Torsion Bars - 318 to 440

[Kern Dog]

The frame connectors on the second car are 2x3 and welded flush to the bottom of the existing frame rails. No connection to the floor pans. I do plan to weld .090 thick plates to the LCAs, I may even spring for the US Cartool lower core support brace for both cars. I made my own torque boxes too.
With the red car, I noticed right away that the torque boxes and frame connectors reduced shakes and flex on rough roads. The car felt as if it just soaked them up instead of skipping and bouncing over them.

[Kern Dog]

The XH Charger:

[c00nhunterjoe]

Nice. Welding them to the floor pans will make a dramatic improvement as well if thats an option. I would fully weld the k frame and reinforce the steering box area before i did the core support. If you are not replacing the floor pans which would allow access to the anchor pass thru, at least add some reinforcement to the outside of the t bar anchor point on the frame.

[c00nhunterjoe]

Its hard to tell from that angle, but are the supports circled welded to the frame connectors?

[Kern Dog]

Sorry that it took me so long to respond.
I was banned for a week or so. Somehow, I just tried to log on a few minutes ago and it went through like before.
To answer your question, No.
The connectors are 3x3 .120 wall. I welded strips above the connectors to follow the contour of the floor pans because I wanted them to have no gaps above, completely for cosmetic reasons.
I did reinforce the LCA pin mounts in the K member, welded in gussets around the steering box mounts, seam welded the entire K member, add3d plates to the bottoms of the LCAs too. I am tempted to add in the US Cartool lower radiator brace.

[c00nhunterjoe]

Nice upgrades

[c00nhunterjoe]

While bored out of my mind on quarantine, i threw the tahoe up on the lift today to give some further perspective into the discussion. This is a full size, full frame truck with the same design front suspension as our b bodies. The tahoe runs a 1.15" bar that has an effective length of 48 inches and a swing length of 13 inches. I will not bore you with the formula used to calculate wheel rate of a bar but the truck uses a 248lb bar. That is a vehicle designed to both haul 7 people and tow 6500 lbs and weighs 5100 lbs.

[Kern Dog]

Thank you.
I was not school trained in what I know or have done. I've read magazines, books, taken in advice from people online, etc. I've built several cars that run well and perform admirably.
I don't know the math on these things, I just know what feels right to me. I don't begrudge someone that is properly trained, I just know that in areas such as Construction Engineering,  as a Carpenter I  often find errors in design that the "Smart guys" make and that I have to correct. More often than not, the Engineers do have it right.

[c00nhunterjoe]

In my experiences, having a degree hung on the wall does not necessarily make you smart.

[c00nhunterjoe]

https://swayaway.com/tech-room/torsion-bar-wheel-rate-calculator/

Here is a site with alot of good reading. Gives alot of the formulas for calculations as well as more details into how chassis and suspension component flex affects the spring rates.