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Should I be lucky enough to own another B- or D-car, SO doing this and the Dick Miller Racing Rear Triangulation Braces!
 

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95wagon - I like the look of those Cantrell connectors and not horribly expensive either compared to 1" nuts and bolts.

scot - I can cut/weld if necessary, but would much rather not if I don't have to. Agreed that welding is the easy way to make two pieces become one :)

I'll need to order material soon to get it in time for this weekend.
 

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FUB wrote: "I like these braces because they tie the front end together left/right wise well so steering inputs don't go into flexing the frame, they actually turn the wheels. One thing I've always thought could use some improvement was the up/down strength that they add."

The part of your question my pictures answer. The welded brace at least doubles the "up/down strength" of the frame horns and similarly does for the steering box, as well as addressing your "left/right" comment. The "at least doubling" is the product of both frame ends having to move up or down if one does. Like boxing the C-channel as that has spring rate too. Actually about 20 years ago I wrote posts about welding 1/8" thick pieces of steel into the C-channel about a foot apart, making the channel almost as strong as boxing would for about 5% of the effort of boxing.
 

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Gerry, cool mention on those connectors. I'll have to try and remember they exist if I ever take on a project that could make them useful.
. Like boxing the C-channel as that has spring rate too. Actually about 20 years ago I wrote posts about welding 1/8" thick pieces of steel into the C-channel about a foot apart, making the channel almost as strong as boxing would for about 5% of the effort of boxing.
Not a bad idea !
 

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FUB wrote: "I like these braces because they tie the front end together left/right wise well so steering inputs don't go into flexing the frame, they actually turn the wheels. One thing I've always thought could use some improvement was the up/down strength that they add."

The part of your question my pictures answer. The welded brace at least doubles the "up/down strength" of the frame horns and similarly does for the steering box, as well as addressing your "left/right" comment. The "at least doubling" is the product of both frame ends having to move up or down if one does. Like boxing the C-channel as that has spring rate too. Actually about 20 years ago I wrote posts about welding 1/8" thick pieces of steel into the C-channel about a foot apart, making the channel almost as strong as boxing would for about 5% of the effort of boxing.
scot - we're in agreement that welding is the easiest way to get the most rigidity between two parts. The 3x5 box tube that would connect to the frame would be fully welded around the perimeter (and some of the inside as well) so should be "one" with the frame. Actually, it will likely be stiffer than the frame. I would really like the cross tube to be removable, so I'm considering other designs.

The 1" box tube on your car that bridges the gap between the frame ends will have some flex in it when one frame end moves up and the other stays still. Would you agree that a 1.9" diameter round pipe would have the same or less flex over the same distance with the same loads applied?

If so, then the only part that I can think of left that would have some flex in it is the bolted joint holding the cross tube to the box tube. A 1" bolt at 600 ft-lbf torque will generate about 50,000 pounds force of clamp load. Just for some quick "back of the napkin" engineering here - the flange diameter of a 1" flange nut is 2" in diameter (1" radius). So, with the nut welded to the pipe and a bolt pulling the nut tight against the box tube with 50,000 pounds of force at a 1" radius, it would take 50,000 in-lbf of torque to "unload" the joint (4,166 ft-lbf). The distance between the frame rails is right around 36 inches, so if we divide 50,000 in-lbf by 36 inches we get 1,388 pounds of force on the opposite frame rail before the bolt unloads. I don't know what the forces actually are in a cornering scenario, but 1300+ pounds feels sufficient being that it's basically than the corner weight of the car.

I agree that if it was welded at all points that would be best, but given that I want the cross tube to be removable (without a plasma cutter/sawzall/grinder/welder), this is what I came up with.
 

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It's all a trade off, bolting (regardless of method) is better than no brace. Boxing is better than gusseting. Sometimes weight matters (Bentley never heard that one), see my Arnage.
One thing not obvious. The 1" bar "that bridges the gap" is not a box tube. It's solid steel. Just like the 1 1/2" sway bar is, and for the same reasons. Even on a 8,000 pound car, I can
sometimes make a choice with an eye on weight (unlike Bentley). Also the seam welding and gusseting was already done when the brace was made. Law of diminishing returns comes into play eventually. Specialty Vehicles International once contracted Progressive Automotive to build a super rigid B-body frame ($11,000; in the 1990's). Bolted under one of our $100,000+, 6-speed, supercharged Impala SS's for export to Jordan. Custom suspension, supercar tires and wheels. Improvement with Progressive frame in handling, braking, ride and noise? Undetectable. Such is the Law of Diminishing Returns. Choose with wisdom grasshopper.
 

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Lot of triangles on that Bentley.
Name of the Bentley with the GM 4L60E is Arnage. Though to be fair Bentley takes the new 4L60E trans they buy from GM and replaces the Sun Shield and all the clutch packs and a few plastic pieces.
New trans from Bentley does cost nine times as much as new trans from GM though. Do the upgrades yourself to a new GM trans cost about 700 USD. Handles the 600 ft. pounds of torque from the 6.75 liters easily.
 

