Torsion Bar Upgrade for '65 Barracuda Formula S

[66fs]

I'd leave your car alone, stock Formula S torsion bars and rear springs. They are sweet driving cars. Try what you have first, then if you want more, modify it. I'll second getting Bilstein shocks. They are worth the money if you can afford them.

 

[72bluNblu]

What do you mean by 0 arch or 1” arch? Is that zero or one inch above stock in terms of ride height? I just don’t want to make any assumptions. I know those springs are .5" longer in the front segment and you need a shorter front hanger to accommodate the length.

Do you or have you ever run these? I believe the spring rate is or was supposed to be 120lbs/inch which vs the the 150-160 pounds/inch on the ss springs may offer a much nicer ride? Also, do you know the eyelet size for the bushings and what size bushings etc fit?

I’m contemplating buying and trying these the PN 415 version and trying them with either the ar118 brackets or make my own front hanger brackets.

Yes, zero arch is factory height, 1” is plus one inch. They were oval track springs, so they were often run staggered because of a banked track.

The front segment is a 1/2” longer, but the overall spring length is the same, you do not run shorter front hangers with them. The wheels move about a 1/2” back, which typically centers them better in the wheel tub.

The spring rate is ~120 lb/in, which makes them stiffer than the original XHD springs (110 lb/in), but softer than the SS springs (160 lb/in). Typically handling cars are set up 120-130 lb/in for the rear springs, so stiffer than most standard factory springs but nowhere near as rough a ride as SS springs.

Front eyelet uses the 5/8 eye bolt, the rear uses a different shackle bushing than factory, I’ll have to look up the part number.

I have AFCO springs on my car that match the Mopar oval track spring specs- 1/2” longer front segment, 121 lb/in rate, zero arch. They discontinued that part # when Mopar started making the oval track springs again. I have a set of the Mopar oval tracks as well, but I haven’t run them. They’re made in Mexico and are not as good of quality as the AFCO’s. But last I checked AFCO still wasn’t making the 121 lb/in springs.

Honestly I wouldn’t mess with the Mopar oval track springs because of their hit and miss quality. I’d call @BergmanAutoCraft, he was having springs made to the 130 lb/in spec.

 

[4mulas]

Yes, zero arch is factory height, 1” is plus one inch. They were oval track springs, so they were often run staggered because of a banked track.

The front segment is a 1/2” longer, but the overall spring length is the same, you do not run shorter front hangers with them. The wheels move about a 1/2” back, which typically centers them better in the wheel tub.

The spring rate is ~120 lb/in, which makes them stiffer than the original XHD springs (110 lb/in), but softer than the SS springs (160 lb/in). Typically handling cars are set up 120-130 lb/in for the rear springs, so stiffer than most standard factory springs but nowhere near as rough a ride as SS springs.

Front eyelet uses the 5/8 eye bolt, the rear uses a different shackle bushing than factory, I’ll have to look up the part number.

I have AFCO springs on my car that match the Mopar oval track spring specs- 1/2” longer front segment, 121 lb/in rate, zero arch. They discontinued that part # when Mopar started making the oval track springs again. I have a set of the Mopar oval tracks as well, but I haven’t run them. They’re made in Mexico and are not as good of quality as the AFCO’s. But last I checked AFCO still wasn’t making the 121 lb/in springs.

Honestly I wouldn’t mess with the Mopar oval track springs because of their hit and miss quality. I’d call @BergmanAutoCraft, he was having springs made to the 130 lb/in spec.

Thanks, I’m in alberta and shipping and buying in usd is not fun, especially right now. I was looking at the afco unit you were using and noticed the lowest rate they offer now is 141lb -ish? (going from memory). The thing that tempts me about trying the mopar one is I can buy them in cdn dollars jobber through my contacts for a little less than half of what the afco’s list at….

I wonder why AR Engineering (Andy) lusts and sells the ar118 front hanger brackets? I was reading (incorrectly) that the spring was 1/2 longer overall with the extra inch on the front segment, but now I see it is the same length but has the locating pin 1/2’ further back. I guess his hanger would just pull the whole set up back to stock locations. Is it possible the diff gets too close to gas tanks and things or something?

