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Scot,

Cool. I like the idea of welding that type of brace in for the extra level of rigidity.

I copied your rear frame rail brace many years ago, and at the same time did the Dick Miller triangulation braces. Rear of the car definitely felt tighter and more composed/predictable, especially on the road courses.
It's visible in the attached photo if you can zoom in- underneath the rear tubular bumper.

Side question, could one do a similar front brace as that rear frame rail brace, same idea, bent or straight tube hammered into place and welded? Or is the front of the car just too crowded and/or compromises future serviceability to that area?
52DB0DA2-EA6C-42EA-B448-0BE3BAB511E2.jpg
 

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This thanks to gbhs72 : 1581105131765.png

or this from my 96 Fleetwood Limo:
192562

accomplish the same thing. The square solid steel does all the lateral and up/down stabilization needed and keeps the 1 1/2" solid steel sway bar from ripping out the mount.
 

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192564

The frame brace is welded on the side and the sway bar mount is bolted thru the brace and the frame.
 

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View attachment 192564
The frame brace is welded on the side and the sway bar mount is bolted thru the brace and the frame.
Yeah I saw those, and welding them in place definitely seems like a solid choice(ha). I was more wondering about just hammering a tube into place elsewhere and welding, and not having to disturb the sway bar area, but after taking a look at my car last night, it seems like under the sway bar is just the best place, all things considered.

That being said, how did you guys set up the sway bar bracket bolts/nuts with the limited accessibility into that part of the frame there?
Mark, looks like you drilled and tapped the plates and thread right into those without any backer nut inside the frame?
 

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As you see in the above picture, bracket under the frame, weld the lock nut into the frame, bolt thru the bottom with another lock nut ( belt and suspenders theory)
The Hotchkis 1 7/16" hollow front bar has more extreme bends than OEM which makes it longer than OEM and so makes it only as much roll resistance as a 1 1/4" solid bar. Other after market bars too. Not much improvement. The Quickor 1 1/2" solid front bar is also shorter than either bar and so has more ability to rip the mounts off the frame unless using an attachment method that is more stable. The Quickor front bar is 160% stiffer than a 1 3/8" solid bar. I stopped attempting to convince forum members long ago that the optimal balance was dynamically achieved by using F+R sway bars of the same roll resistance, ideally the same diameter, whether hollow or solid. Sacrilege apparently, even though a lot of road course testing with various shocks, wheels, tires and everything else that effects handling showed it's true.
 

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Yeah I saw those, and welding them in place definitely seems like a solid choice(ha). I was more wondering about just hammering a tube into place elsewhere and welding, and not having to disturb the sway bar area, but after taking a look at my car last night, it seems like under the sway bar is just the best place, all things considered.

That being said, how did you guys set up the sway bar bracket bolts/nuts with the limited accessibility into that part of the frame there?
Mark, looks like you drilled and tapped the plates and thread right into those without any backer nut inside the frame?
Brian, you have a PM, conversation whatever.

Mark: Snowman-33
 

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Over the last couple weekends I was able to implement my front end chassis brace/front swaybar mount. The design changed a bit and I'm pretty happy with it. Here's a sketch of the concept.



And here's the execution...















Determined mounting location so that it will clear the idler arm - used a short stub of tube on a nut/bolt as a mock up


Modified the brackets to conform with the frame and move the tube up as far as possible.


Mark out area on frame to clean up for welding


Brackets were sandblasted, painted, then the paint removed from the weld area.


Loosely assembled and welded the brackets in - not my best welding, but it will hold.




To mount the sway bar, I should have made the brackets a bit longer (but I didn't...) so I had to weld on some extensions so the bar could be mounted back farther which helps with spindle clearance. These welds are much better...







It's a close fit between the idler and the swaybar...but it clears


I was able to use M10 locking tab nuts with wings on them for easy install without needing to hold the nuts


The brackets were welded to the frame, one of the 1" nuts was welded to the pipe which was cut about 1/8" shorter than it needed to be. The other 1" nut was hammered in the pipe, then the bolts were tightened so the hammered in nut could slide to where it needed to achieve the correct width for where the brackets were welded to the frame. The last nut was tacked and then the pipe was removed and welded out. Sorry, no good pictures of those steps...

Final install (less painting/finishing and a couple minor things on the control arm end of the swaybar)
 

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One thing that I did run into with the above frame brace/swaybar mount was that the swaybar ends up being mounted about 2.5" lower than it used to be. I initially didn't give this much consideration given what others have done - I figured that I would just shorten the end links at the control arm a couple inches and that would be fine. It soon became obvious that it would be a problem when articulating the suspension through it's range of motion...

The tie rod end at the spindle and the swaybar want to occupy the same space when at full compression and full steering lock. This is shown with a 1/2" longer swaybar end link (no compression on the rubber bushings and the bolt is thread in about 2 threads to the heim joint), so making it shorter would make it even worse.


While an unlikely combination of events, if it happened the risk of damage, and more importantly, safety of myself and others was high. Moving the sway bar mounting back a few inches helped this quite a bit. The swaybar can't move back any farther since it clears the frame by ~1/4" on each side at the ends since this is where the frame widens to house the coil springs.

I don't know if anyone else has run into this issue or not? If so, how did you solve it?

My current plan is to make the swaybar end links 1" to 2" longer which should push the sway bar "up" enough to clear the tie rod end. I could also put a 1/4"-1/2" saddle on the lower control arm to effectively lower the bump stop location to limit suspension compression travel or a combination of these two solutions.

The swaybar looks pretty level (not sure if that matters?) as shown below, at ride height, when mocked up with a 1/2" longer end link, so hopefully I can just make the end link longer and that will solve the problem.
 

