Big Block Suspension Question

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67BBCuda

67BBCuda

'67 Barracuda Fastback
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In the very early stages of resto right now, putting new brakes in to get it road safe.

But in doing the brakes, the suspension might as well be changed. We plan on doing a 440 swap down the road. On a scale of "almost useless" to "absolutely necessary", where does changing the torsion bar suspension to a coil over conversion lie?

For information, it's a 67 Barracuda that will be almost exclusively street driven, with occasional track days.

Thanks in advance.
 
On the far side of not. Look at PST and get 1.12 or larger Torsion bars for heavy road (twisty) driving or 1.03 or so for street / drag racing. New bars are a few hundred bucks, coil over setup is 3-5 grand… you’ll never get the money out of the car you put into it. Cars are like boats, Bust Out Another Thousand. So to each their own, do what you want
 
My first question to you would be what do you hope to gain by changing to coilovers? There's nothing wrong with torsion bars- just get some nice fat ones, over 1", and a decent anti-sway bar. The only thing to be gained in your instance by coilovers would be a bit more room for header clearance. Not worth the investment, IMO.
 
67BBCuda said:
In the very early stages of resto right now, putting new brakes in to get it road safe.

But in doing the brakes, the suspension might as well be changed. We plan on doing a 440 swap down the road. On a scale of "almost useless" to "absolutely necessary", where does changing the torsion bar suspension to a coil over conversion lie?

For information, it's a 67 Barracuda that will be almost exclusively street driven, with occasional track days.

Thanks in advance.
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“almost useless”

From a suspension standpoint it’s completely unnecessary, you can get the torsion bar suspension to do whatever you want the coilovers to do. There are some minor pros/cons but it’s basically a wash IMHO.

The advantage to the coilover conversion is the rack and pinion steering, which some people prefer (but doesn’t make you any faster) and the header clearance. Not sure how frequently you pull your engine or headers, but you can install the headers with the torsion bars faster and cheaper than you can install a full on coilover conversion.

And you can fully rebuild and completely upgrade your torsion bar suspension for quite a bit less than a conversion.
 
Professor Fate said:
My first question to you would be what do you hope to gain by changing to coilovers? There's nothing wrong with torsion bars- just get some nice fat ones, over 1", and a decent anti-sway bar. The only thing to be gained in your instance by coilovers would be a bit more room for header clearance. Not worth the investment, IMO.
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Very big weight difference with a complete tubular K-member with a rack and coil overs would be the magor gain. I went with AJE for a light weight drag car. HDK would be the prefered dual purpose due to strength. My street Demon will be all factory suspension. Remember the stiffer the bars the more push you'll have in turns. You need to transfer weight to the outside on entry and exit . The weaker the bar the looser the car will be.
 
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..........And for the street, even a weak kneed DD, an anti sway bar is a NECESSITY........

A bar effectively makes weaker T bars stronger, so to say, as it helps level the thing in turns
 
After using an alterkation i'd never build another one without it.
 
Scody21 said:
On the far side of not. Look at PST and get 1.12 or larger Torsion bars for heavy road (twisty) driving or 1.03 or so for street / drag racing. New bars are a few hundred bucks, coil over setup is 3-5 grand… you’ll never get the money out of the car you put into it. Cars are like boats, Bust Out Another Thousand. So to each their own, do what you want
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I've been looking at PST for the last couple of days, and that seems like the most realistic option for me. Thanks!
 
Professor Fate said:
My first question to you would be what do you hope to gain by changing to coilovers? There's nothing wrong with torsion bars- just get some nice fat ones, over 1", and a decent anti-sway bar. The only thing to be gained in your instance by coilovers would be a bit more room for header clearance. Not worth the investment, IMO.
Click to expand...

I can still get headers installed, they just will be more restricted in what they can do, right?
 
67BBCuda said:
On a scale of "almost useless" to "absolutely necessary", where does changing the torsion bar suspension to a coil over conversion lie?
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not needed.. if mostly street driven just put larger torsion bars (1"+) and a sway bar along with a quality shock and be done with it..

that being said. an alter-k-tion is awesome up front.. nothing feels like that r&p steering and man the room under there for headers is second to none..
 
I have a 440 in my Duster with PST 1.03 torsion bars combined with a QA1 kmember/suspension. I love them. And if I had coil overs, they’d hit the insides of my front wheels.
So I’d never do a coil over conversion (in the front).
 
Craig Burriss said:
I have a 440 in my Duster with PST 1.03 torsion bars combined with a QA1 kmember/suspension. I love them. And if I had coil overs, they’d hit the insides of my front wheels.
So I’d never do a coil over conversion (in the front).
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I'm on the fence about doing tubular kmember, but I'm feeling like keeping the kmember stock is the way to go for me. Any big benefit other than weight savings?
 
67BBCuda said:
I'm on the fence about doing tubular kmember, but I'm feeling like keeping the kmember stock is the way to go for me. Any big benefit other than weight savings?
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The weight savings aren’t that much. It is much stiffer and stronger than a factory kmember though. If my original kmember wasn’t rotted out, I probably would’ve just reinforced it.
 
roccodart440 said:
After using an alterkation i'd never build another one without it.
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I can't remember, have you run a QA1 K member before the alterkation?

My plans call for the QA1 front end setup with torsion bars. I want to keep my cg as low as possible and torsion bars help with that.
 
Thanks for everyone's responses! It looks like I'm going to go with upgrading the torsion bars and other suspension items and deal with any clearance issues when I get there.
 
I figure if Hotchkis can make a 4 door Satellite faster than an (admittedly stock) BMW on a Track (with the guy that drives that BMW on that track to test tires) then the Torsion Bar suspension can't be all that bad.
That said, of course there's the header clearance, weight, & easier? tuneability differences.
I'm shooting for the look of surprise when I whip up on some corners then tell somebody its 1968 Mopar suspension technology.
 
67BBCuda said:
I'm on the fence about doing tubular kmember, but I'm feeling like keeping the kmember stock is the way to go for me. Any big benefit other than weight savings?
Click to expand...

If you are going to a BB, that QA1 K Member doesn't technically bolt right in. You would need conversion biscuit mounts to go from a SB to a BB.

I run a BB with QA1 upper arms, lower arms and strut rods along with Bilstein RCD shocks and PST 1.02" bars. It is a firm ride, but I have no complaints, so much better than the stock setup that I had. I just ordered a Hellwig sway bar to install as well, we'll see how much that helps too. Out back I have modified B Body SS springs that are inboarded for a mini tub with the same RCD Bilsteins. I want to do something with the springs, but not sure what, it rides good, but could use something a little firmer, maybe a rear sway bar as well.
 
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