Sway bar recommendation

[runningman]

My 68 is currently in the resto shop.  I installed all the XV/US Car Tool stiffening components (torque boxes, core support, frame ties, inner fender braces) also did the K frame reinforcement and the LCA stiffening plates.  I'm piecing together all the suspension stuff and want to know what everyone recommends for sway bars.  Hotchkis currently has 25% off until 12/2 and was thinking about using theirs.  Does the front bolt into the stock locations?  I'm assuming all rear bars will need some drilling into the frame?  Thanks!

[Kern Dog]

The Hotchkis stuff is good but is not cheap. Helwig makes some good stuff at a cheaper cost.
Hotchkis uses hollow front sway bars in a 1 1/4" diameter. Maybe larger ? They do not specify what it compares to in a solid bar. The theory is that most of the strength in the sway bar is related to the outer diameter, not the center but I'd want to hear from an actual engineer on that.
Would a 1 1/4" bar with a 3/8" wall thickness, 3/4" wall overall with a 1/2" hollow space in the middle be as stiff as a 1 inch bar? 1 1/8" bar?
Firm Feel makes solid 1 1/4" bars. Their rear bars are frame hung, as are Hotchkis'. The Hotchkis rear bar mounts strangely though.

[runningman]

The Hotchkis stuff os good but is not cheap. Helwig makes some good stuff at a cheaper cost.
Hotchkis uses hollow front sway bars in a 1 1/4" diameter. They do not specify what it compares to in a solid bar. The theory is that most of the strength in the sway bar is related to the outer diameter, not the center but I'd want to hear from an actual engineer on that.
Would a 1 1/4" bar with a 3/8" wall thickness, 3/4" wall overall with a 1/2" hollow space in the middle be as stiff as a 1 inch bar? 1 1/8" bar?
Firm Feel makes solid 1 1/4" bars. Their rear bars are frame hung, as are Hotchkis'. The Hotchkis rear bar mounts strangely though.

Thanks Kern Dog!  So if they were all priced equal which would you choose?  The Hotchkis seem about evenly priced after the 25% discount

[garner7555]

The Hotchkis stuff os good but is not cheap. Helwig makes some good stuff at a cheaper cost.
Hotchkis uses hollow front sway bars in a 1 1/4" diameter. They do not specify what it compares to in a solid bar. The theory is that most of the strength in the sway bar is related to the outer diameter, not the center but I'd want to hear from an actual engineer on that.
Would a 1 1/4" bar with a 3/8" wall thickness, 3/4" wall overall with a 1/2" hollow space in the middle be as stiff as a 1 inch bar? 1 1/8" bar?
Firm Feel makes solid 1 1/4" bars. Their rear bars are frame hung, as are Hotchkis'. The Hotchkis rear bar mounts strangely though.

I get what you are saying, but the one made from tubing is drastically more stiff.  I have a background in steel fabrication and I can attest to the fact that tubing is more "stiff" than solid bar.  That is a good question Kern Dog, it sort of defies logic in some ways.  Some people don't even think about it enough to ponder on that question.   

I am running QA1 for my front sway bar but it will not work with the factory K frame.  It is 1.25" tube and my rear bar is a 7/8" solid bar.  My car corners very flat and I am happy with it.   

[Kern Dog]

If it can be proven that the hollow/tubular bar is stiffer, it would be a great thing. The weight savings is a nice feature.
I do like the look of the Hotchkis stuff and I want to support American made parts.
I have never owned anything made by Hotchkis but the owners I've spoken to are satisfied. Same goes with Hellwig and Firm Feel though.

[runningman]

Came across this while researching  https://youtu.be/nxS4l31p5V4

[runningman]

The Hotchkis stuff os good but is not cheap. Helwig makes some good stuff at a cheaper cost.
Hotchkis uses hollow front sway bars in a 1 1/4" diameter. They do not specify what it compares to in a solid bar. The theory is that most of the strength in the sway bar is related to the outer diameter, not the center but I'd want to hear from an actual engineer on that.
Would a 1 1/4" bar with a 3/8" wall thickness, 3/4" wall overall with a 1/2" hollow space in the middle be as stiff as a 1 inch bar? 1 1/8" bar?
Firm Feel makes solid 1 1/4" bars. Their rear bars are frame hung, as are Hotchkis'. The Hotchkis rear bar mounts strangely though.