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I think you're in slightly uncharted waters with this particular custom concoction, haha. I really appreciate you taking the time to document and share this process though.

I do want to get some kind of brace bar in the front of my track car to minimize flex at full lateral load and keep the front tires more square on the ground. All good inspiration!
 

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IF that is the 1 7/16" Hollow front sway bar from Hotchkis:
You would have a much easier time w/ fit by replacing it with any solid 1 1/4" front bar and the roll resistance of both bars would be about the same. Hotchkis was heavy into cosmetics back when they designed this bar (see their Engine Bay Brace-waste) and wanted to have the FAT bar. They made two mistakes. The hollow 1 7/16" bar had to bend more than OEM, which made it longer , which reduced it's roll stiffness, combined with hollow= about the roll resistance of everyone else's 1 1/4" solid bars.
The brace is terrific and has the effect of making any front bar more effective so you lose nothing by swapping to the 1 1/4" solid. Any 1 1/4" solid rear bar or any 1 3/8" hollow rear bar makes for a more neutral B-body. D-body too.
 

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Chicagoareabmx - I think that's the nicest way I've heard anyone put that :) Usually it's WTF...you want to do what?, I don't know, good luck, you're on your own.

scot - the front bar is the 1-5/16 hollow bar and the rear is a 7/8" "adjustable" (by changing the end link location) - both from SpeedTech. Not looking to auto cross it, but like a neutral to slight understeer handling car on long sweeping curves.
 

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Speed Tech front bar, like my comments on Hotchkis, cosmetic goof. A 1 5/16" hollow bar has the roll resistance of the OEM 1 3/16" solid bar, if it's the same length. . Clueless to think the weight savings of a hollow bar accomplishes anything and to make it worse, like the Hotchkis bar, it appears longer with more radical bends in order to fit, which makes it have even less roll resistance than the OEM bar, which is why you're having the hassle fitting it with your brace. The brace... which is great and the added weight detracts not one tiny bit. Your 7/8" adjustable rear bar? Given the geometry of the rear suspension I see why it's 7/8" as that's also less roll resistance than the OEM 1 1/16" regardless of end link location or if it's hollow and with the front Speed Tech bar they retain the OEM understeer bias just with more body roll. My handling recommendations have nothing to do with autocross, given the weight distribution of B-bodies, having F+R sway bars of equal roll resistance makes for a more neutral dynamic but the front weight bias is tough to over come. You can induce massive oversteer with a giant rear solid bar and a smaller front bar but that's counter productive. A better way to get all the effects of the Speed Tech bars is find a junk yard with any base FE1 suspension and use the 1 1/16 front bar (~5 dollars?) and no rear bar. Speed Tech and FE1 OEM = a difference without a distinction.
 

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Fix until broke, couldn't be more true, haha. Trust me, I understand slightly uncharted waters that might not make sense to a lot of people, but can be highly effective for our oddballs. Case in point, my choice of road course mule:
192754


I'm fighting pretty bad outside shoulder wear on my car when tracking, despite big ol' sway bars, tons of posi caster and -2.0 camber. Next moves will be a front frame brace(Scots rear brace has seemed to help my car a lot), shorter upper control arms with delrin bushings and tall upper ball joints, so the DIY front brace is very relevant to me at the moment.

This car you're modding, is it a wagon? Older gen
PITTRACENICE.jpg
sedan? I forget at the moment.
 

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Speed Tech front bar, like my comments on Hotchkis, cosmetic goof. A 1 5/16" hollow bar has the roll resistance of the OEM 1 3/16" solid bar, if it's the same length. . Clueless to think the weight savings of a hollow bar accomplishes anything and to make it worse, like the Hotchkis bar, it appears longer with more radical bends in order to fit, which makes it have even less roll resistance than the OEM bar, which is why you're having the hassle fitting it with your brace. The brace... which is great and the added weight detracts not one tiny bit. Your 7/8" adjustable rear bar? Given the geometry of the rear suspension I see why it's 7/8" as that's also less roll resistance than the OEM 1 1/16" regardless of end link location or if it's hollow and with the front Speed Tech bar they retain the OEM understeer bias just with more body roll. My handling recommendations have nothing to do with autocross, given the weight distribution of B-bodies, having F+R sway bars of equal roll resistance makes for a more neutral dynamic but the front weight bias is tough to over come. You can induce massive oversteer with a giant rear solid bar and a smaller front bar but that's counter productive. A better way to get all the effects of the Speed Tech bars is find a junk yard with any base FE1 suspension and use the 1 1/16 front bar (~5 dollars?) and no rear bar. Speed Tech and FE1 OEM = a difference without a distinction.
scot - thanks for the info. I have the stock 1-3/16 bar and I did a rough comparison between them and they looked the same (same bends, same locations, same shape, etc - just to make sure that they didn't ship the wrong bar), but I'll look at them in more detail this weekend. I'd think that if it were longer than the stock bar that I wouldn't have had to slide it back as far to make it fit decent around the tie-rod ends? It's definitely not longer from side to side compared to stock as the rubber bushings were "into" the bend in the OEM sway bar mounting locations.

No illusions about weight savings with the hollow bar - it's what was in the package (along with the rear bar). I made the (somewhat uneducated) decision to purchase a complete suspension system rather than try to re-invent the wheel piece by piece. I'll give it a shot as it's intended, but good to know of other bar options in case I'm not happy with how this work out.

Chicagoareabmx - the car is a 96 Roadmaster Wagon with a 6.6 Duramax engine swap.

A few more details here...



 
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