leaf under/leaf over

[motorbill87]

what are the pros/cons of a leaf under as opposed to leaf over setup?

i'm planning on putting a set of chevy 64" leafs with the beltech shackles on the rear of my truck but I like the stance it has now. I'm also going to have them re-arched 12" and putting an explorer 8.8 in it.

Mostly wanting to do this to improve ride quality and I want more flex than stock. Kinda want to run them as a leaf under setup due to the fact that I don't want much lift out of all this. has anyone set their truck up like this? Is there any setbacks to going leaf under?

thanks for any info

 

[brinker88]

SUA will almost completely eliminate axle wrap. Stock 64s will give you 2" of lift. BUT if you use SUA, you will lose 4-5" in height. So you'll sit 2-3" lower with that setup.

SOA give you plenty of height. I would personally get Ruffstuff or Ballistic Fab spring perches (they're around 8" long to eliminate axle wrap on SOA configs).

 

[motorbill87]

well seeing as to how the exploders had SUA, i'm leaving the factory perches on the axle and I'll probably just go that route.

If I go SUA, and re-arch the springs 12" I dont forsee much of a loss in height over stock. Thats what i'm really trying to figure out

 

[railman]

by re-arching the leaves you will lose flex....

l8r, John

 

[tempforce]

install new spring hangers from and rear. use longer springs with a bit more arch. the arch reduces flex, the long spring increases flex. between the two you should be able to make up for the 4" loss for going under axle. and still have a nice ride.
the other option is to go to a 4 link. and adjustable coil overs / air bags..or air shocks.
air shocks if danger of a punture of a bag.. they have less travel and less control..

 

[motorbill87]

install new spring hangers from and rear. use longer springs with a bit more arch. the arch reduces flex, the long spring increases flex. between the two you should be able to make up for the 4" loss for going under axle. and still have a nice ride.
the other option is to go to a 4 link. and adjustable coil overs / air bags..or air shocks.
air shocks if danger of a punture of a bag.. they have less travel and less control..

awesome thats what I needed to hear! thanks man.

I wanna go 4 link but thats out of my budget right now. Got the leafs from the local junkyard for around $90, shackles will cost me maybe $60 and the local machine shop will arch em for $50.....better than payin $3000 for a complete 4 link with coils for now lol

thanks again

 

[InsaneRedRooster]

SUA will almost completely eliminate axle wrap. Stock 64s will give you 2" of lift. BUT if you use SUA, you will lose 4-5" in height. So you'll sit 2-3" lower with that setup.

SOA give you plenty of height. I would personally get Ruffstuff or Ballistic Fab spring perches (they're around 8" long to eliminate axle wrap on SOA configs).

Hate to hijack but I have a relevant question. How much lift is gained/lost running chevy 64's rearched 12 inches w/ rear shackle flip on an expo 8.8 swap SOA. I dont believe this is covered in the tech library.

Sent from my LS670 using Tapatalk 2

 

[brinker88]

Stock USED chebby's will give you 2 inches of lift. Highest arch a stock chevy has is 4" Say 3.5 inches used due to sagging. Reach that to 12" will give you about 8 inches of lift MINUS the 3 inches lost on a flipped hanger with a stock shackle.

All in all, I'd say 5-6 inches of actual lift.

 

[InsaneRedRooster]

Stock USED chebby's will give you 2 inches of lift. Highest arch a stock chevy has is 4" Say 3.5 inches used due to sagging. Reach that to 12" will give you about 8 inches of lift MINUS the 3 inches lost on a flipped hanger with a stock shackle.

All in all, I'd say 5-6 inches of actual lift.

Perfect, thank you

Sent from my LS670 using Tapatalk 2

 

[bobbywalter]

re-arch to 12 inches?


that is asking for trouble.

building the spring and shackle hangers to suit your ride height goals with some mildly arched 64's would be ideal.

actual locations to hang the springs to maintain an outside of design arch is a pia and ends up trial and error generally....which costs more in the end.

on the chevy swap you want to copy the original hanger geometry to start and tighten it from there to help hold the re-arch.


spring under will not come close to eliminating axle wrap, but tamps it down.

 

[motorbill87]

so you think re-acrh 6" and bring the hangers in closer? maybe build the hangers to a 2" drop to make up for the leaf under?

 

[alwaysFlOoReD]

I would measure to make sure there is no possibility of spring bind. IMO If the spring ends up flat the spring should be able to go into negative arch rather than coming to a sudden stop.

 

[bobbywalter]

its tough to say for sure.

i have had varied results. on a fullsize bronco we intalled longer leaves and it sagged out bad because i improperly located the hangers based on the 90 degree formula and used too long of a shackle....actually used gm frame hangers and mopar/gm spring packs to soften the ride and get rid of the lift blocks. so we rearched, shortened the shackle to 5 in from 7 and moved the hanger back and used over axle traction bars. rode much stiffer but flexed great still. but i did not see a big enough gain to warrant the effort in the end. sux to me. cause good traction bars and the lift blocks were fine. we swapped a d44 to the front and the original spring/lift block setup out back still out flexed it.

the typical gm arrangement done with the rbv is a gain, even though the typical rbv pack already flexes very well.




trying a 4-6 in re-arch and then lowering and or making custom hangers to make up the difference is what i would do for spring under.

but i would not do spring under....as in either case if you have any type of power and traction your still going to need traction bars of some sort. the ground clearance your giving up is huge depending on where you ride. spring over you can leave the pack as is and adjust the hangers to desired ride height... you can get equal or better ride and increased load capacity in many cases.

its possible spring under with a 6 in re-arch may very well negate any ride advantages.

the exception being hi-speed desert racing where you want to be close as possible to the ground within reason yet still have some travel....and buying deavers made for that is the most cost effective route.

 

[alwaysFlOoReD]

I thought I'd through up some pics of what i have on my truck. It's a '91 ranger being built for short course off road racing. I have 63" chevy mainsprings and, IIRC, three rbv springs mounted spring under. I made mounts for the spring under, check out posts 88 and 90 of my build thread; http://www.therangerstation.com/forums/showthread.php?t=79003&page=6. IIRC the 63" springs and 7" shackle was the same height as my stock spring and shackle set up.
With the 7" chevy lowering shackles on;

I wanted it lower so took off the 7" shackles and installed 3.5" generic shackles;

This was too close and I figured that I might get into spring bind. Then I decided to flip and move the shackle mount back, I used the stock back bottom hole;

And my final [so far] iteration;

I decided on the last position thinking that I should get an extra inch or two of droop and only lose an extra 1/2" of height. I lost a total of 4".

I took it for a quick romp and its hitting the bumpstops too easily. I have to re-arch the springs or go back to spring over. There is some wheel hop but not much. I don't have enough seat time to decide if it's a concern.
Hope that helps,

Richard

 

[bobbywalter]

this looks good. maybe lower the bracket another inch with some angle and plate and tube it across to connect them.

theres similar setups for that reason out there on those trucks that are poor boy....though most guys end up with custom alcan/deaver as it proves out better in the end with no geometry guesswork as it allows you to just do a flip on the back and leave everything in place for the most part..

for the op, i would do like i stated for the stated goals and just be spring over.

racing....spring under all the way.