sway bar replace

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Also, if you have a rear sway bar that it is too large compared to the front you then transfer more of the lateral force to the rear axis which leads to oversteer. That said, I would prefer a little smaller than a little larger sway bar in the rear.

 
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Also, if you have a rear sway bar that it is too large compared to the front you then transfer more of the lateral force to the rear axis which leads to oversteer. That said, I would prefer a little smaller than a little larger sway bar in the rear.
I agree Tony, but I wish there was an in between size available to us, 1/2" too small, 7/8" to large.  In the NPD catalog, I notice that they list an ADDCO 3/4" rear sway bar #5A772-3A for 71-73's and a 2 position adjustable #5A772-1B (whatever that is), and it states to match a 1" front bar with a 3/4" rear bar, or a 1 1/8" front bar with a 7/8" rear for neutral handling, BUT then it lists #5A772-10A as a 7/8" OE style (which we now know is not) replacement, must be used if the car originally had a rear bar......

So, if ADDCO make a 3/4" bar, will it fit a car that had original rear sway bar or not? OR is it a retro fit that needs different mounts?

Hellwig list a 1" front and a 1 1/8", w/factory rear sway bar #5482-7D. They do not list rears for 71-73's

So from that one would have a 1 1/8" front with a 1/2" rear, Hmmmm!

The debate continues.

 
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I agree Tony, but I wish there was an in between size available to us, 1/2" too small, 7/8" to large.  In the NPD catalog, I notice that they list an ADDCO 3/4" rear sway bar #5A772-3A for 71-73's and a 2 position adjustable #5A772-1B (whatever that is), and it states to match a 1" front bar with a 3/4" rear bar, or a 1 1/8" front bar with a 7/8" rear for neutral handling, BUT then it lists #5A772-10A as a 7/8" OE style (which we now know is not) replacement, must be used if the car originally had a rear bar......

So, if ADDCO make a 3/4" bar, will it fit a car that had original rear sway bar or not? OR is it a retro fit that needs different mounts?

Hellwig list a 1" front and a 1 1/8", w/factory rear sway bar #5482-7D. They do not list rears for 71-73's

So from that one would have a 1 1/8" front with a 1/2" rear, Hmmmm!

The debate continues.
My comment is based on "theory". Technically speaking the correct setup can only be tested on the track unless the car is exactly as it came out of the factory. All these changes we have made over the years, such as tires, different springs, PUR bushings, traction bars, weight distribution, etc, will affect the whole balance. Unfortunately, very few people can afford track and development time. With sway bars is eventually more complicated beyond the diameter. The material stiffness play a role, the length of the bar's arms play a role and the type of bushings will play a role. A PUR bushing technically will increase the "apparent" diameter of the bar compared to rubber bushings because it makes the sway bar overall more stiff. The adjustments referred to for sway bars typically involve changing the effective length of the sway bar arms.

That said, it very well could be that a 7/8" sway bar works well with a car that has upgraded components/tires, but the only way to really know would be to test the 1/2" and the 7/8"  :whistling:

 
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My comment is based on "theory". Technically speaking the correct setup can only be tested on the track unless the car is exactly as it came out of the factory. All these changes we have made over the years, such as tires, different springs, PUR bushings, traction bars, weight distribution, etc, will affect the whole balance. Unfortunately, very few people can afford track and development time. With sway bars is eventually more complicated beyond the diameter. The material stiffness play a role, the length of the bar's arms play a role and the type of bushings will play a role. A PUR bushing technically will increase the "apparent" diameter of the bar compared to rubber bushings because it makes the sway bar overall more stiff. The adjustments referred to for sway bars typically involve changing the effective length of the sway bar arms.

That said, it very well could be that a 7/8" sway bar works well with a car that has upgraded components/tires, but the only way to really know would be to test the 1/2" and the 7/8"  :whistling:
Very well put Tony. I appreciate your input as usual. The unfortunate thing is it would be way too expensive to buy and test all the variables, but it sure as heck would be fun to do.

