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Discussion Starter · #1 ·
So my 94 s10 mid engine thing has leafs in the back. From the start the plan was to run caltracs. But looking at other similar s10's and comparing it to my own the caltracs sits dangeriously low and will probally hit stuff as this is meant to be driven on Michigan roads where a 6" pothole(on the highway), 4" railroad track, or just stupid real world grade changes are things you encounter.

So been looking at what caltracs do and other options then looked at my own pile. I have a nice amount of room over the axle. What if I put the triangle up there?

I made a simplistic sketch and think it should work.
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My leaf spring perches are already 1/8" thick so I think I can just weld a 1/8" shock mount to that and of course gusset and brace it.
Then I have a small rod which is the adjustment rod.
That connects to the triangle with the top of the triangle having a fixed point on the frame and a bushing so the triangle can rotate.
Then I have the big rod which might be a piece of tubing or square stock going to the spring bushing bolt. With a U at the front so it stradles the bushing bolt with bushings allowing it to move.
The big rod will have a rubber bumpstop on the bottom almost touching the spring.


When the pinion is rotated up under hard throttle the small bar is pushed up, big bar pushed down, bumpstop pushes down against the spring, and it should prevent axle wrap.



But before I spend $200+ and a few weeks figuring this out.

Is there a issue where this won't work?
Does someone already make this setup?
 

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1979 Chevrolet Malibu 496-TH400-9" (cruiser). 1992 Chevrolet S10 355-700r4-7.625" (daily driver).
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I would look at the traction bar setups being used on rock crawlers for inspiration.

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I have no experience with anything like this. I just tried to think of a situation where traction bars might be used where clearance was a primary concern.
 

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If you understand how the Cal-Trac bar works, you would realize what you have drawn up won't work.

What the Cal-Trac does is turn the leaf stack into the upper bar of a 4-link, while the Cal-Trac bar itself is the lower bar of the 4-link.
The front triangular rocker pivot directs force back into the spring leaf just to counter the springs own natural tendency to bend upwards under power application right behind the front eye.

The front rocker pivot was just an ingenious way of allowing the front of the bar and the spring eye to have separate pivot points to prevent binding up during suspension travel and not just making the suspension super stiff like the old fixed location front mount on the Traction Masters developed in the 1950's

John Calvert's brilliance was figuring how to use some of that force put into the lower bar to also control the spring wrap.
It is the mounting point of the front lower bar that uses multiple holes to get instant center adjustability that is the most important aspect of the bars ability to work.

If you want to see the adjustability carried to the extreme, look at Smith RaceCraft Assassin Bars
 

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If you can get the ratio worked out to match vehicle weight and rotation around the pivot contacting the main leaf at it's weak point ( 1/2 way in between spring eye and end of next leaf in the stack is a good general point for multi leafs), then the last sketch layout should work.

Have you thought about something like a flipped over Competition Engineering Slide-A-Link??
It is similar to the Cal-Trac, but more simplified at the spring eye and main leaf clamp end of the bar.
 

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Discussion Starter · #7 ·
I think a normal bar will be enough if I get the geometry correct. Good enough anyway. I dont care all that much about a 60ft time I just dont want the thing to break parts due to wheel hop.

At this point I just need to make sure to leave the area open for the large bar and upright. Not put coolant, brake, electrical, fuel lines, exhaust brackets etc in the area.

On the upright itself I am thinking of having the upper portion bolt to the axle housing/u bolt flange. This will let me make several designs (changes) without welding to the housing multiple times.
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6" pothole? i went across a pothole on ford road that had a temp bridge on it last night...

easy way is to keep the stock springs and weld up a simple torque arm
the reason caltrac uses the triangle is to allow free movement up and down without twisting the rearend
a simple torque arm with a trailer spring shackle up front does the same thing
i run an 86 trans am rearend that came with coil springs and a torque arm on stock 58 springs
i ran without the torque arm for a year, the axle would wrap up and hit a x-member on the driveshaft
to install a torque arm on leaf springs without binding i had to make a slide joint or double pivot

oem torque arm bolted into the bosses, the trans am front mount was a slide into a rubber mount

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i had an x-member right behind the front u-joint that i made the pivot. it's just a short trailer spring shackle.
if i hadn't done this the axle movement would have been locked in by triangulation of the frame, springs and torque arm

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a torque arm could be as simple as 2x2 square tubing bolted to a spring pad welded to the axle
then use the trailer shackle up front,
 
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