Shcroeder racing makes all kinds of splined torsion bars typically used in Nascar as sway bars. The 1.5" dia 48 spline seems to be pretty common and they can be had in length from 30 to 50". How tough would it be to make some female splined couplers that could go in place of the factory ancor and adapted to the control arms? These come it all kinds of diameters from 7/8" up to 2"+ and either hollow or solid. Would eliminate the "Mopars cant get enough front spring rate" problem for good http://www.schroedersteering.com/SwayBarPage.html
http://www.schroedersteering.com/RateChtPDFs/1-12barchart.pdf

Something like this, only bigger;


http://www.shop.lunns.net/ekmps/shops/lu...0-pr--241-p.jpg


Not enough springrate options isn't the main problem I think with Mopars.
IMO the price of a set of (seemingly simple) bars is, for most hobbyists.

How much would a set of these Schroeder bars set you back?
How much would 4 fabbed spline adapters add to that, which have to be hexed on the outside and splines machined on the inside. I'm seeing an easy $100 here aswell.

I went from factory stock 0.87" bars to the 1" bars from JustSuspension, mainly because they were affordable @ $200 for the pair, AND the fact as a newby, you don't know what to expect from a larger bar at first.
Had I felt confident upfront the 1" bars are something that should have been mounted from the factory (A-body), I probably would have opted for the bigger, but higher priced FirmFeel bars.

Having 1" bars @ $200 cost in my car now, I'm not really eager to plunk down $350 for a pair of 1.06" or 1.12" bars again.

You would need some sort of clip so they wouldn't come out of the socket too. ( both the bar and the new hex piece)
That would weaken the torsion bar.
I think there is enough range with the current available bars?

We looked at making them, and the cost was too prohibitive.

The benifit would be these are gundrilled and can be had in all different sizes but with the same 1.5" 48 spline broach. B and E bodies would benefit the most being able to go past what is possible with stock hexes. These are all over ebay for $150 pair in 37.5" length.

I'd like to see what rate you could get to where you could crack the windshield. We had to stop testing on the shaker rig because we almost did.

If you really want to easily swap between splined torsionbars I think you could fab something like this, to slide into the existing LCA and TBar anchor, and install the torsionbar in between;

(Quick Photoshop-mockup. Dimensions are wrong)

Come to think of it, the above won't work with fixed tbar anchors.
(I was thinking about the removable anchors the pre'65 fullsize Mopars have.)

The rear hexes need to be 86'd for the female sleeve. Like I said earlier, it would have to be a conversion not an adaptation.

Just a brainstorm, carry on.

IMO Mopars are for sure sprung way to lite from the factory but...
( again IMO) there comes a point when too stiff of a torsion bar just masks the real issue of the front end geometry not being optimal. Too stiff and you basically have little or no suspension, so the negative movement's don't happen, it's just a bigger go-cart. With Mopar's and any unibody design the whole car is a big torsion bar. I'f you limit it too much in one area it has to flex at the next weakest spot. Popped spot welds, ripped out mounts, broken windshields etc...
Unless your doing some serious high speed/high banked road course racing I'm guessing Firm Feel has us all covered?
If your building a dedicated race car that's a different story, they are a "consumable" and not intended to last indefinitely. "Lifespan" is below being competitive on a priority list. No one builds race cars to last 40 years. Most everyone on here runs our cars mainly on the street .
Just my

Just did a few calculations:

Hex opening: 1,25" - no larger TB can be fitted through the TB anchor.
1,5" spline bar ends have enough meat to be machined down to a hex of 1,25" (distance between opposite flat sides not corners).

So if you get splined bars with 1,5" ends and a diameter no larger than 1,25" you could turn them into regular hex bars if you have access to the necessary machining equipment.

Unfortunately most bars I keep finding in the right diameter are only 37.5" long...

Cudazappa (Gary) - The 1.24 TBs are rated at 425 lbs/in. As you know, my car was originally setup for national SCCA Solo II competition (first it was F/Stock, later E/Street Prepared.. a great fun class!)... flat smooth courses (airports, huge parking lots, etc). Progressively changing the TBs also went with changing the rear leafs, as well as the shocks... eventually changing the valving on the Konis to better match the TBs and leafs. The sway bars were also progressively changed in their diameters... fine tuning them with the different combos of end-link bushings (rubber/poly), same with the adjustability of the Koni shocks -- all to my personal satisfaction, as well as with input and track-testing (pylon events) by a few highly regarded and pro-racers. Limits were restricted by SCCA class rules.

After campaigning it for well over 20 years, fine-tuning, etc, it handles pretty good and will keep up with anything out there (and I've taken a break/hiatus sionce ~2001 ~2010). Just ask anyone who's driven or raced it. The ultimate matter depends upon having fresh soft tires, and the skill of the driver on that given day. also, pylon courses mandate the driver to memorize the course layout, and positioning of the car, etc -- a huge factor in time for any day's competition autocross results; road courses also mandate familiarization, and lapping experience is a plus!

Hi-speed road course events is what I've been doing for the past 3-4 years as time and $$ allows -- car handles great... pretty much the same setup as I've settled upon many years ago (actually, its a little heavier with minor changes). Again, limiting factors are just the tires.

Street/hwy driving with the car's stiff setup is no big deal... no cracks, broken welds, windshiled, etc... I have different rims/tires pending where/what I'm doing with the car; naturally, driving on the "street" requires avoiding pot-holes, slow-crossing over RR tracks, etc... I've said before... "street" driving doesn't count as you can't truly enjoy the car; highway driving is great and very enjoyable!... typically 1-2-3 hour (sometimes longer, even cross-country!) driving is no problem... comfort is a-ok.

In retrospect, look at the size of the Posey TA/Gurney AAR cars' TBs (and leaf springs)... I beleieve the TBs are ~1.4+" diameter... of course full roll-cages, re-welding, etc.... and where they are intended to be driven... smooth road courses.... So, the 1.24 are pretty small, on that note.

FF will make the 1.24 TBs for anyone interested, or 1.22, or 1.20 (they already offer 1.18)... and for most Mopar ppl, if they eventually choose increasing the TB size and rate, they will find them to be one of the best overall improvements... BUT, its a "package" of other mods that have to follow... leafs, shocks, sway bars... bushings, steering box/wheel, driver's seat, vehicle weight reduction, weight balancing (side-to-side). Also, I'm certain that adding SFC, and re-welding the k-frame, adding a roll-bar/cage, etc., will help for the unibody's torsional rigidity... honestly, that's one thing I've never done (again, SCCA rules restrictions/limitations in the past classes that I've run)... Some of those rules have since changed, so, I'll probably eventually add welded-in SFC), also, I may even change the setup towards other club's class rules, etc -- but always following a "rule book" so that the mods are not done foolishly with wasted $$$ (so many items items out there offered by different companies, don't fit within certain club's allowable "rules", so, be careful!). The car is rust free and has survived extremely well throughout all of its competative years... and street/hwy driving, too! Its very enjoyable to drive anywhere, anytime.

Not sure if it would work or be practical..... But could you run t-bars and coil-overs to get the desired spring rate?