I wish we had better spring selection up here for reasonable pricing like you guys have….

 

[72bluNblu]

Thanks, I’m in alberta and shipping and buying in usd is not fun, especially right now. I was looking at the afco unit you were using and noticed the lowest rate they offer now is 141lb -ish? (going from memory). The thing that tempts me about trying the mopar one is I can buy them in cdn dollars jobber through my contacts for a little less than half of what the afco’s list at….

I wonder why AR Engineering (Andy) lusts and sells the ar118 front hanger brackets? I was reading (incorrectly) that the spring was 1/2 longer overall with the extra inch on the front segment, but now I see it is the same length but has the locating pin 1/2’ further back. I guess his hanger would just pull the whole set up back to stock locations. Is it possible the diff gets too close to gas tanks and things or something?

I wish we had better spring selection up here for reasonable pricing like you guys have….

Yeah the closest thing AFCO sells now that I’m aware of is a 142 lb/in spring, a 20230 that has a 5 5/8” arch (zero) and a 20231 that has a 6 5/8” arch (+1”).

I wish the Mopar springs were decent, but I stopped recommending them because the quality was so hit and miss. The set I have isn’t as good as my AFCO’s, and other members got ones that looks worse than what I got. When they were decent quality it was a good low buck option. But MP started making them in Mexico, initially the quality wasn’t bad but I dunno if MP gave up quality checking or what but the quality fell off a cliff after a few years.

I don’t know why you’d run a shorter hanger with them, because you’d pull the rear shackle forward and upset that working angle because the overall spring length is the same. Unless you moved the shackle forward too. I ran my AFCO’s with 1/2” offset hangers and shackles for standard sprigs, the springs aren’t longer. I’ve since gone to sliders in the back instead of shackles but the front hangers are the same.

It does shift the rear axle back, but it’s not a full 1/2” because of the arch. Lots of drag racers used to space the hangers back anyway because it does center the wheel in the tub better so you can run a taller tire. The diff is closer to the gas tank but it’s not an interference issue.

 

[junkyardhero]

i ran the MP oval track springs in my 1st 65 dart. they were well matched to the 990 t-bars rate wise. the front sway bar was a 1.250" and i had a 9/16" rear bar. the combo was really well balanced and sure footed with out being too heavy or overbearing on the street. better shocks would've made it more livable though.

 

[Dave999]

i made my own interleaves

i found that my car came with just the plastic parts to sit at the end of the springs
yet high end US cars had zinc plates sandwiched between the springs as well, self lubricating.... etc etc

the kits available at the time used steel shim that had been galvanised instead of pure zinc, which were expensive per side and basically worthless the thin zinc coating comes off and they just rust up like the springs do....

i purchased some 0.9 MM zinc plate
cut it into strips the width of the spring
i put a hole 1 spring width in from one end of each strip
dismantled my spring pack
laid the zinc strips facing the front eye between each leaf forward to just before the clamp
new plastic bits were purchased
all clamped back together

all back in, standard clamps, silent operation, and the springs actually "spring" a difference you can feel....

higher end set up in a car that had "poverty" pack springs

simple cheap and effective upgrade

Dave

 

[4mulas]

Yes, zero arch is factory height, 1” is plus one inch. They were oval track springs, so they were often run staggered because of a banked track.

The front segment is a 1/2” longer, but the overall spring length is the same, you do not run shorter front hangers with them. The wheels move about a 1/2” back, which typically centers them better in the wheel tub.

The spring rate is ~120 lb/in, which makes them stiffer than the original XHD springs (110 lb/in), but softer than the SS springs (160 lb/in). Typically handling cars are set up 120-130 lb/in for the rear springs, so stiffer than most standard factory springs but nowhere near as rough a ride as SS springs.

Front eyelet uses the 5/8 eye bolt, the rear uses a different shackle bushing than factory, I’ll have to look up the part number.