 
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Just to add... my car really does handle much better with the 7/8” bar. It was a very noticeable difference from the old wimpy 1/2 bar. Just wish they would have made it fit better to begin with. No difference with the re-designed bar other than now it fits better. 
So I have a 1 1/8” sway bar in the front with the 7/8 in the back. My car drives and corners very nice! Way better than before.

 
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Just to add... my car really does handle much better with the 7/8” bar. It was a very noticeable difference from the old wimpy 1/2 bar. Just wish they would have made it fit better to begin with. No difference with the re-designed bar other than now it fits better. 
So I have a 1 1/8” sway bar in the front with the 7/8 in the back. My car drives and corners very nice! Way better than before.
Awesome. What tires and suspension do you have?

 
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Just to add... my car really does handle much better with the 7/8” bar. It was a very noticeable difference from the old wimpy 1/2 bar. Just wish they would have made it fit better to begin with. No difference with the re-designed bar other than now it fits better. 
So I have a 1 1/8” sway bar in the front with the 7/8 in the back. My car drives and corners very nice! Way better than before.
Mine too. I love (carefully) carving the corners on my favorite road alongside the River Thames. Very little body roll now. Straight line driving is no real fun for me, other than putting the hammer down.

EDIT: just to add info, my fronts are magnum 500 (repops) 14 x 7 with BFG 235-60-R14 and rear 14 x 8's with 245-60-R14. rear springs just upgraded to EATON Boss 351 springs @ 153lbs spring rate and KYB Gas-A-Just shocks, which I may change to KYB low pressure ones to see which I like better.

 
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Did you check your buck tag to see if it shows competition suspension (CS)? It was an option on all cars except with the 6 cylinder. It may not have shown up on the Marti report. 
He has a Mach 1, they all came with Competition Suspension. His H-code didn't have a rear bar from the factory, but not hard to swap one in, did it on my first Mustang. 

 
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You guys need to sign up to watch Kenny Brown's cars and coffee on Saturdays. He removes to sway bar to improve handling. Hard to say he is crazy when he won 8 championships in Trans Am and built over 200 trans am competition cars. You can ask questions and have private one on one if you want. He is big into putting lots of spring in the car to keep it from leaning with shocks to keep control.
All of the previous Cars and Coffee are out there if you want to go back through them. Lots of free expert info.
It is not me saying this he does.

 
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You guys need to sign up to watch Kenny Brown's cars and coffee on Saturdays. He removes to sway bar to improve handling. Hard to say he is crazy when he won 8 championships in Trans Am and built over 200 trans am competition cars. You can ask questions and have private one on one if you want. He is big into putting lots of spring in the car to keep it from leaning with shocks to keep control.
All of the previous Cars and Coffee are out there if you want to go back through them. Lots of free expert info.
It is not me saying this he does.
I have heard similar from others. Charles Maier (https://www.maierracing.com/) recommends to use the Panhard bar without sway bar unless racing in a very sticky surface such as concrete where the grip is much better. What happens is the perception that less roll leads to better grip but that's not necessarily the case unless the whole package is right.

 
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Okay, I think we're just getting a bit off track here now. We're not building race cars or even high performance street cars. We are trying to get a 71-73 Mustang to handle a bit better without breaking the bank. Sure, we could spend 5 grand or more on a really slick suspension set-up and some indeed want to do that and build a truly amazing rocket ship, but that's not many of us. For sure, not too many of us really know the ins and outs of suspension geometry, so we sort of have to trust what's out there in the marketplace and hope that sufficient engineering was done prior to us buying the parts. 

jscott merely wants to know if a thicker diameter anti-sway bar would be a benefit over the 1/2" bar he thinks is on his car.

I'm not saying watching the videos and learning how to build and or set up a race car or wild street machine is a bad thing, far from it. I intend to check some of those out myself. Learning something new every day is a good thing.

 
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Not really off track the race cars have to use the factory parts yes they can change some but you cannot just put anything you want in a Trans Am car. Sway bar is factory way to try to compensate for wrong springs that will kill the ride that people want.
My understanding was that the main purpose of sway bars was to allow manufacturers to run softer springs for a nicer ride in street cars. You can soften the springs but in corners the sway bar would essentially increase the spring rate. So trying to balance and give you the best of both. But as we all know, jack of all trades=master of none. 

 
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