leaf spring vs 4link suspension F-body

[Shotaro]

I want to know the difference.

[cornfedbill]

The leaf spring set-up is very simple and provides good performance. All the Tran Am F-bodies ran leaf springs in the early days. For a daily driver that sees occasional track events or autocross, leaf springs are the way to go.

They will wrap with high torque. They also deflect laterally with high cornering loads. If you are running over 500 lb-ft of torque and are cornering near 1 g, the four link may show noticeable benefits.

A four link is more adjustable and can be lighter weight. It is more work to adapt it to an early F-body.

That said, I am putting a 3-link in my Nova. Not really because I have tons of torque, but because I wanted to trim some weight and make it more adjustable. It is overkill and way more work than is justified. I just want it.

I will likely never exceed the performance capability of good leaf springs with spherical bearings in the front eyes (which I have collecting dust on my shelf).

[BMR Sales]

there are definitely differences but it comes down to goals & budget for the car owner.

Leaf Springs are old technology that still works on Trucks. For someone keeping their car stock, leafs are just fine. As Bill was alluding to when you up the Horsepower & Torque, you would put a Leaf into Spring Wrap under acceleration and braking. Also the rear end will move side to side, which is improved on some cars with a Panhard Rod.

the Advantages to a Link/Torque Arm set-up;

- Adjustability – Every Component is adjustable – Pinion Angle, Watts Link, etc
- Increased Spring Control – Eliminates Leaf Springs & Axle Wrap

Articulation gives Bind-Free handling
Improves Straight Line Traction
Great for Street, Drag Strip, Road Course or A/X without compromising any Application.
- Watts Link – superior way to laterally locate rearend
- Ride Height – several adjustments with the Kit & Coilovers to adjust Stance
- Ride Control - Coilovers give Hundreds of options in Compression & Rebound
- Anti-Squat – lower control arms provide adjustment w/o changing Wheelbase

[79T/Aman]

depends on what you want to do with the car, and as Bill said depends on power as well, butt we have customers with up to 900+ HP
The one thing I would say is ignore those that say leaf springs are for horse and buggy, nonsense!! our leaf spring equipped customers have won 7 SCCA cam-T championships.
4 links have the blink and form advantage but the amount of weight saved is negligible only about 20lbs.
by form I mean easier ride height adjustment pinion angle adjustment (on some) but you must be aware of the collateral changes that it makes such as rear roll center, instant center, anti squat, rear roll steer, all this is why most will not see improvements in performance in a "bolt in" package and some will see negative results due to focusing on form over function.
The other benefits are reduce wrap up, depending on the bushings and how solid the mounting points are also remember that link suspensions also can suffer from wheel hop.
On some applications a little bigger tire may be able to be fitted with links and if there is any performance improvements it usually is due to the better tire.

A good leaf spring set up is mostly a set it and forget it, installation is quick, painless and economical, ride height adjustments are more involved as is pinion angle changes but leaf springs don't suffer from roll steer problems and adjusting ride height or pinion angle does not affect the roll center nearly as much.

[dontlifttoshift]

The only thing leaf springs do better than a link type suspension is save money.

[cornfedbill]

The only thing leaf springs do better than a link type suspension is save money.

And save a lot of time and complexity installing them. I think we dismiss leaf spring rear suspensions too quickly.

Mary Pozzi ran successfully with leaf springs for a long time, and did not change until she went to a full IRS. I would hope for $12k that IRS is better than leaf springs.

Many races have been won on leaf springs.

[dontlifttoshift]

Time is money, it was inferred but not stated clearly. So leaf springs do two things better than a link suspension. Save time. Save money.

Pretty sure there was 3 link in between the leaf springs and the IRS. Mary was successful in spite of the leaf springs, not because of them, otherwise they would still be on that car.

Sure, many races have been won with carburetors, too.

[Steve Chryssos]

To be crystal clear: Leaf springs are a compromise because they must both locate/articulate the axle, as well as support the weight of the vehicle. Conversely, Link type suspension divides up the two functions. Links locate and articulate the axle. Springs separately support the vehicle. Shocks serve the same purpose in both suspension types.

Leaf Springs: Locate and Support

Link type: Isolated functions. Each part of the system is free to do its job without compromise.
-- Links: Locate and Articulate Axle. The length of the links remains unchanged
-- Springs: Support and oppose compression forces

(Yes I am dumbing down the term "support" from a Physics standpoint.)