I get what you are saying, but the one made from tubing is drastically more stiff.  I have a background in steel fabrication and I can attest to the fact that tubing is more "stiff" than solid bar.  That is a good question Kern Dog, it sort of defies logic in some ways.  Some people don't even think about it enough to ponder on that question.   

I am running QA1 for my front sway bar but it will not work with the factory K frame.  It is 1.25" tube and my rear bar is a 7/8" solid bar.  My car corners very flat and I am happy with it.   

[Kern Dog]

Came across this while researching  https://youtu.be/nxS4l31p5V4

Hmmm, no shit, huh? That is great. Son of a beeeech!
Now I am curious. If I could swap something like this in that is stiffer and actually lighter, that would be great !
I love learning new things.

[Kern Dog]

Thanks Kern Dog!  So if they were all priced equal which would you choose?  The Hotchkis seem about evenly priced after the 25% discount

You are welcome. I love to see other Mopar guys building cars to handle well.
I took a different path with mine though. I modified a 1 1/4" solid sway bar from an '84 Chevy 1 ton 2wd truck. For the rear, I used a 3/4"bar from an '83 Imperial. I had to make mounts for the rear but I like doing that stuff. The store bought stuff looks nicer and bolts right in. I can see the appeal of that.
In the early 80s, GM started using hollow sway bars in the IROC Z28s and Trans Ams. They may have used them in other cars too. Weight savings is certainly important to new car manufacturers.

[b5blue]

  I used an ADDCO rear sway bar with stock up front. With the LCA plates added I used solid adjustable strut rods. Standard Monro-matic shocks, Mopar H.D. leaf springs and T-bars set at about stock ride height. The car rides nice not harsh, clears pot holes speed bumps deep puddles and is less tippy in the corners.
  Dropping the car with 2" lowering spindles and correct brackets out back could be the greatest handling gains without huge money I suspect. (All of my stuff was low dough daily driver stuff.) 

[runningman]

Thanks Kern Dog!  So if they were all priced equal which would you choose?  The Hotchkis seem about evenly priced after the 25% discount

You are welcome. I love to see other Mopar guys building cars to handle well.
I took a different path with mine though. I modified a 1 1/4" solid sway bar from an '84 Chevy 1 ton 2wd truck. For the rear, I used a 3/4"bar from an '83 Imperial. I had to make mounts for the rear but I like doing that stuff. The store bought stuff looks nicer and bolts right in. I can see the appeal of that.
In the early 80s, GM started using hollow sway bars in the IROC Z28s and Trans Ams. They may have used them in other cars too. Weight savings is certainly important to new car manufacturers.

That's awesome, I've been reading about people customizing sway bars to use on their Mopars.  Time is factor for me also, I work a bunch so not much time to mess around although I do enjoy that stuff.  I think I'm going with Hellwig, they offer a tubular bar also and currently have a $35 rebate until the end of the year!  Thanks again!  Matt

[runningman]

  I used an ADDCO rear sway bar with stock up front. With the LCA plates added I used solid adjustable strut rods. Standard Monro-matic shocks, Mopar H.D. leaf springs and T-bars set at about stock ride height. The car rides nice not harsh, clears pot holes speed bumps deep puddles and is less tippy in the corners.
  Dropping the car with 2" lowering spindles and correct brackets out back could be the greatest handling gains without huge money I suspect. (All of my stuff was low dough daily driver stuff.) 

You know it's been forever since I actually drove mine, I don't even remember what it was like lol.  I just want to have everything covered once it's done and not have to mess with it too much.  I do have the HD Mopar leafs and larger T-bars but I can't remember what diameter they are, I'll have to look.  I need to see what shocks I have also, I bought some off a member here years ago and they are still in the box.

[XH29N0G]

I have a related question.  Has anyone put up something like a proven engine combo, but a proven suspension combo, that people could look to in order to decide on various parts and how they match with tires, etc...    So what tires, to run with what parts to do what? is what I am looking for. 

If not, would you or others who have done this, be willing to put something like this on the Forum?