I have AFCO springs on my car that match the Mopar oval track spring specs- 1/2” longer front segment, 121 lb/in rate, zero arch. They discontinued that part # when Mopar started making the oval track springs again. I have a set of the Mopar oval tracks as well, but I haven’t run them. They’re made in Mexico and are not as good of quality as the AFCO’s. But last I checked AFCO still wasn’t making the 121 lb/in springs.

Honestly I wouldn’t mess with the Mopar oval track springs because of their hit and miss quality. I’d call @BergmanAutoCraft, he was having springs made to the 130 lb/in spec.

I think I’m willing to officially try these as they cost me the equivalent of 75 usd on jobber account through my distributor. For the price of them I’m willing to see just how crap they are or hopefully aren’t. I’ll be a 2025 Guinea pig.

There are indeed the same over all length? I’m putting my car down off the jack stands tomorrow and if the wheel is reasonably centred in the opening I’m gonna try them.

I can’t believe people were making a shorter front hanger seeing as the spring is the same overall. Did you measure them yourself?.

 

[72bluNblu]

I think I’m willing to officially try these as they cost me the equivalent of 75 usd on jobber account through my distributor. For the price of them I’m willing to see just how crap they are or hopefully aren’t. I’ll be a 2025 Guinea pig.

There are indeed the same over all length? I’m putting my car down off the jack stands tomorrow and if the wheel is reasonably centred in the opening I’m gonna try them.

I can’t believe people were making a shorter front hanger seeing as the spring is the same overall. Did you measure them yourself?.

Brave man! But who knows, it’s definitely been a few years. And given that price point I definitely get it!

Yes, I measured both the AFCO’s I have on my Duster and the oval tracks I have as they both have the longer front section. They were pretty much the same, I don’t recall the exact measurements but I would definitely remember if they were a 1/2” different overall. And with the AFCO’s the shackle angle was correct, which is the more important part anyway.

 

[4mulas]

Brave man! But who knows, it’s definitely been a few years. And given that price point I definitely get it!

Yes, I measured both the AFCO’s I have on my Duster and the oval tracks I have as they both have the longer front section. They were pretty much the same, I don’t recall the exact measurements but I would definitely remember if they were a 1/2” different overall. And with the AFCO’s the shackle angle was correct, which is the more important part anyway.

Oh ****, now I’m second guessing. I forgot about pinion and shackle angle discrepancies. Maybe I won’t…. Waffler!

 

[72bluNblu]

Oh ****, now I’m second guessing. I forgot about pinion and shackle angle discrepancies. Maybe I won’t…. Waffler!

I wouldn’t worry about the overall dimensions personally. The quality of the spring itself is all I’d be concerned about.

The MP oval tracks have been around forever, and the AFCO’s that are made to oval track specs of varying spring rates have been around a long time too. They work just fine with standard hangers.

 

[4mulas]

I wouldn’t worry about the overall dimensions personally. The quality of the spring itself is all I’d be concerned about.

The MP oval tracks have been around forever, and the AFCO’s that are made to oval track specs of varying spring rates have been around a long time too. They work just fine with standard hangers.

I’ll give them a whirl. I wasted more money worse things. lol

 

[4mulas]

I wouldn’t worry about the overall dimensions personally. The quality of the spring itself is all I’d be concerned about.

The MP oval tracks have been around forever, and the AFCO’s that are made to oval track specs of varying spring rates have been around a long time too. They work just fine with standard hangers.

As you seem to know, the one thing I was going to ask but forgot until now is if there is actually a difference between left and right in ride height or pounds per inch spring rate etc…. On the oval track springs.
Ie: do I need to order two from the drivers side etc, as I would if I used SS springs to avoid A - excessive ride height, and B - uneven height from side to side.
Thanks in advance for your reply.

 

[72bluNblu]

As you seem to know, the one thing I was going to ask but forgot until now is if there is actually a difference between left and right in ride height or pounds per inch spring rate etc…. On the oval track springs.
Ie: do I need to order two from the drivers side etc, as I would if I used SS springs to avoid A - excessive ride height, and B - uneven height from side to side.
Thanks in advance for your reply.

The spring rate is the same, number of leafs is the same. The P4529414 is a 0 arch spring, the P4529415 is a +1” spring. If you want the car to sit level you need both springs to have the same part #.