[79T/Aman]

Leaf spring can be made to articulate well, especially considering that performance suspensions don't move that much as compared to a stock vehicle.
Link suspension also has more moving points and migrating points that affect the geometry as the suspension is put in motion.

Links may remain the same length but they move at different arcs. On a leaf spring you can argue that the link (forward half of the leaf) changes length under hard acceleration, but that can be addressed, only the rear section of the leaf (spring portion) changes length that is accommodated by the shackle.

The bottom line is EVERY suspension system is a compromise, it all comes down to how much do you want to spend?, how much fabrication? what compromises from each system are you willing to overlook and/or able to work around.

[cornfedbill]

The bottom line is EVERY suspension system is a compromise, it all comes down to how much do you want to spend?, how much fabrication? what compromises from each system are you willing to overlook and/or able to work around.

What he said.

I will still hold that, unless you race competitively, leaf springs are the best value and all around best compromise.

[stab6902]

What he said.

I will still hold that, unless you race competitively, leaf springs are the best value and all around best compromise.

I fully agree.

Some people have the idea in their head that it has to be the fanciest, most expensive aftermarket thing in the catalog to be any good. That's just not the case.

It's common to see well setup leaf spring (and stock subframe) cars put up better times than 4-Link/aftermarket subframe cars. Sure, once you get them dialed in many (not all) of the aftermarket setups are better than stock, but we're talking big-time diminishing returns vs the simple spring/shock/swaybar upgrades.

[Steve Chryssos]

What he said.

I will still hold that, unless you race competitively, leaf springs are the best value and all around best compromise.

I used to believe that. But when I converted to link-type suspension, ride quality improved dramatically. The difference is night and day. Relatively speaking, my car went from a covered wagon to a Cadillac. You also can't beat the adjustability. I fine tuned ride height precisely so that my car sits exactly how I want it. That's two features that have little or nothing to do with racing competitively.

[Steve Chryssos]

For the record, I'm not disparaging leaf springs. If that's what you have and can afford, make the most of it. It's good to clarify that a leaf spring is a spring and a link, while with link-type suspension (4-link, 3-link, torque arm, etc., a link is a link. It's job is singularly focused.
Thanks,
Steve

[Shotaro]

For the record, I'm not disparaging leaf springs. If that's what you have and can afford, make the most of it. It's good to clarify that a leaf spring is a spring and a link, while with link-type suspension (4-link, 3-link, torque arm, etc., a link is a link. It's job is singularly focused.
Thanks,
Steve

Okay thank you....
I think....... every day hahaha

[68Formula]

Okay thank you....
I think....... every day hahaha

What year is that? With the multi-leafs, I would expect your shocks to be staggered mounted left to right.

[Shotaro]

What year is that? With the multi-leafs, I would expect your shocks to be staggered mounted left to right.

1970camaro. Detroit speed leaf spring and qa1 shock

[badazz81z28]

I love the leafs versus 4 link arguement. Usually the people who sell leafs jump in a defend it to death. Leafs are so good though...that’s why they are no longer a production thing on sport cars. The Camaro dropped them in 1982....30+ years ago! Even my Dodge Ram has a 4-link from the factory. Face the facts...there are advancements out there if you want to spend the money

[silvermonte]

Kinda off topic but along the same idea, does anyone know where to get some decent "track/autox" leafs for a s10. I dont want to spend the money right now on a 3 or 4 link, spent good money on the front ends first and figured I would get to the back at a later time and just get the truck on the road sooner.

[cornfedbill]

I love the leafs versus 4 link arguement. Usually the people who sell leafs jump in a defend it to death. Leafs are so good though...that’s why they are no longer a production thing on sport cars. The Camaro dropped them in 1982....30+ years ago! Even my Dodge Ram has a 4-link from the factory. Face the facts...there are advancements out there if you want to spend the money

Yup, "If you want to spend the money." It is all about money. Keeping leaf springs on a leaf spring equipped car is the lowest cost alternative. It saves time also.

[badazz81z28]

Yup, "If you want to spend the money." It is all about money. Keeping leaf springs on a leaf spring equipped car is the lowest cost alternative. It saves time also.

Rebuilding a 350 over a LS swap saves money. I’ll spend the money...life’s too short