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Name of the Bentley with the GM 4L60E is Arnage.
Though to be fair Bentley takes the new 4L60E trans they buy from GM and replaces the Sun Shield and all the clutch packs and a few plastic pieces.
New trans from Bentley does cost nine times as much as new trans from GM though. Do the upgrades yourself to a new GM trans cost about 700 USD.
Handles the 600 ft. pounds of torque from the 6.75 liters easily.
4L60E? or 4L80E?
Could swear Rolls Royce & Bentley used the TH400 since the early 60s, then switched to the 4L80E in the late 80s or early 90s?
 

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View attachment 192479

1 3/8" hollow sway bar with Pro-Touring brace and 1/4" spacer on 94 SS View attachment 192479
Scot,

I'm guessing the only reason for the spacer stack is to provide clearance between the brace and bar as it rotates?

Also, forgive me ignorance, but does having it welded in like that complicate any particular maintenance or pulling the motor?
Looks like there's plenty of clearance for anything I could think of....
 

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Yes on the spacer.
Great question on welding. The factory welds the frame together because you literally can't have a frame that is too rigid or stiff (unlike a suspension).
Anything less rigid of a frame compromises ride, handling and braking. GM=compromise. Anything that moves the suspension can flex the frame (spring rate of the frame)
and take turning the wheel to change the direction of the car. If first that input is flexing the frame, steering is less precise. If a bump bounces the suspension
and the spring and shock transfer energy to flexing the frame, control is compromised. Of course there is a cost/benefit ratio, which is why the factory frame
isn't very rigid but it was cheap to build. A new 1994 SS cast $22,600 .See my comments in a previous post on the $11,000 frame from Progressive Automotive.
Too much cost, not enough benefit. Unlike a new 1994 SS.
So the SVI cars went off to the Middle East with seam welded and boxed frames instead (low cost, big benefit) at >$100K+ each. Sold everyone built.
Pulling the motor is going to be pulling it up and out, not down. I've previously posted pics and info on a welded brace at the rear of most B-bodies. GM did it on D-body.
Imagine an infinitely rigid frame (though impossible). The benefit of that fantasy beyond the welding/braces I've recommended would be minuscule.
 

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In an email I was asked about the braces that triangulate (triangles again!) the frame attachment points of the rear U+L control arms. They were made by Dick Miller Racing
part # 5029-w and before the dark times his phone # was 662-233-2381. They make a very noticeable difference to the rear suspension, especially on launch with mucho HP,
( pinion angle) and also prevent all binding at the rear on hard cornering. Dick was an A-body Oldsmobile 442 racer and modified the A-body design for the B-body.
 

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scot, It's good to see you back here with us. Question about the spacer. I thought I had read in one of your previous posts about the spacer lowering the sway bar to align it better with the control arms or something like that. Was I mistaken? It's the reason I welded the 1x2 inch bars to the frame with the tube welded to those. Regardless, I prefer having the mounts for the SB drilled and tapped as I did instead of the speed clips or whatever the're called. Just a more perfect union.🇺🇸

Mark: Snowman-33
 

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gbhs72 many spacers
Notice the different spacers on the two 1996 limos (different spring heights) with the 1 1/2" solid bars and the 1994 SS with the 1 3/8" bar, which are all different from the 2005 ECIRS winner 1996 Caprice. The ideal is the front sway bar end mounted level with the ground. (aligned better with the lower control arm) Those 4 cars have the front fender 29". 28", 27.5" and 25.5" off the ground so ...unique spacers.
On all I've wanted the sway bar mount more rigid than drilling and tapping because the leverage from the bars (esp the 1 1/2" solids) can rip the bushing and mount right off the frame,
which actually happened to me with my 1998 F-body with an ST 1 3/8" solid F bar.

Here is a recent picture of the 94 frame boxing after 25 years of sea coasts, alpine life and various road salt.
192483
 

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scot, I tried to follow your advice closely. If you go back to my post, #36, look close at the picture I have there. I welded the bar stock to the frame, with the tube welded to the bar, but I drilled and tapped the bar to attach the SB mount. Instead of using a stud as you did I got ARP bolts. Since I have the body off the frame I decided to weld in 3/8th inch plate. My original thought was to go with your idea of the plates. But I was at a point that it was just as easy to do the entire "C" channel. Besides, $15 for the plates cut to order and fit. It only cost a few dollars more for wire & gas.
Thanks my Friend,

Mark: Snowman-33
 

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192484

Looks great to me. As you can see, I seem to do different things all the time to get to the same place. By attaching the crossbar as you did it locates both frame ends laterally
and also requires them to move (very little) in tandem both sideways and up/down. Whenever we reinforce a weak spot it reveals a weak spot somewhere else. Like the C-channel.
With the 94 I can tell you 26 years later ...it was all worth it.
 
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