Everything I have done with the advice of folks here has helped, but what I do not know is whether even better suggestions could be made by looking at combinations.

[runningman]

I have a related question.  Has anyone put up something like a proven engine combo, but a proven suspension combo, that people could look to in order to decide on various parts and how they match with tires, etc...    So what tires, to run with what parts to do what? is what I am looking for. 

If not, would you or others who have done this, be willing to put something like this on the Forum?

Everything I have done with the advice of folks here has helped, but what I do not know is whether even better suggestions could be made by looking at combinations.

Excellent idea!  I would definitely be interested in this

[Kern Dog]

I think that Hotchkis is doing this with what they call their TVS (Total Vehicle System) kit. It has matched torsion bars, leaf springs, sway bars and a bunch of other things. I don't know how they differentiate between an all iron big block and an aluminum headed small block in terms of spring rates but it is a start.

[Jonas_N]

Ive got the hotchkis front and back, back bolts in very nice as it goes towards the rear.
The front one did bolt into the original location(Plus some extra welding) ...though it seems to be quite close to the LCF. Maybe I did something wrong.

[XH29N0G]

I think that Hotchkis is doing this with what they call their TVS (Total Vehicle System) kit. It has matched torsion bars, leaf springs, sway bars and a bunch of other things. I don't know how they differentiate between an all iron big block and an aluminum headed small block in terms of spring rates but it is a start.

Thanks. 

Now the trick is asking them about pairing tires/wheels, but that is a phone call away. 

[Kern Dog]

Yeah, good point.
There are some that argue that it is common to "Over-tire" a car. A guy at Moparts was going on about it, as if running a smaller tire was likely to make for better cornering performance. If this is true, chalk it up to yet another principle of engineering that seems to defy logic....like a hollow sway bar that is stiffer than a solid one!

I have a 295-45 rear tire and a 275-40 front. I picked the size to fill the wheelwell but I also need a wide tire for traction. I've always loved the NASCAR look with wide tires at all corners. The skinny front tire drag race look never appealed to me.

[b5blue]

There's real good info in the "Mopar Performance Chassis and Handling Book". Understanding the arc of component travel and changing engineered designs or values can have weird effects.   

[303 Mopar]

I have the Firm Feel 1 1/8" front bar and Hotchkis rear and would highly recommend them. The Firm Feel stage III steering box made a big difference as well.  I've had good luck with Bilstein shocks and have ran them on a couple of cars now. 

I put on black steelies last summer with 235/60 and 275/60. I also have MT 26x10 and 28x10 with Weld wheels. Both seems to do well around town.

[TexasStroker]

Proven Suspension Thread would be a nice addition.

Stated Purpose: Drag, Track, SCCA, Road Race, etc.  Could even add in Pro-Touring, Daily Driver, and Comfort Cruiser.  Everyone wants something different and a lot of times people wind up with good, but mismatched parts (just like when building an engine)...Taking a built car, showing what it does and how it performs, and then listing out what components got it to that point would no doubt be helpful to people as opposed to scouring the forum for multiple threads.

[Kern Dog]

When I owned a '76 Camaro, there were several companies selling stuff for the 70-81 Camaro and Firebird. There were different theories, different styles to choose from. Some were on the side of stiff springs and small sway bars, some were the opposite where they used stock spring rates and HUGE sway bars.
I think that somewhere in the middle of that is a good way to go. You can have a decent ride that doesn't rattle the car apart and still hold the road well.
I like wide, low profile tires. I also don't drive more than 1000 miles a year. Because of that, I went with sticky, soft compound tires that hopefully wont be at 80 % tread when I have to replace them due to age!

[runningman]

Thanks for all the info!!!  So I ended up ordering the Hellwig 1 3/8 tubular front and 7/8 solid rear from SDTruckSprings.com They have an extra 10% off currently and also qualifies for the $35 rebate for each bar so came to 488 shipped before rebates plus paid via PayPal with my Chase Freedom card so I believe I get an extra 5% cash back, not too bad!

