Leaf springs 3.5 vs 5.5 lift and suspension stretch question?

[Geiri]

This might be a dumb question. But I am wondering about leaf springs do 5.5 springs stretch more than 3.5?
Are there a Characteristic differences between these two?
Is the lift the only difference?

I am looking for a good flexing leaf suspension with great stretch. Something to drive in the Dunes at high speed.

 

[DirtDonk]

It’s not just about the leafspring. It’s a whole system.
If you want more stretch, you’re gonna have to get a longer shackle. If you have an a longer shackle, you’re gonna have to stretch your parking, brake cables and brake hose and driveshaft and shocks as well.
Maybe you know that already and are just asking about the springs specifically. Just wanted to bring up the fact that there’s more to it than just that.

But in general terms, there’s very little difference and stretch in most cases between a 3 1/2 and a 5 1/2.
Of course, there’s more to it than that to end I am speaking generically of off the shelf packages. You can have longer leaf packs used with longer shackles, but you still have to get into the custom stuff at that point.

If you really want to go fast in the dunes, though, you probably want to think about something different than leaf springs.
There’s a precedent for using leaves. But also for other types.

 

[Apogee]

If you're really looking to do high-speed stuff, links and coilovers/bypass shocks are your friend, though leafs can be made to work as noted above. Lots of leaf spring tech on the desert racing forums and how to make them work as well as they can through the high-speed stuff, but they'll always have limits and springs that tend to travel well also tend to have issues with axle wrap, so plan on addressing that at the same time.

As for flex, my 3.5" leaf springs tend to flex better than the 5.5" springs from the same manufacturer (CAGE/Betts), though longer springs with longer shackles would be required for more travel.

 

[Geiri]

@DirtDonk I know all those things need to match
@Apogee those are very expensive compared to leaf springs and Coil Springs. I think? What does it cost to buy something like that for your Bronco?


I am trying to simple but effective.
I think Leaf springs are under rated in many ways. They are usually super strong and trouble free once setup correctly. I have been looking at @migs shackles

 

[Geiri]

As for flex, my 3.5" leaf springs tend to flex better than the 5.5" springs from the same manufacturer (CAGE/Betts), though longer springs with longer shackles would be required for more travel.

That was the info I was looking for

 

[DirtDonk]

They are all of those things for sure.
And certainly more reasonably priced than most other options.
With the balance characteristics of a bronco, does flexy and good travel with a leaf spring equate with good handling in the dunes? I’m not really sure, which is why I’m asking.
Maybe with the right shocks, even going with softer duals, could still be a workable answer.

With nicely trussed/gusseted axle housings of course. Plenty of front long-side tubes have met untimely demises in the sand.

 

[nvrstuk]

Longer wheelbase is needed too! Isn't 100% necessary but sure helps.

Long leaf springs, bump stops and shocks, Did I mention shocks?

Going fast usually means spending money... and longer wheelbase- did I mention that already?

 

[migs]

I built this one to be a good general do it all kind of rig, from daily driving it anywhere, to rock crawling and to handling some bumps at speed.
It has 3.5" springs from Wild Horses- coils up front and leaf springs in the rear, longer radius arms, and Bilstein 7100 shocks. I've been extremely pleased with the results. The suspension has a lot of flex and travel, I wanted to get as much down travel as I could to help keep the tires planted whether crawling or at speed.
Here's some pics of it drooping and flexing. The red Bronco shown in a couple of the pictures is built very similar but has a rear link arm and coil set up, and he drives that rig all over the country and wheels it hard.

 

[nvrstuk]

"Drive in the dunes at high speed".... what is high speed and what are dunes?

20mph or 60mph in whoops from 12"-18" high about 4'-8' apart which seems typical from quad, sxs and 4x4 use on sand trails around dunes or just plain dunes with no whoops but razor backs or jumping or ???

I re-read the OP's first post about dune running. Guess all I have is my experience and it's not racing by any means or being able to pit crew for a racing team (which would be a ton of fun). Just 45yrs with the same EB and several totally different suspensions on it.

Stock- is stock. Compromise at everything but it worked in '66.

Duffs 3.5" lift combo back in '98. Huge quality of ride differentce, great flex. Noticeable dune running difference over stock

Custom rate springs designed by an engineer who spec'd out springs for one of the big Bronco houses. 7100 Bilsteins custom valved by Lee and same with the 5165's for the rear when they came out. 4" Fox bumpstops and huge improvement. Worked great, better ride, much better on dune whoops- 20mph over the whoops I only go slow over before.

Several more tweaks and upgrades and not much difference over the next 20 yrs until 2017.

16" ORI's, 4 link ,100" wheelbase, outside tire track width is 84" and it makes night and day difference. Same basic whoops I was maxed out at 20mph before I have skimmed over at over 60mph for a half mile. Need to put bumpstops back on and an anti-swap bar and I think I'm good for what a short, narrow EB "needs" for a decade until some new "magnetic levitation" suspention comes out! lol

Hope what I've evolved slowly thru in decades of redesigning helps explain what diffeent suspension combinations can do for dune running.

Guys who have designed race suspensions can add a TON of more useable info here. Usually that stuff comes with a price tho.

Best of luck on your build