off the car, and then take the measurement again a few months down the road and see if they are the same. If the distance has increased, you know the bar is bending and you'll need a new one.
 

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Hollow bars are stronger than solid bars, pound per pound. Shortening the bars by one inch will increase the stress on them. OEM stuff is so over engineered, bending is very unliklely.
 

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Discussion Starter · #9 ·
I haven't confirmed your math, but it makes sense.

However, I'm not sure this adds 14% rigidity. It makes sense that it puts 14% more stress on the bar, but like you said, your '74 Firebird had solid sway bars. These are hollow. They are not intended to handle that much stress and they are not over-engineered like your Firebird bars from 40 years ago. I think its likely that the additional stress will bend the bar over time, and that once this bending starts to occur, it will actually decrease the rigidity below factory spec.

However, its also possible that the bar will stand up to the stress. But I think only time will tell.

If you want to be sure, measure the distance from hole-to-hole with the bar off the car, and then take the measurement again a few months down the road and see if they are the same. If the distance has increased, you know the bar is bending and you'll need a new one.
Soooooooo, I'm not sure you know this, but I've worked on a couple more cars and modified a couple more sway bars since 1977 when I was messing around with that Firebird. For instance, 1979 was the first year I worked on an Indy 500 pit crew. Fast forward a few years and a few tens of thousands of cars through my stall or shop later and I'm still being paid to work and consult on race cars. This isn't the second sway bar I've ever looked at. lol.

What I did to the sway bar will outlast the car. And measuring the sway bar "hole-to-hole" wouldn't even be a valid test. If a sway bar is going to weaken or fail, it's not going to spread the arms further. That doesn't even make sense. BTW, do you really think a '74 Firebird was "over-engineered" compared to a 2008 Sky? Really?
 

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LSA build thread?
 

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Discussion Starter · #11 · (Edited)
LSA build thread?
Sorry Jim, not gonna happen. There are a hundred other far more difficult "mods" than this one that I've done to my car. Can you imagine how much work it would take for me to explain how to cut the engine support crossmember out, design and build a new one to lower an LSA further and farther back than anyone else has done, weld it back in and paint it? With the risks being little problems like the engine falling out or the rear mounting points for the front A-arms snapping off?

Or how about making an MGW C6 billet shifter work with a CTS-V universal joint shift shaft welded to a stock C6 shifter pivot sitting on a custom made billet mount using ZL-1 style shifter brackets, mounted to a CTS-V TR6060, with the other end of the shifter housing attached through a rubber filled aluminum block to the tunnel of a Saturn Sky? lol. No Thanks.


Were did you get the sway bar bushing
holders?
Great post.
LLLFLY
From my post-

When I was making my sway bar brackets, my goal was more rigidity and more sway bar strength. The more ridged you make the mounts, the less free movement you get before the sway bar starts to actually work. The mounts I made are two-piece billet aluminum with 5 mounting bolts to hold it all together.
If you look in the background of the first picture you will see where I got the bushing holders from.

 

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Hollow bars are stronger than solid bars, pound per pound. Shortening the bars by one inch will increase the stress on them. OEM stuff is so over engineered, bending is very unliklely.
I understand hollow bars are stronger pound-for-pound, but the old solid bars weighed a ton more. That's why they are not used anymore. They were stronger, but they didn't need to be that strong. If people in this thread say that the OEM bars won't bend then that is good enough for me. I was merely raising an issue that wasn't addressed in the OP.

Soooooooo, I'm not sure you know this, but I've worked on a couple more cars and modified a couple more sway bars since 1977 when I was messing around with that Firebird. For instance, 1979 was the first year I worked on an Indy 500 pit crew. Fast forward a few years and a few tens of thousands of cars through my stall or shop later and I'm still being paid to work and consult on race cars. This isn't the second sway bar I've ever looked at. lol.

What I did to the sway bar will outlast the car. And measuring the sway bar "hole-to-hole" wouldn't even be a valid test. If a sway bar is going to weaken or fail, it's not going to spread the arms further. That doesn't even make sense. BTW, do you really think a '74 Firebird was "over-engineered" compared to a 2008 Sky? Really?
There's no reason to be condescending. If someone has a minor challenge to what you're saying, you can address it without resorting to mockery.

Yes, old cars were absolutely over-engineered in many components. Over-engineering doesn't mean there were too many engineers on the project, it means the part in question was stronger than it needed to be: Overengineering - Wikipedia, the free encyclopedia

All-steel bodywork was the norm in 1977 but no longer. Solid steel sway bars were apparently the norm, but no longer. Those components were over-engineered. That is to say, they were more robust than they needed to be.

As I'm sure you're aware, since the 70s, technology and laws have changed so that weight is a much more important factor (owing mostly to CAFE standards) so we switched to aluminum and fiberglass bodies and hollow sway bars instead of solid steel to lighten cars.

Those components were over-engineered. Now they are properly engineered, which means the tolerances are closer to what is needed.

As far as spreading the arms further: if the bar were to bend, that is exactly how it would bend. The original bolt holes are further apart. By putting new holes closer to the center, you are putting additional outward tension on the bar.

In fact, increasing this tension is the entire goal of this project. You are intentionally flexing the sway bar outward, so that it will take increased force to flex it more.

My concern was merely that this has the possibility of permanently bending the sway bar.

If you're saying that its impossible for that to happen, then I'll defer to your years of F-1 experience and tremendous ego.
 

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GMTech, these totally rock, are you making rear ones too? Also appear to be machined for greasable zerk fittings? I bought a set of the new Werks adjustable sway bar I wouldn't mind having a set of these trick brackets made for.
 