[Kern Dog]

Just my opinion, but....That 7/8 bar may be too much for the rear. May be.
I had a setup with a 1 1/4" solid front bar and a 7/8" rear bar and the car was way too easy to spin. It would have made a great drift car because the ass end was always ready to come around. That is fun if there is nobody around, no trees, no telephone poles, no people....but otherwise it is not a great way to set up a car.
I had 1" torsion bars and Mopar performance HD leaf springs at the time.
Now I have the same front bar, 1.15 torsion bars, same leaf springs and a 3/4" rear bar. In short, I reduced the rear roll stiffness and added some to the front to shift the "ratio". It is neutral now. I can crank the wheel in a turn and the car just sticks. If I nudge the throttle, the ass end will bring in some oversteer but now it is on demand, not automatic.
There are many other factors that can affect the sway bar rate. Longer lever arms, bushing type, space between mounts, etc. Just be aware that in some cases, it is easy to go too far with sizing. Good luck.

[runningman]

SONOFABITCH, ok I guess I'll have to wait and see how it feels.  That's the only size rear that Hellwig offers I believe so I just went with it.  It'll be awhile before my car is painted so maybe next summer I'll finally be able to drive it 

[Kern Dog]

Well....
If the Hotchkis video is correct and the 1 3/8" hollow bar is stiffer than the 1 1/4" solid, you may be okay. It really does come down to the balance of front and rear roll stiffness. Stiff leaf springs and a big rear bar on a car with stock torsion bars and front sway bar is a bad choice because it is highly likely to over steer heavily. Conversely, soft stock leafs, no rear bar BUT huge torsion bars and a giant front sway bar will understeer like a 60's Dodge truck on ice.
It took me awhile to find a combination that felt right but then...I did things my own way on the cheap. The front bar is a modified bar from an '84 Chevy truck. The rear is from an '83 Imperial. I have maybe $100 in both bars including the bushings!

[67tbird]

Well....
If the Hotchkis video is correct and the 1 3/8" hollow bar is stiffer than the 1 1/4" solid, you may be okay. It really does come down to the balance of front and rear roll stiffness. Stiff leaf springs and a big rear bar on a car with stock torsion bars and front sway bar is a bad choice because it is highly likely to over steer heavily. Conversely, soft stock leafs, no rear bar BUT huge torsion bars and a giant front sway bar will understeer like a 60's Dodge truck on ice.
It took me awhile to find a combination that felt right but then...I did things my own way on the cheap. The front bar is a modified bar from an '84 Chevy truck. The rear is from an '83 Imperial. I have maybe $100 in both bars including the bushings!

I was wondering if you had drilled and tapped the zerk fittings on your front bar Kern Dog? I was thinking of doing that and using my rotozip to create a trough to retain the grease.

[Kern Dog]

The bar isn't drillled but the bushing and bracket are. The bushing has a recess in it to allow the grease to spread around the bar.

[HPP]

Much like a tubular bar can be stiffer than a solid bar, the rear bar size is another area of "it depends" comes into play. Many of the after market, larger than stock, under axles bars are comparable applied rates to the OEM frame hung bar. The reason being in that overall width, mounting points, arm length, and where the arms mount all have an impact on the rate the bar applies to the tires. Which is another important point, even the rate of something may not be what the tire actually sees because of its mounting.

For proven handling combos, Hotchkis obviously has it dialed in. Similarly, Firm Feel has been building handling mopars for longer than some guys have been building mopars. A call and talk to them can get you dailed into exactly what your car needs, however, you have to TALK to them about it. It is not a catalog package you simply order.

The Mopar Chassis Book has much information on drag set ups. Their street and performance handling formulas are actually a bit soft by modern standards. The Mopar Oval Track  book does have much more information on range of suspension set ups for handling applications, once you cipher through it. It is not a book that simply says buy this and match it to that because it is built on percentages that can be achieved multiple ways depending on track, car, and weights.  You will need to know front/rear weight bias or better yet, four corner weights. But when it comes down to it, there is no more voodoo to building hot suspensions than their is to building hot engines. Its just not as widely understood.

[b5blue]

With fairly fresh M.P. R/T T-bars and rear springs the Addco rear sway bar showed to have an old Mopar Performance part number. That told me it had a M.P. stamp of approval and at such a low cost was a no brainer. Again if I was going to track race I'd build a Triumph TR not an Mopar R/T anyway.