hemi torsion bars?

i have a 65 coronet, w/small block want to put better suspension, are the hemi bars too much? for daily driving, are poly bushing too noisy?

Bigger bars are going to make it ride firmer. How much firmer are you ok with? For my 65, I got the 1.06 dia bars from Firm Feel along with rear springs, Bilstein shocks all around, front and rear sway bars, upper control arms, adjustable strut rods, 9/16" tie rods w sleeves plus some other stuff. I got a $3k tee shirt from them and they gave me the suspension stuff for free. LOL! My intentions for the car are track events, auto crossing, some drags, fun curvy road driving etc. Its also getting quite a few structural upgrades too. Frame connectors, torque boxes etc. Poly bushings can squeak. I have no problem with my car riding stiff when I get it done. My daily driver is am 04 Dodge 3500 Cummins dually so I'm used to being in something that doesn't ride like a Caddy. What are you willing to put up with?

The factory Hemi TBs are still relatively weak by today's standards. They are not overly stiff at all. Consider at least about a 1.12 for notable improvement.

I've run many different diameters... settled on 1.24" (largest that will fit inside the hex opening... still not bad for street/highway... just avoid potholes and go slow over train tracks. My Challenger is setup for national level competition AX, HSAX, HPDE... and driven to/from the events.

Hemi bars will be a big improvement from what you have today. If you have the bars go ahead and put them in and drive it to see what you think. If you don't have the bars then you might want to go even thicker. For a daily driver street car I'd probably put the 0.960 bars in there if you can find them or go one size bigger. Once you get over 1 inch you'll want to invest in a very good quality shock absorber such as Koni or Bilstein. Do not use cheap shocks with big bars. Your teeth will fall out when you hit a bump.

Bottom line, anything you install bigger will be liked. The only problem then will be, deciding if you went big enough.

I agree with JCC. When I went to 300# bars from the factory 140#ish bars I didn't think it was too harsh at all and actually wished I went bigger. I did match the bars with a quality shock at the same time. The ride only went to pot when I went I put on 18" wheels. Keep 15" with plenty of sidewall and it'll be fine.

I daily drive a '73 Dodge Dart with 1.08" torsionbars from Sway-A-Way and 2-way adjustable Viking shocks.
Not 'harsh' at all. Just firm and just enough control for daily usage.

I would go to 1.12" in B-body without any consideration.


The fear of going bigger, is bigger then the change to bigger itself...

So Mitch, be interesting to hear your opinion here or anybody else in the 1.24" TB club.. What is your tire/wheel package with the above 1.24 TB's?

I have always been a proponent of big TB's since first joined this site, and so have you if I remember correctly.

I'm making a number of mods to my SB ebody with some aero DF, and keeping a TB IFS is important for me. I'm going with a C body TB size set-up, going to 30 series tire and 19x12"W rim, custom longer LCA, and UCA, and whatever size sway bar works.

Car will see 90% track time, on a bumpy track (Sebring).

The C body TB hex (Ebody length) will allow approx 1.4" Dia TB max. It will be whatever I decide. I'm likely going with a hollow bar to keep weight down, and not get excessive wheel rates.

So my question, with your wheel/tire package, how do you like your current TB ratings? Sounds like a stiffer TB would be at least tried, if it was possible for you ( which is not with your current ebody hex). Do bumpy tracks have any major downsides with your 1.24's? I can calculate your current TB wheel ratings if most of the set up is stock, and wheel offset is close. I'm starting from scratch almost and wondering how much stiffer my target might/should be.

No matter what, everything will be run thru "Performance Trends" for additional consideration.

JCC -- I have different setups in tires for different occasions, however, the one that matters most to me is is for when I'm running the car at a track event -- pylon AX or HPDER/HSAX. Street driving is minimal for me... I used to trailer it when I was running national SCCA AX events in the 80s-90s... took a ~10 year break (family) in the early 2000s and sold the trailer... back now driving to/from events... no problem... just avoid the pot holes and go slow over any train tracks. etc.

Adjust the tire PSI for street/hwy driving for a little better comfort... say, about 28-30 front and about 26-28 rear. Then, at the track events (AX or HPDE/HSAX), increase about 5-10 pounds and determine if any more or less is needed for competition throughout the day.

I've also played a lot with the adjustable red Konis... settled full-stiff front, ~2/3 stiff rear. Recently changed to QA1 double adjust fronts and have them set at 50/50... will play more as time allows.... then also will change to double-adjust rears.

Typically, most track events are smooth. A big concern I've learned is that the stiffer front TBs help deter lift and dive... both that is not wanted for better handling.

Don't forget to run stiffer and flatter rear leafs, as well as stiffer rear shocks.

Use the sway bars as tuning devices.. and play infinitely with the bushings to ultimately fine-tune the sway bars.

Be certain to have the weight balanced... diagonally should be 50/50 for best handling.

NOTE: Installing C-body hexes so to install larger TBs is an option, but I doubt if I'll ever go that route... my setup works great as-is. The driver and better tires are what's most needed for further improvement. Also, observing sanctioned club racing rules for allowable car modifications is a critical decision factor.

1st. how much chassis travel do you have ? then you can make the proper choice for springs..... you need to be as soft as you can without using all your [chassis] limit of travel. you can use shock travel indicators to get the info. getting into the corner is -everything-- you will do better to rate your springs by lbs. per inch of compression. find out what you have now and with the shock travel info you can see where to go.

Thanks Mitch, all good basic tips. My takeaway for my application, I can go stiffer than the 1.25" rates, but I should be conservative in doing so.
With 30 series tires, I don't have a lot TP variance on the street.

Be curious how your new shock package works out for you, both in results and efforts it takes to get there.

FWIW, a maximum sized (1.41") C body TB in E/B body length has an effective rate of approx 790lbs/ft.
A solid max sized 1.25" TB in E/B length has approx rate of 484lbs/Ft.
A hollow C sized hex in E/B body length, outside 1.375"D, and .875"D center hole has approx rate of 593lbs/ft.
I'm likely on my project going slightly under 1.375" Outside Dia.

Wheel/motion rates are variable per application.

keep in mind when you change the length of control arms it will change the effective rate of the springs... like the changing of the location of the shocks will change their effect...

Yes, but those changes can be pretty minimal.

I've never calculated control arm length changes but I did calculate spring relocation changes and it came out to around 10# per inch of change in my B body and E body, provided I retained the splayed arrangement. Changing a splayed mount to parallel mount will also have an impact, although its change would obviously be smaller with the smaller movement of the housing mounting pin.