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Both the mutliple holes and the alloy mounts are normal stuff on race cars and do exactly what he said they do. I will freely admit that none of the mounts I've fabricated look anywhere near as pretty as those!

And no, the bar won't bend (except in the way it has to to function).

I see most people wanting to use stock front and ZOK rears, perhaps because that seems to work best for slalom competitors, but I quite like the ZOK front and rear. Let us know how the added stiffness works out in terms of handling - very nice to be able to do an A/B comparison with only 10 minutes work.
 

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Discussion Starter · #15 ·
There's no reason to be condescending. If someone has a minor challenge to what you're saying, you can address it without resorting to mockery.

Yes, old cars were absolutely over-engineered in many components. Over-engineering doesn't mean there were too many engineers on the project, it means the part in question was stronger than it needed to be: Overengineering - Wikipedia, the free encyclopedia

I am so sorry. I apologize for being condescending. I had no idea you were someone that had the immense power of wikipedia behind their opinions. Please accept my apology, I'm so ashamed of myself.


Seriously, if I did "mock" you, maybe it had something to do with the VERY FIRST 5 WORDS OF YOUR VERY FIRST SENTENCE. I didn't make this thread so someone could "confirm my math". Really? Of course the math isn't EXACT, I didn't really care about an exact number. I think I said "approximately" 14.3%. I even used one of these squiggly lines ~ . If I wanted an exact number I would have had to use the exact distance between the hole centerlines, which was actually more like .9834". And I would have had to add in the fact that the arms are not at 90 degree angles, so the 7 inches was a rough measurement. The pivot points are also not in line with the line of force, so there is also some deflection involved, which I did not factor for. (Or would I have any idea how to factor for. lol) On top of all that, there is the actual metallurgy of the bar. Is the spring rate of the steel uniform? Does moving the point of force 14.3% further towards the pivot result in an EXACT 14.3% increase in twisting force? I have no idea. And I have absolutely NO interest in going to wikipedia for the answers. I don't base my opinions or knowledge on the internet. I base it on what I've actually had my hands on and what my actual eyes have seen. I had my hands on cars built in the '70's and '80's, and now on the '14's, pretty much every day of my life. Your statement about cars in the '70's being "over engineered" is hilarious. After all, the cars made in that time period were some of the finest pieces of engineering ever made in the history of cars. What I would give to be driving an '80's X body GM car or a Chrysler K car! Damn those cars were over engineered! And that '74 Firebird that put out like 175hp from a 400 cubic inch V/8? If you tried to get 250hp out of it, or rev it over about 5k you'd blow the UNDER ENGINEERED rods right out of the block! Hella lolz!!!

I'm not an Engineer, I estimated what the increase would be, and expressed that when I clearly said "approximately". I came up with 14.3% by taking 7 inches as 100%, finding that 1/7th of that would be around 14.3%, and then rounding up the distance I moved the hole to an even 1 inch, which "should" mean an increase of 1/7th, or 14.3%. Your very first response was to imply that if my math could not be "confirmed", you would then question the entire premise of the mod. I did not post this to have my math confirmed. Maybe I should have dumbed it down further and not even stated a number at all. It increases the strength of the sway bar's effect. I actually have no idea how much. How's that?
 

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Discussion Starter · #16 ·
Both the mutliple holes and the alloy mounts are normal stuff on race cars and do exactly what he said they do. I will freely admit that none of the mounts I've fabricated look anywhere near as pretty as those!

And no, the bar won't bend (except in the way it has to to function).

I see most people wanting to use stock front and ZOK rears, perhaps because that seems to work best for slalom competitors, but I quite like the ZOK front and rear. Let us know how the added stiffness works out in terms of handling - very nice to be able to do an A/B comparison with only 10 minutes work.
Thanks Bill. And yes, you could literally do an A/B comparison in 10 minutes. That's the ONLY way to assess changes like this. Unfortunately it will be another month or two until I can actually drive my car! The car is not coming out of my shop until EVERYTHING is finished, that means all the interior stuff too. Since I can only work on it in my spare time, it's gonna be awhile longer until I can actually test out the bar mods. As you know though, it's a common practice and it will do exactly what I think it will do. Adjustable sway bars in race cars basically have a sliding end link that can be moved from the inside of the car or through a hole in the body. And yes, I've seen a lot of guys using the stock front bar too. That old Firebird did show me very clearly what too much sway bar can do, I remember that! (I went WAY further than just modifying the stock bar.) I never felt like the Z0K front was too strong, it's more like the Z0K rear bar just isn't enough. Having a V/8 up front and the fact that I'm going to try to go quite a bit stiffer than 14% on the rear bar should get me close to the right amount when it's all done. In theory of course!
 

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GMTech, these totally rock, are you making rear ones too? Also appear to be machined for greasable zerk fittings? I bought a set of the new Werks adjustable sway bar I wouldn't mind having a set of these trick brackets made for.
Agree with Chop Top I also would be interested in a set of these for my car as I am doing a suspension upgrade this winter
 

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It would be nice if someone made solid sway bars for the KAPPAs, especially for a V8 swap.
Why?

The whole point of hollow bars is to get the stiffness you want with less weight. How would you improve that by going to a solid bar - you'd just make them heavier, not better.

The reason that solid was the standard in the past was cost - easy to take rod stock in the right diameter, bend and heat treat it. Not so easy to create a hollow bar with the wall thickness you want. Car manufacturers and big sway bar outlets like ADDCO can do that economically.

I run pretty heavy bars on my Fiero - 1 1/4" front and 1" rear, solid. I'd lve to have had suitable hollow bars on principal even though it is a street vehicle, but they aren't available. A hollow bar of the same stiffness would be larger OD but up to 40% lighter.
 

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